Issue

Vol 135 No 1564: 28 October 2022

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Issue Summary

Article
SUMMARY

Improving early detection of colorectal cancer in Aotearoa New Zealand; how do the direct access criteria perform?

In New Zealand, patients with gastrointestinal symptoms can be referred for colonoscopy or other equivalent tests if they meet certain national criteria (which include an age range, symptoms such as the presence of blood in the stool, and whether the patient has a low red blood cell count caused by iron deficiency). Our study looked at all colonoscopy referrals to Christchurch Hospital through this referral pathway during the year 2018 to examine, amongst other outcomes, how the current criteria perform at detecting colon cancer. Of the 3,200 referrals, 128 patients were found to have colon cancer, which is only 4.0% of the referred patients. This can be thought of as the number of colonoscopies needing to be performed to detect one cancer being 25. Due to the pressure on colