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Cancer incidence and mortality rates are known to vary between different ethnic groups in New Zealand.1,2 Rectal cancer is one of the few cancers for which Mori have historically lower incidence rates than non-Mori.3 However Mori are more likely to be diagnosed at a more advanced stage of disease or have unknown stage,4,5 and are more likely to die from rectal cancer once diagnosed.4-6 A recent study on survival disparities between Mori and non-Mori colon cancer patients in New Zealand showed that Mori had poorer survival than non-Mori patients, and that patient comorbidity and poorer access and quality of cancer care accounted for most of the excess mortality risk in Mori.7,8 This study involved a detailed review of notes, and included all Mori patients diagnosed in a 8-year period (1996-2003). A second study which included patients over the same period concluded that there was no evidence of disparties in survival between Mori and non-Mori colon cancer patients. This second study was based on routine and administrative data, and included patients in their survival analysis only if they had full TNM or Dukes staging data recorded on the New Zealand Cancer Registry (<40% of patients) and was therefore likely to provide a biased estimate.9 However the situation with rectal cancer is unknown. Treatment for rectal cancer is more complex than that of colon cancer, generally.10 Partly for this reason, guidelines suggest that all patients should be discussed at a multidisciplinary team meeting.10,11 Surgery is the mainstay of treatment for rectal cancer stage I-III patients. Preoperative radiotherapy and both pre and postoperative chemotherapy are often recommended for stage III patients. The use of adjuvant therapies is also recommended for some Stage II patients, but controversy remains. Radiotherapy can be short or long course, with the decision often made in the context of multidisciplinary team meetings. Colorectal cancer is one of the most commonly diagnosed cancers and one of the most common causes of death from cancer in New Zealand. In 2009, colorectal cancer accounted for more than 2800 newly diagnosed cases registered with the New Zealand Cancer Registry (NZCR), and 1200 cases of cancer deaths in New Zealand alone.2 New Zealand and Australia have the highest incidence rates of colorectal cancer worldwide.12 Given the demonstrated ethnic inequalities in colon cancer management for Mori and non-Mori patients in New Zealand,7,13 it is of interest for New Zealand cancer practice to consider whether inequalities in cancer care services and/or outcomes also exist between Mori and non-Mori patients with rectal cancer. As part of a larger study, we studied the management of cancer in a cohort of Mori and non-Mori New Zealanders with a newly diagnosed rectal cancer. We collected data directly from hospitals and cancer centers over the entire North Island, allowing a comprehensive comparison of cancer care offered to Mori and non-Mori patients with rectal cancer. Methods Incident cases of rectal cancer diagnosed between 1 Jan 2006 and 31 Dec 2008 were identified from the NZ Cancer Register, and confirmed on the basis of histological report. Any rectal cancer was eligible for inclusion, but rectosigmoid cancers were excluded. Patients aged 25 years or over at diagnosis, who had no previous diagnosis of rectal cancer, were resident in the North Island and were diagnosed prior to death or post-mortem were eligible for study inclusion. Only 10% of Mori cases occur in the South Island so these were excluded for practical (and resource) reasons. All eligible Mori patients along with a randomly sampled equal number of non-Mori patients were included. Ethnicity was classified on the basis of NZ Cancer Registry data which uses an ever-Mori approach where patients are classified as Mori if they have been identified as Mori on any previous health record, all others are classified as non-Mori. Clinical data were abstracted by a trained oncology nurse (VS) from patients medical records from public hospitals and, where possible, from medical records held by physicians practicing in private. Data were recorded on a standardised study pro-forma, and double-entered into an electronic database. Data were also collected from cancer centers and routine administrative hospital records (National Minimum Dataset), and the national mortality collection. Validation checks were carried out and any discrepancies were resolved by reviewing all relevant data, and reaching consensus. Data included date of diagnosis (defined according to first positive biopsy in histology reports or as recorded by treating clinician), details of patients presentation (including a specified list of comorbid conditions present at the time of diagnosis), tumour characteristics (including tumour grade, tumour size (longest length in mm) and stage at diagnosis (pre-treatment as estimated by the treating clinician or based on clinical data with input from a colorectal surgeon), receipt and timing of treatment (including surgery, chemotherapy, radiotherapy and palliative care), and details of surgical treatment including type of operation [lower anterior resection (LAR), abdominoperineal resection (APR), local excision, palliative], type of surgeon performing operation (general or colorectal surgeon; self-defined in clinic letters or District Health Board records), and postoperative complications (within 30 days). Cancer stage was classified according to the TNM classification system.14 For the purposes of describing the place where definitive surgery was performed, hospitals were categorised into those that were in main centres, smaller centres or those that were private hospitals. Main centre hospitals included North Shore, Auckland, Middlemore, Manukau Super Clinic, Waikato, Palmerston North, Wellington and Christchurch; smaller centre hospitals included Whangarei, Tauranga, Thames, Rotorua, Whakatane, Gisborne, Hawkes Bay, Hutt, New Plymouth, Taranaki, Whanganui and Masterton; while private hospitals included Kensington, MercyAscot, Braemar, and Southern Cross. Although only patients residing in the North Island were included in the study, in one case a patient received treatment in Christchurch, which is therefore included here. For the purposes of describing timing to chemo or radiotherapy, we used first referral, and first receipt for chemo or radiotherapy for each patient. Crude and age-standardised proportions of patients were calculated for each variable for Mori and non-Mori cohorts. Direct standardisation using the total New Zealand cancer population was used to calculate age standardised proportions to adjust for differences in the age structure between the Mori and non-Mori population. P values were calculated from Mantel-Haenszel Chi-squared tests stratified by age group, or by t-test in the case of mean age at diagnosis. Median times between key steps in the cancer care pathway were calculated for the total population and for Mori and non-Mori cohorts. P values for these treatment time variables were calculated from the log-rank test stratified by age group. For analysing receipt and timing of definitive treatment procedures, stage IV patients were excluded. First treatment was defined as earliest of radiotherapy, chemotherapy, definitive surgery, or where colonoscopy with polyp removal was treatment rather than diagnostic. Survey methods were used to produce population estimates for all those with rectal cancer in New Zealand over the time frame of the study. The final Mori and non-Mori samples were therefore weighted to the proportion of the target eligible Mori and non-Mori New Zealand rectal cancer population to produce total group estimates. Cox proportional hazard regression model adjusted for age (continuous variable), stage (categories: I to IV) and tumour grade (categories: well-, moderately- and poorly-differentiated) was used to compare mortality hazard ratios (HR). The proportional hazard assumption was not violated, as graphically evaluated. Follow-up time started at date of diagnosis and ended at date of death from colorectal cancer. Patients who died from other causes were censored at that date, and those who did not die were censored at 31 Dec 2009 (the final date covered by the mortality dataset). All analyses were performed using SAS version 9.2 software. Approval for this study was obtained from the Multi-Regional Ethics Committee (ref. # MEC 10/042/EXP). Results We identified a total of 106 Mori patients diagnosed with rectal cancer who met the eligibility criteria based on NZ Cancer Registry data. All eligible Mori were included along with a randomly selected equal number of eligible non-Mori patients, resulting in an initial sample of 212 patients. After reviewing their medical records we found 8% of patients to be ineligible (patients either had left New Zealand for treatment; were found to have a diagnosis date outside of the study period; or were found to have non-rectal cancer as their primary tumour). This resulted in a final sample of 194 patients (97 Mori and 97 non-Mori), of whom all except three had adenocarcinoma of the rectum. Around two-thirds of Mori and non-Mori rectal cancer patients were male (Table 1). Compared to non-Mori, Mori patients were younger (mean age 63.5 years for Mori vs. 69.2 for non-Mori; p<0.001). There were no significant differences in the overall distributions of tumour grade, size or stage between Mori and non-Mori patients (Table 1), although for both grade and tumour size, more data were missing for Mori patients. Compared with non-Mori patients, Mori were more likely to have comorbid conditions, particularly cardiac arrhythmias (age standardised prevalence 17% for Mori vs. 6% for non-Mori; p=0.02), congestive heart failure (age standardised prevalence 12% for Mori vs. 5% for non-Mori; p=0.05), and chronic pulmonary disease (age standardised prevalence 19% for Mori vs. 7% for non-Mori; p=0.01) (Table 1). Table 1. Characteristics of all study-eligible rectal cancer patients Variables Total (n=194) Mori (n=97) Non-Mori (n=97) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Sex Male Female 128 66 66% 34% 64 33 66% 34% 67% 33% 64 33 66% 34% 66% 34% 0.83 Age (years) 25-49 50-64 65-74 > 75 20 56 67 51 9% 25% 31% 36% 12 33 38 14 12% 34% 39% 14% - - - - 8 23 29 37 8% 24% 30% 38% - - - - - Tumour grade Well differentiated Moderately differentiated Poorly differentiated Missing data 32 110 21 31 20% 57% 10% 14% 12 55 12 12 12% 57% 12% 19% 11% 56% 10% 23% 20 55 9 8 21% 57% 9% 13% 23% 52% 13% 12% 0.20 Tumour size (mm) <20 20-39 40-59 >59 Missing data 14 38 28 17 97 9% 22% 16% 7% 45% 5 16 12 10 34 5% 16% 12% 10% 56% 4% 18% 14% 9% 55% 9 22 16 7 34 9% 23% 16% 7% 44% 9% 25% 16% 7% 43% 0.37 Stage Stage I Stage II Stage III Stage IV Missing data 42 36 70 43 3 21% 18% 40% 20% 2% 22 19 31 24 1 23% 20% 32% 25% 1% 25% 16% 35% 22% 2% 20 17 39 19 2 21% 18% 40% 20% 2% 21% 15% 41% 20% 2% 0.77 Comorbid conditions Angina Hypertension Myocardial infarction Arrhythmia Valvular disease Congestive heart failure Peripheral vascular disease Chronic pulmonary disease Diabetes Other primary cancer Renal disease 23 78 13 24 10 20 7 28 38 18 13 11% 41% 7% 9% 6% 8% 5% 10% 17% 9% 6% 13 38 6 16 4 13 2 19 22 9 7 13% 39% 6% 16% 4% 13% 2% 20% 23% 9% 7% 16% 38% 7% 17% 7% 12% 2% 19% 22% 10% 9% 10 40 7 8 6 7 5 9 16 9 6 10% 41% 7% 8% 6% 7% 5% 9% 16% 9% 6% 9% 35% 6% 6% 6% 5% 4% 7% 14% 8% 5% 0.2 0.44 0.96 0.02 0.98 0.05 0.36 0.01 0.24 0.79 0.32 Abbreviations: n, number; mm, millimeter; PVD, peripheral vascular disease. Notes: a) Population estimates; b) Crude estimates; based on the actual study sample; c) Age-standardised estimates. Most patients with stage I-III disease, both Mori (97%) and non-Mori (98%), underwent definitive surgery (Table 2). Although there were some apparent differences in the types of surgery received among Mori and non-Mori patients, this difference was not statistically significant (p=0.07) (Table 3). The specific procedures included low anterior resection (LAR) (age adjusted proportions 51% Mori vs. 64% non-Mori), and local excision (17% Maori vs. 4% non-Maori). All patients who underwent local resection had stage I disease. Nearly two-thirds of definitive operations were performed by specialist colorectal surgeons for both Mori and non-Mori patients. The proportion of patients recorded as having postoperative complications was similar for Mori and non-Mori although the differences in reoperation rates were close to statistically significant (p=0.13) (Table 3). Most patients (age-standardised 52% of Mori and 57% of non-Mori) underwent their first surgery in hospitals in main centres, while 43% of Mori and 28% of non-Mori had surgery in smaller regional hospitals. In addition, 5% of Mori and 16% of Non-Mori had their first surgery in a private hospital (p=0.04; Table 2). Table 2. Receipt of treatment for stage I-III patients Variables Total (n=148) Mori (n=72) Non-Mori (n=76) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Definitive surgery 144 97% 70 97% 97% 74 97% 98% 0.72 Place of surgery: Main centre 79 55% 38 54% 52% 41 55% 57% 0.87 Smaller centre 51 32% 28 40 % 43% 23 31% 28% 0.15 Private 14 13% 4 6% 5% 10 14% 16% 0.04 Chemotherapyd) Preoperative 41 23% 25 36% 36% 16 22% 25% 0.24 Postoperative 44 25% 26 37% 37% 18 24% 29% 0.33 Radiotherapyd) Preoperative 54 34% 29 41% 44% 25 34% 35% 0.44 Postoperative 14 10% 7 10% 7% 7 \r

Summary

Abstract

Aim

Research shows survival disparities between Mori and non-Mori colon cancer patients, with comorbidity and cancer care being major contributing factors. We studied rectal cancer management and survival in a cohort of Mori and non-Mori patients with a newly diagnosed rectal cancer.

Method

194 Maori and non-Maori patients diagnosed with rectal cancer between 2006 and 2008 were identified from the New Zealand Cancer Registry. Medical records were reviewed and patients compared on presentation, patient and tumour characteristics, and receipt and timing of treatment. Cox regression models were fitted to compare cancer-specific survival.

Results

Compared to non-Mori patients, Mori patients were younger (mean age at diagnosis 63.5 and 69.2 for Mori and Non-Mori respectively; p

Conclusion

The findings suggest both similarities and some differences in treatment and outcomes between Mori and non-Mori rectal cancer patients, but firm conclusions are limited by small sample size.

Author Information

Esther M Swart, Department of Public Health, University of Otago, Wellington; Diana Sarfati, Associate Professor, Department of Public Health, University of Otago, Wellington; Ruth Cunningham, Senior Research Fellow, Department of Public Health, University of Otago, Wellington; Elizabeth Dennett, Senior Lecturer, Department of Surgery and Anaesthesia, University of Otago, Wellington; Virginia Signal, Assistant Research Fellow, Department of Public Health, University of Otago, Wellington; Jason Gurney, Research Fellow, Department of Public Health, University of Otago, Wellington; James Stanley, Senior Research Fellow, Department of Public Health, University of Otago, Wellington

Acknowledgements

C3 (Cancer Care and Comorbidity) is funded by the Health Research Council of New Zealand. The authors acknowledge the contribution of the C3 study team and advisory groups.

Correspondence

Diana Sarfati, Department of Public Health, University of Otago, Wellington, PO Box 7343 Wellington South, New Zealand. Fax: +64 (0)4 3895319

Correspondence Email

diana.sarfati@otago.ac.nz

Competing Interests

None identified

- Blakely T, Shaw C, Atkinson J. Cancer trends: trends in incidence by ethnic and socioeconomic group, New Zealand 1981-2004. Wellington: Ministry of Health, 2010. Ministry of Health. Cancer: New Registrations and Deaths 2009. Wellington: Ministry of Health, 2012. Shah AB, Sarfati D, Blakely T, Atkinson J, Dennett ER. Trends in colorectal cancer incidence rates in New Zealand, 1981-2004. ANZ journal of surgery 2012;82(4):258-64. Robson B, Purdie G, Cormack D. Unequal Impact: Mori and non-Mori cancer statistics 1996-2001. Wellington, New Zealand: Ministry of Health, 2006. Robson B, Harris R. Hauora, Mori standards of health IV. A study of the years 2000-2005. Te R\u014dp\u016b Rangahau Hauora a Eru P\u014dmare: Wellington, New Zealand, 2007. Blakely T, Tobias M, Atkinson J, Yeh L-C HK. Tracking Disparity: Trends in ethnic and socioeconomic inequalities in mortality, 1981-2004. Wellington: Ministry of Health, 2007. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, et al. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. Journal of epidemiology and community health 2010;64(2):117-23. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnic disparities in treatment of Mori and non-Mori New Zealanders with colon cancer. Cancer 2010;116:3205-14. Sammour T, Kahokehr A, Vather R, Connolly A, Hill A. Ethnic disparity in colonic cancer outcomes in New Zealand-biology or an access issue? Colorectal Disease 2010;12:e50-e56. The Association of Coloproctology of Great Britain and Ireland. Guidelines for the Management of Colorectal Cancer. 3rd edition ed. Londen: The Association of Coloproctology of Great Britain and Ireland, 2007. Australian Cancer Network Colorectal Cancer Guidelines Revision Committee. Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer. Sydney: The Cancer Council Australia and Australian Cancer Network, 2005. Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. International journal of cancer. Journal international du cancer 2010;127(12):2893-917. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnicity and management of colon cancer in New Zealand: Do indigenous patients get a worse deal? Cancer 2010;116(13):3205-14. American Joint Committee on Cancer. AJCC Cancer Staging Manual. Springer-Verlag. 7th edition ed. New York, 2010. Cormack D, Robson B, Purdie G, Ratima M, Brown R. Access to Cancer Services for M\u00e4ori. Wellington: Ministry of Health, 2005. Ministry of Health. The New Zealand Palliative Care Strategy. Wellington: Ministry of Health, 2001. Sarfati D, Hill S, Blakely T, Robson B. Is bowel cancer screening important for Maori? The New Zealand medical journal 2010;123(1320):9-12. Sarfati D, Shaw C, Simmonds S. Commentary: Inequalities in cancer screening programmes. International journal of epidemiology 2010;39(3):766-8. Brewer N, Borman B, Sarfati D, Jeffreys M, Fleming ST, Cheng S, et al. Does comorbidity explain the ethnic inequalities in cervical cancer survival in New Zealand? A retrospective cohort study. BMC cancer 2011;11:132. Soeberg M BT, Sarfati D, Tobias M, Costilla R, Carter K, Atkinson J.,. Cancer Trends: Trends in cancer survival by ethnic and socioeconomic group, New Zealand 1991-2004. Wellington: University of Otago and Ministry of Health, 2012. Stevens W, Stevens G, Kolbe J, Cox B. Ethnic differences in the management of lung cancer in New Zealand. Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer 2008;3(3):237-44.-

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Cancer incidence and mortality rates are known to vary between different ethnic groups in New Zealand.1,2 Rectal cancer is one of the few cancers for which Mori have historically lower incidence rates than non-Mori.3 However Mori are more likely to be diagnosed at a more advanced stage of disease or have unknown stage,4,5 and are more likely to die from rectal cancer once diagnosed.4-6 A recent study on survival disparities between Mori and non-Mori colon cancer patients in New Zealand showed that Mori had poorer survival than non-Mori patients, and that patient comorbidity and poorer access and quality of cancer care accounted for most of the excess mortality risk in Mori.7,8 This study involved a detailed review of notes, and included all Mori patients diagnosed in a 8-year period (1996-2003). A second study which included patients over the same period concluded that there was no evidence of disparties in survival between Mori and non-Mori colon cancer patients. This second study was based on routine and administrative data, and included patients in their survival analysis only if they had full TNM or Dukes staging data recorded on the New Zealand Cancer Registry (<40% of patients) and was therefore likely to provide a biased estimate.9 However the situation with rectal cancer is unknown. Treatment for rectal cancer is more complex than that of colon cancer, generally.10 Partly for this reason, guidelines suggest that all patients should be discussed at a multidisciplinary team meeting.10,11 Surgery is the mainstay of treatment for rectal cancer stage I-III patients. Preoperative radiotherapy and both pre and postoperative chemotherapy are often recommended for stage III patients. The use of adjuvant therapies is also recommended for some Stage II patients, but controversy remains. Radiotherapy can be short or long course, with the decision often made in the context of multidisciplinary team meetings. Colorectal cancer is one of the most commonly diagnosed cancers and one of the most common causes of death from cancer in New Zealand. In 2009, colorectal cancer accounted for more than 2800 newly diagnosed cases registered with the New Zealand Cancer Registry (NZCR), and 1200 cases of cancer deaths in New Zealand alone.2 New Zealand and Australia have the highest incidence rates of colorectal cancer worldwide.12 Given the demonstrated ethnic inequalities in colon cancer management for Mori and non-Mori patients in New Zealand,7,13 it is of interest for New Zealand cancer practice to consider whether inequalities in cancer care services and/or outcomes also exist between Mori and non-Mori patients with rectal cancer. As part of a larger study, we studied the management of cancer in a cohort of Mori and non-Mori New Zealanders with a newly diagnosed rectal cancer. We collected data directly from hospitals and cancer centers over the entire North Island, allowing a comprehensive comparison of cancer care offered to Mori and non-Mori patients with rectal cancer. Methods Incident cases of rectal cancer diagnosed between 1 Jan 2006 and 31 Dec 2008 were identified from the NZ Cancer Register, and confirmed on the basis of histological report. Any rectal cancer was eligible for inclusion, but rectosigmoid cancers were excluded. Patients aged 25 years or over at diagnosis, who had no previous diagnosis of rectal cancer, were resident in the North Island and were diagnosed prior to death or post-mortem were eligible for study inclusion. Only 10% of Mori cases occur in the South Island so these were excluded for practical (and resource) reasons. All eligible Mori patients along with a randomly sampled equal number of non-Mori patients were included. Ethnicity was classified on the basis of NZ Cancer Registry data which uses an ever-Mori approach where patients are classified as Mori if they have been identified as Mori on any previous health record, all others are classified as non-Mori. Clinical data were abstracted by a trained oncology nurse (VS) from patients medical records from public hospitals and, where possible, from medical records held by physicians practicing in private. Data were recorded on a standardised study pro-forma, and double-entered into an electronic database. Data were also collected from cancer centers and routine administrative hospital records (National Minimum Dataset), and the national mortality collection. Validation checks were carried out and any discrepancies were resolved by reviewing all relevant data, and reaching consensus. Data included date of diagnosis (defined according to first positive biopsy in histology reports or as recorded by treating clinician), details of patients presentation (including a specified list of comorbid conditions present at the time of diagnosis), tumour characteristics (including tumour grade, tumour size (longest length in mm) and stage at diagnosis (pre-treatment as estimated by the treating clinician or based on clinical data with input from a colorectal surgeon), receipt and timing of treatment (including surgery, chemotherapy, radiotherapy and palliative care), and details of surgical treatment including type of operation [lower anterior resection (LAR), abdominoperineal resection (APR), local excision, palliative], type of surgeon performing operation (general or colorectal surgeon; self-defined in clinic letters or District Health Board records), and postoperative complications (within 30 days). Cancer stage was classified according to the TNM classification system.14 For the purposes of describing the place where definitive surgery was performed, hospitals were categorised into those that were in main centres, smaller centres or those that were private hospitals. Main centre hospitals included North Shore, Auckland, Middlemore, Manukau Super Clinic, Waikato, Palmerston North, Wellington and Christchurch; smaller centre hospitals included Whangarei, Tauranga, Thames, Rotorua, Whakatane, Gisborne, Hawkes Bay, Hutt, New Plymouth, Taranaki, Whanganui and Masterton; while private hospitals included Kensington, MercyAscot, Braemar, and Southern Cross. Although only patients residing in the North Island were included in the study, in one case a patient received treatment in Christchurch, which is therefore included here. For the purposes of describing timing to chemo or radiotherapy, we used first referral, and first receipt for chemo or radiotherapy for each patient. Crude and age-standardised proportions of patients were calculated for each variable for Mori and non-Mori cohorts. Direct standardisation using the total New Zealand cancer population was used to calculate age standardised proportions to adjust for differences in the age structure between the Mori and non-Mori population. P values were calculated from Mantel-Haenszel Chi-squared tests stratified by age group, or by t-test in the case of mean age at diagnosis. Median times between key steps in the cancer care pathway were calculated for the total population and for Mori and non-Mori cohorts. P values for these treatment time variables were calculated from the log-rank test stratified by age group. For analysing receipt and timing of definitive treatment procedures, stage IV patients were excluded. First treatment was defined as earliest of radiotherapy, chemotherapy, definitive surgery, or where colonoscopy with polyp removal was treatment rather than diagnostic. Survey methods were used to produce population estimates for all those with rectal cancer in New Zealand over the time frame of the study. The final Mori and non-Mori samples were therefore weighted to the proportion of the target eligible Mori and non-Mori New Zealand rectal cancer population to produce total group estimates. Cox proportional hazard regression model adjusted for age (continuous variable), stage (categories: I to IV) and tumour grade (categories: well-, moderately- and poorly-differentiated) was used to compare mortality hazard ratios (HR). The proportional hazard assumption was not violated, as graphically evaluated. Follow-up time started at date of diagnosis and ended at date of death from colorectal cancer. Patients who died from other causes were censored at that date, and those who did not die were censored at 31 Dec 2009 (the final date covered by the mortality dataset). All analyses were performed using SAS version 9.2 software. Approval for this study was obtained from the Multi-Regional Ethics Committee (ref. # MEC 10/042/EXP). Results We identified a total of 106 Mori patients diagnosed with rectal cancer who met the eligibility criteria based on NZ Cancer Registry data. All eligible Mori were included along with a randomly selected equal number of eligible non-Mori patients, resulting in an initial sample of 212 patients. After reviewing their medical records we found 8% of patients to be ineligible (patients either had left New Zealand for treatment; were found to have a diagnosis date outside of the study period; or were found to have non-rectal cancer as their primary tumour). This resulted in a final sample of 194 patients (97 Mori and 97 non-Mori), of whom all except three had adenocarcinoma of the rectum. Around two-thirds of Mori and non-Mori rectal cancer patients were male (Table 1). Compared to non-Mori, Mori patients were younger (mean age 63.5 years for Mori vs. 69.2 for non-Mori; p<0.001). There were no significant differences in the overall distributions of tumour grade, size or stage between Mori and non-Mori patients (Table 1), although for both grade and tumour size, more data were missing for Mori patients. Compared with non-Mori patients, Mori were more likely to have comorbid conditions, particularly cardiac arrhythmias (age standardised prevalence 17% for Mori vs. 6% for non-Mori; p=0.02), congestive heart failure (age standardised prevalence 12% for Mori vs. 5% for non-Mori; p=0.05), and chronic pulmonary disease (age standardised prevalence 19% for Mori vs. 7% for non-Mori; p=0.01) (Table 1). Table 1. Characteristics of all study-eligible rectal cancer patients Variables Total (n=194) Mori (n=97) Non-Mori (n=97) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Sex Male Female 128 66 66% 34% 64 33 66% 34% 67% 33% 64 33 66% 34% 66% 34% 0.83 Age (years) 25-49 50-64 65-74 > 75 20 56 67 51 9% 25% 31% 36% 12 33 38 14 12% 34% 39% 14% - - - - 8 23 29 37 8% 24% 30% 38% - - - - - Tumour grade Well differentiated Moderately differentiated Poorly differentiated Missing data 32 110 21 31 20% 57% 10% 14% 12 55 12 12 12% 57% 12% 19% 11% 56% 10% 23% 20 55 9 8 21% 57% 9% 13% 23% 52% 13% 12% 0.20 Tumour size (mm) <20 20-39 40-59 >59 Missing data 14 38 28 17 97 9% 22% 16% 7% 45% 5 16 12 10 34 5% 16% 12% 10% 56% 4% 18% 14% 9% 55% 9 22 16 7 34 9% 23% 16% 7% 44% 9% 25% 16% 7% 43% 0.37 Stage Stage I Stage II Stage III Stage IV Missing data 42 36 70 43 3 21% 18% 40% 20% 2% 22 19 31 24 1 23% 20% 32% 25% 1% 25% 16% 35% 22% 2% 20 17 39 19 2 21% 18% 40% 20% 2% 21% 15% 41% 20% 2% 0.77 Comorbid conditions Angina Hypertension Myocardial infarction Arrhythmia Valvular disease Congestive heart failure Peripheral vascular disease Chronic pulmonary disease Diabetes Other primary cancer Renal disease 23 78 13 24 10 20 7 28 38 18 13 11% 41% 7% 9% 6% 8% 5% 10% 17% 9% 6% 13 38 6 16 4 13 2 19 22 9 7 13% 39% 6% 16% 4% 13% 2% 20% 23% 9% 7% 16% 38% 7% 17% 7% 12% 2% 19% 22% 10% 9% 10 40 7 8 6 7 5 9 16 9 6 10% 41% 7% 8% 6% 7% 5% 9% 16% 9% 6% 9% 35% 6% 6% 6% 5% 4% 7% 14% 8% 5% 0.2 0.44 0.96 0.02 0.98 0.05 0.36 0.01 0.24 0.79 0.32 Abbreviations: n, number; mm, millimeter; PVD, peripheral vascular disease. Notes: a) Population estimates; b) Crude estimates; based on the actual study sample; c) Age-standardised estimates. Most patients with stage I-III disease, both Mori (97%) and non-Mori (98%), underwent definitive surgery (Table 2). Although there were some apparent differences in the types of surgery received among Mori and non-Mori patients, this difference was not statistically significant (p=0.07) (Table 3). The specific procedures included low anterior resection (LAR) (age adjusted proportions 51% Mori vs. 64% non-Mori), and local excision (17% Maori vs. 4% non-Maori). All patients who underwent local resection had stage I disease. Nearly two-thirds of definitive operations were performed by specialist colorectal surgeons for both Mori and non-Mori patients. The proportion of patients recorded as having postoperative complications was similar for Mori and non-Mori although the differences in reoperation rates were close to statistically significant (p=0.13) (Table 3). Most patients (age-standardised 52% of Mori and 57% of non-Mori) underwent their first surgery in hospitals in main centres, while 43% of Mori and 28% of non-Mori had surgery in smaller regional hospitals. In addition, 5% of Mori and 16% of Non-Mori had their first surgery in a private hospital (p=0.04; Table 2). Table 2. Receipt of treatment for stage I-III patients Variables Total (n=148) Mori (n=72) Non-Mori (n=76) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Definitive surgery 144 97% 70 97% 97% 74 97% 98% 0.72 Place of surgery: Main centre 79 55% 38 54% 52% 41 55% 57% 0.87 Smaller centre 51 32% 28 40 % 43% 23 31% 28% 0.15 Private 14 13% 4 6% 5% 10 14% 16% 0.04 Chemotherapyd) Preoperative 41 23% 25 36% 36% 16 22% 25% 0.24 Postoperative 44 25% 26 37% 37% 18 24% 29% 0.33 Radiotherapyd) Preoperative 54 34% 29 41% 44% 25 34% 35% 0.44 Postoperative 14 10% 7 10% 7% 7 \r

Summary

Abstract

Aim

Research shows survival disparities between Mori and non-Mori colon cancer patients, with comorbidity and cancer care being major contributing factors. We studied rectal cancer management and survival in a cohort of Mori and non-Mori patients with a newly diagnosed rectal cancer.

Method

194 Maori and non-Maori patients diagnosed with rectal cancer between 2006 and 2008 were identified from the New Zealand Cancer Registry. Medical records were reviewed and patients compared on presentation, patient and tumour characteristics, and receipt and timing of treatment. Cox regression models were fitted to compare cancer-specific survival.

Results

Compared to non-Mori patients, Mori patients were younger (mean age at diagnosis 63.5 and 69.2 for Mori and Non-Mori respectively; p

Conclusion

The findings suggest both similarities and some differences in treatment and outcomes between Mori and non-Mori rectal cancer patients, but firm conclusions are limited by small sample size.

Author Information

Esther M Swart, Department of Public Health, University of Otago, Wellington; Diana Sarfati, Associate Professor, Department of Public Health, University of Otago, Wellington; Ruth Cunningham, Senior Research Fellow, Department of Public Health, University of Otago, Wellington; Elizabeth Dennett, Senior Lecturer, Department of Surgery and Anaesthesia, University of Otago, Wellington; Virginia Signal, Assistant Research Fellow, Department of Public Health, University of Otago, Wellington; Jason Gurney, Research Fellow, Department of Public Health, University of Otago, Wellington; James Stanley, Senior Research Fellow, Department of Public Health, University of Otago, Wellington

Acknowledgements

C3 (Cancer Care and Comorbidity) is funded by the Health Research Council of New Zealand. The authors acknowledge the contribution of the C3 study team and advisory groups.

Correspondence

Diana Sarfati, Department of Public Health, University of Otago, Wellington, PO Box 7343 Wellington South, New Zealand. Fax: +64 (0)4 3895319

Correspondence Email

diana.sarfati@otago.ac.nz

Competing Interests

None identified

- Blakely T, Shaw C, Atkinson J. Cancer trends: trends in incidence by ethnic and socioeconomic group, New Zealand 1981-2004. Wellington: Ministry of Health, 2010. Ministry of Health. Cancer: New Registrations and Deaths 2009. Wellington: Ministry of Health, 2012. Shah AB, Sarfati D, Blakely T, Atkinson J, Dennett ER. Trends in colorectal cancer incidence rates in New Zealand, 1981-2004. ANZ journal of surgery 2012;82(4):258-64. Robson B, Purdie G, Cormack D. Unequal Impact: Mori and non-Mori cancer statistics 1996-2001. Wellington, New Zealand: Ministry of Health, 2006. Robson B, Harris R. Hauora, Mori standards of health IV. A study of the years 2000-2005. Te R\u014dp\u016b Rangahau Hauora a Eru P\u014dmare: Wellington, New Zealand, 2007. Blakely T, Tobias M, Atkinson J, Yeh L-C HK. Tracking Disparity: Trends in ethnic and socioeconomic inequalities in mortality, 1981-2004. Wellington: Ministry of Health, 2007. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, et al. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. Journal of epidemiology and community health 2010;64(2):117-23. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnic disparities in treatment of Mori and non-Mori New Zealanders with colon cancer. Cancer 2010;116:3205-14. Sammour T, Kahokehr A, Vather R, Connolly A, Hill A. Ethnic disparity in colonic cancer outcomes in New Zealand-biology or an access issue? Colorectal Disease 2010;12:e50-e56. The Association of Coloproctology of Great Britain and Ireland. Guidelines for the Management of Colorectal Cancer. 3rd edition ed. Londen: The Association of Coloproctology of Great Britain and Ireland, 2007. Australian Cancer Network Colorectal Cancer Guidelines Revision Committee. Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer. Sydney: The Cancer Council Australia and Australian Cancer Network, 2005. Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. International journal of cancer. Journal international du cancer 2010;127(12):2893-917. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnicity and management of colon cancer in New Zealand: Do indigenous patients get a worse deal? Cancer 2010;116(13):3205-14. American Joint Committee on Cancer. AJCC Cancer Staging Manual. Springer-Verlag. 7th edition ed. New York, 2010. Cormack D, Robson B, Purdie G, Ratima M, Brown R. Access to Cancer Services for M\u00e4ori. Wellington: Ministry of Health, 2005. Ministry of Health. The New Zealand Palliative Care Strategy. Wellington: Ministry of Health, 2001. Sarfati D, Hill S, Blakely T, Robson B. Is bowel cancer screening important for Maori? The New Zealand medical journal 2010;123(1320):9-12. Sarfati D, Shaw C, Simmonds S. Commentary: Inequalities in cancer screening programmes. International journal of epidemiology 2010;39(3):766-8. Brewer N, Borman B, Sarfati D, Jeffreys M, Fleming ST, Cheng S, et al. Does comorbidity explain the ethnic inequalities in cervical cancer survival in New Zealand? A retrospective cohort study. BMC cancer 2011;11:132. Soeberg M BT, Sarfati D, Tobias M, Costilla R, Carter K, Atkinson J.,. Cancer Trends: Trends in cancer survival by ethnic and socioeconomic group, New Zealand 1991-2004. Wellington: University of Otago and Ministry of Health, 2012. Stevens W, Stevens G, Kolbe J, Cox B. Ethnic differences in the management of lung cancer in New Zealand. Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer 2008;3(3):237-44.-

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Cancer incidence and mortality rates are known to vary between different ethnic groups in New Zealand.1,2 Rectal cancer is one of the few cancers for which Mori have historically lower incidence rates than non-Mori.3 However Mori are more likely to be diagnosed at a more advanced stage of disease or have unknown stage,4,5 and are more likely to die from rectal cancer once diagnosed.4-6 A recent study on survival disparities between Mori and non-Mori colon cancer patients in New Zealand showed that Mori had poorer survival than non-Mori patients, and that patient comorbidity and poorer access and quality of cancer care accounted for most of the excess mortality risk in Mori.7,8 This study involved a detailed review of notes, and included all Mori patients diagnosed in a 8-year period (1996-2003). A second study which included patients over the same period concluded that there was no evidence of disparties in survival between Mori and non-Mori colon cancer patients. This second study was based on routine and administrative data, and included patients in their survival analysis only if they had full TNM or Dukes staging data recorded on the New Zealand Cancer Registry (<40% of patients) and was therefore likely to provide a biased estimate.9 However the situation with rectal cancer is unknown. Treatment for rectal cancer is more complex than that of colon cancer, generally.10 Partly for this reason, guidelines suggest that all patients should be discussed at a multidisciplinary team meeting.10,11 Surgery is the mainstay of treatment for rectal cancer stage I-III patients. Preoperative radiotherapy and both pre and postoperative chemotherapy are often recommended for stage III patients. The use of adjuvant therapies is also recommended for some Stage II patients, but controversy remains. Radiotherapy can be short or long course, with the decision often made in the context of multidisciplinary team meetings. Colorectal cancer is one of the most commonly diagnosed cancers and one of the most common causes of death from cancer in New Zealand. In 2009, colorectal cancer accounted for more than 2800 newly diagnosed cases registered with the New Zealand Cancer Registry (NZCR), and 1200 cases of cancer deaths in New Zealand alone.2 New Zealand and Australia have the highest incidence rates of colorectal cancer worldwide.12 Given the demonstrated ethnic inequalities in colon cancer management for Mori and non-Mori patients in New Zealand,7,13 it is of interest for New Zealand cancer practice to consider whether inequalities in cancer care services and/or outcomes also exist between Mori and non-Mori patients with rectal cancer. As part of a larger study, we studied the management of cancer in a cohort of Mori and non-Mori New Zealanders with a newly diagnosed rectal cancer. We collected data directly from hospitals and cancer centers over the entire North Island, allowing a comprehensive comparison of cancer care offered to Mori and non-Mori patients with rectal cancer. Methods Incident cases of rectal cancer diagnosed between 1 Jan 2006 and 31 Dec 2008 were identified from the NZ Cancer Register, and confirmed on the basis of histological report. Any rectal cancer was eligible for inclusion, but rectosigmoid cancers were excluded. Patients aged 25 years or over at diagnosis, who had no previous diagnosis of rectal cancer, were resident in the North Island and were diagnosed prior to death or post-mortem were eligible for study inclusion. Only 10% of Mori cases occur in the South Island so these were excluded for practical (and resource) reasons. All eligible Mori patients along with a randomly sampled equal number of non-Mori patients were included. Ethnicity was classified on the basis of NZ Cancer Registry data which uses an ever-Mori approach where patients are classified as Mori if they have been identified as Mori on any previous health record, all others are classified as non-Mori. Clinical data were abstracted by a trained oncology nurse (VS) from patients medical records from public hospitals and, where possible, from medical records held by physicians practicing in private. Data were recorded on a standardised study pro-forma, and double-entered into an electronic database. Data were also collected from cancer centers and routine administrative hospital records (National Minimum Dataset), and the national mortality collection. Validation checks were carried out and any discrepancies were resolved by reviewing all relevant data, and reaching consensus. Data included date of diagnosis (defined according to first positive biopsy in histology reports or as recorded by treating clinician), details of patients presentation (including a specified list of comorbid conditions present at the time of diagnosis), tumour characteristics (including tumour grade, tumour size (longest length in mm) and stage at diagnosis (pre-treatment as estimated by the treating clinician or based on clinical data with input from a colorectal surgeon), receipt and timing of treatment (including surgery, chemotherapy, radiotherapy and palliative care), and details of surgical treatment including type of operation [lower anterior resection (LAR), abdominoperineal resection (APR), local excision, palliative], type of surgeon performing operation (general or colorectal surgeon; self-defined in clinic letters or District Health Board records), and postoperative complications (within 30 days). Cancer stage was classified according to the TNM classification system.14 For the purposes of describing the place where definitive surgery was performed, hospitals were categorised into those that were in main centres, smaller centres or those that were private hospitals. Main centre hospitals included North Shore, Auckland, Middlemore, Manukau Super Clinic, Waikato, Palmerston North, Wellington and Christchurch; smaller centre hospitals included Whangarei, Tauranga, Thames, Rotorua, Whakatane, Gisborne, Hawkes Bay, Hutt, New Plymouth, Taranaki, Whanganui and Masterton; while private hospitals included Kensington, MercyAscot, Braemar, and Southern Cross. Although only patients residing in the North Island were included in the study, in one case a patient received treatment in Christchurch, which is therefore included here. For the purposes of describing timing to chemo or radiotherapy, we used first referral, and first receipt for chemo or radiotherapy for each patient. Crude and age-standardised proportions of patients were calculated for each variable for Mori and non-Mori cohorts. Direct standardisation using the total New Zealand cancer population was used to calculate age standardised proportions to adjust for differences in the age structure between the Mori and non-Mori population. P values were calculated from Mantel-Haenszel Chi-squared tests stratified by age group, or by t-test in the case of mean age at diagnosis. Median times between key steps in the cancer care pathway were calculated for the total population and for Mori and non-Mori cohorts. P values for these treatment time variables were calculated from the log-rank test stratified by age group. For analysing receipt and timing of definitive treatment procedures, stage IV patients were excluded. First treatment was defined as earliest of radiotherapy, chemotherapy, definitive surgery, or where colonoscopy with polyp removal was treatment rather than diagnostic. Survey methods were used to produce population estimates for all those with rectal cancer in New Zealand over the time frame of the study. The final Mori and non-Mori samples were therefore weighted to the proportion of the target eligible Mori and non-Mori New Zealand rectal cancer population to produce total group estimates. Cox proportional hazard regression model adjusted for age (continuous variable), stage (categories: I to IV) and tumour grade (categories: well-, moderately- and poorly-differentiated) was used to compare mortality hazard ratios (HR). The proportional hazard assumption was not violated, as graphically evaluated. Follow-up time started at date of diagnosis and ended at date of death from colorectal cancer. Patients who died from other causes were censored at that date, and those who did not die were censored at 31 Dec 2009 (the final date covered by the mortality dataset). All analyses were performed using SAS version 9.2 software. Approval for this study was obtained from the Multi-Regional Ethics Committee (ref. # MEC 10/042/EXP). Results We identified a total of 106 Mori patients diagnosed with rectal cancer who met the eligibility criteria based on NZ Cancer Registry data. All eligible Mori were included along with a randomly selected equal number of eligible non-Mori patients, resulting in an initial sample of 212 patients. After reviewing their medical records we found 8% of patients to be ineligible (patients either had left New Zealand for treatment; were found to have a diagnosis date outside of the study period; or were found to have non-rectal cancer as their primary tumour). This resulted in a final sample of 194 patients (97 Mori and 97 non-Mori), of whom all except three had adenocarcinoma of the rectum. Around two-thirds of Mori and non-Mori rectal cancer patients were male (Table 1). Compared to non-Mori, Mori patients were younger (mean age 63.5 years for Mori vs. 69.2 for non-Mori; p<0.001). There were no significant differences in the overall distributions of tumour grade, size or stage between Mori and non-Mori patients (Table 1), although for both grade and tumour size, more data were missing for Mori patients. Compared with non-Mori patients, Mori were more likely to have comorbid conditions, particularly cardiac arrhythmias (age standardised prevalence 17% for Mori vs. 6% for non-Mori; p=0.02), congestive heart failure (age standardised prevalence 12% for Mori vs. 5% for non-Mori; p=0.05), and chronic pulmonary disease (age standardised prevalence 19% for Mori vs. 7% for non-Mori; p=0.01) (Table 1). Table 1. Characteristics of all study-eligible rectal cancer patients Variables Total (n=194) Mori (n=97) Non-Mori (n=97) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Sex Male Female 128 66 66% 34% 64 33 66% 34% 67% 33% 64 33 66% 34% 66% 34% 0.83 Age (years) 25-49 50-64 65-74 > 75 20 56 67 51 9% 25% 31% 36% 12 33 38 14 12% 34% 39% 14% - - - - 8 23 29 37 8% 24% 30% 38% - - - - - Tumour grade Well differentiated Moderately differentiated Poorly differentiated Missing data 32 110 21 31 20% 57% 10% 14% 12 55 12 12 12% 57% 12% 19% 11% 56% 10% 23% 20 55 9 8 21% 57% 9% 13% 23% 52% 13% 12% 0.20 Tumour size (mm) <20 20-39 40-59 >59 Missing data 14 38 28 17 97 9% 22% 16% 7% 45% 5 16 12 10 34 5% 16% 12% 10% 56% 4% 18% 14% 9% 55% 9 22 16 7 34 9% 23% 16% 7% 44% 9% 25% 16% 7% 43% 0.37 Stage Stage I Stage II Stage III Stage IV Missing data 42 36 70 43 3 21% 18% 40% 20% 2% 22 19 31 24 1 23% 20% 32% 25% 1% 25% 16% 35% 22% 2% 20 17 39 19 2 21% 18% 40% 20% 2% 21% 15% 41% 20% 2% 0.77 Comorbid conditions Angina Hypertension Myocardial infarction Arrhythmia Valvular disease Congestive heart failure Peripheral vascular disease Chronic pulmonary disease Diabetes Other primary cancer Renal disease 23 78 13 24 10 20 7 28 38 18 13 11% 41% 7% 9% 6% 8% 5% 10% 17% 9% 6% 13 38 6 16 4 13 2 19 22 9 7 13% 39% 6% 16% 4% 13% 2% 20% 23% 9% 7% 16% 38% 7% 17% 7% 12% 2% 19% 22% 10% 9% 10 40 7 8 6 7 5 9 16 9 6 10% 41% 7% 8% 6% 7% 5% 9% 16% 9% 6% 9% 35% 6% 6% 6% 5% 4% 7% 14% 8% 5% 0.2 0.44 0.96 0.02 0.98 0.05 0.36 0.01 0.24 0.79 0.32 Abbreviations: n, number; mm, millimeter; PVD, peripheral vascular disease. Notes: a) Population estimates; b) Crude estimates; based on the actual study sample; c) Age-standardised estimates. Most patients with stage I-III disease, both Mori (97%) and non-Mori (98%), underwent definitive surgery (Table 2). Although there were some apparent differences in the types of surgery received among Mori and non-Mori patients, this difference was not statistically significant (p=0.07) (Table 3). The specific procedures included low anterior resection (LAR) (age adjusted proportions 51% Mori vs. 64% non-Mori), and local excision (17% Maori vs. 4% non-Maori). All patients who underwent local resection had stage I disease. Nearly two-thirds of definitive operations were performed by specialist colorectal surgeons for both Mori and non-Mori patients. The proportion of patients recorded as having postoperative complications was similar for Mori and non-Mori although the differences in reoperation rates were close to statistically significant (p=0.13) (Table 3). Most patients (age-standardised 52% of Mori and 57% of non-Mori) underwent their first surgery in hospitals in main centres, while 43% of Mori and 28% of non-Mori had surgery in smaller regional hospitals. In addition, 5% of Mori and 16% of Non-Mori had their first surgery in a private hospital (p=0.04; Table 2). Table 2. Receipt of treatment for stage I-III patients Variables Total (n=148) Mori (n=72) Non-Mori (n=76) P value n %a) n Crude %b) Adj %c) n Crude %b) Adj %c) Definitive surgery 144 97% 70 97% 97% 74 97% 98% 0.72 Place of surgery: Main centre 79 55% 38 54% 52% 41 55% 57% 0.87 Smaller centre 51 32% 28 40 % 43% 23 31% 28% 0.15 Private 14 13% 4 6% 5% 10 14% 16% 0.04 Chemotherapyd) Preoperative 41 23% 25 36% 36% 16 22% 25% 0.24 Postoperative 44 25% 26 37% 37% 18 24% 29% 0.33 Radiotherapyd) Preoperative 54 34% 29 41% 44% 25 34% 35% 0.44 Postoperative 14 10% 7 10% 7% 7 \r

Summary

Abstract

Aim

Research shows survival disparities between Mori and non-Mori colon cancer patients, with comorbidity and cancer care being major contributing factors. We studied rectal cancer management and survival in a cohort of Mori and non-Mori patients with a newly diagnosed rectal cancer.

Method

194 Maori and non-Maori patients diagnosed with rectal cancer between 2006 and 2008 were identified from the New Zealand Cancer Registry. Medical records were reviewed and patients compared on presentation, patient and tumour characteristics, and receipt and timing of treatment. Cox regression models were fitted to compare cancer-specific survival.

Results

Compared to non-Mori patients, Mori patients were younger (mean age at diagnosis 63.5 and 69.2 for Mori and Non-Mori respectively; p

Conclusion

The findings suggest both similarities and some differences in treatment and outcomes between Mori and non-Mori rectal cancer patients, but firm conclusions are limited by small sample size.

Author Information

Esther M Swart, Department of Public Health, University of Otago, Wellington; Diana Sarfati, Associate Professor, Department of Public Health, University of Otago, Wellington; Ruth Cunningham, Senior Research Fellow, Department of Public Health, University of Otago, Wellington; Elizabeth Dennett, Senior Lecturer, Department of Surgery and Anaesthesia, University of Otago, Wellington; Virginia Signal, Assistant Research Fellow, Department of Public Health, University of Otago, Wellington; Jason Gurney, Research Fellow, Department of Public Health, University of Otago, Wellington; James Stanley, Senior Research Fellow, Department of Public Health, University of Otago, Wellington

Acknowledgements

C3 (Cancer Care and Comorbidity) is funded by the Health Research Council of New Zealand. The authors acknowledge the contribution of the C3 study team and advisory groups.

Correspondence

Diana Sarfati, Department of Public Health, University of Otago, Wellington, PO Box 7343 Wellington South, New Zealand. Fax: +64 (0)4 3895319

Correspondence Email

diana.sarfati@otago.ac.nz

Competing Interests

None identified

- Blakely T, Shaw C, Atkinson J. Cancer trends: trends in incidence by ethnic and socioeconomic group, New Zealand 1981-2004. Wellington: Ministry of Health, 2010. Ministry of Health. Cancer: New Registrations and Deaths 2009. Wellington: Ministry of Health, 2012. Shah AB, Sarfati D, Blakely T, Atkinson J, Dennett ER. Trends in colorectal cancer incidence rates in New Zealand, 1981-2004. ANZ journal of surgery 2012;82(4):258-64. Robson B, Purdie G, Cormack D. Unequal Impact: Mori and non-Mori cancer statistics 1996-2001. Wellington, New Zealand: Ministry of Health, 2006. Robson B, Harris R. Hauora, Mori standards of health IV. A study of the years 2000-2005. Te R\u014dp\u016b Rangahau Hauora a Eru P\u014dmare: Wellington, New Zealand, 2007. Blakely T, Tobias M, Atkinson J, Yeh L-C HK. Tracking Disparity: Trends in ethnic and socioeconomic inequalities in mortality, 1981-2004. Wellington: Ministry of Health, 2007. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, et al. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. Journal of epidemiology and community health 2010;64(2):117-23. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnic disparities in treatment of Mori and non-Mori New Zealanders with colon cancer. Cancer 2010;116:3205-14. Sammour T, Kahokehr A, Vather R, Connolly A, Hill A. Ethnic disparity in colonic cancer outcomes in New Zealand-biology or an access issue? Colorectal Disease 2010;12:e50-e56. The Association of Coloproctology of Great Britain and Ireland. Guidelines for the Management of Colorectal Cancer. 3rd edition ed. Londen: The Association of Coloproctology of Great Britain and Ireland, 2007. Australian Cancer Network Colorectal Cancer Guidelines Revision Committee. Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer. Sydney: The Cancer Council Australia and Australian Cancer Network, 2005. Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. International journal of cancer. Journal international du cancer 2010;127(12):2893-917. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Dennett E, et al. Ethnicity and management of colon cancer in New Zealand: Do indigenous patients get a worse deal? Cancer 2010;116(13):3205-14. American Joint Committee on Cancer. AJCC Cancer Staging Manual. Springer-Verlag. 7th edition ed. New York, 2010. Cormack D, Robson B, Purdie G, Ratima M, Brown R. Access to Cancer Services for M\u00e4ori. Wellington: Ministry of Health, 2005. Ministry of Health. The New Zealand Palliative Care Strategy. Wellington: Ministry of Health, 2001. Sarfati D, Hill S, Blakely T, Robson B. Is bowel cancer screening important for Maori? The New Zealand medical journal 2010;123(1320):9-12. Sarfati D, Shaw C, Simmonds S. Commentary: Inequalities in cancer screening programmes. International journal of epidemiology 2010;39(3):766-8. Brewer N, Borman B, Sarfati D, Jeffreys M, Fleming ST, Cheng S, et al. Does comorbidity explain the ethnic inequalities in cervical cancer survival in New Zealand? A retrospective cohort study. BMC cancer 2011;11:132. Soeberg M BT, Sarfati D, Tobias M, Costilla R, Carter K, Atkinson J.,. Cancer Trends: Trends in cancer survival by ethnic and socioeconomic group, New Zealand 1991-2004. Wellington: University of Otago and Ministry of Health, 2012. Stevens W, Stevens G, Kolbe J, Cox B. Ethnic differences in the management of lung cancer in New Zealand. Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer 2008;3(3):237-44.-

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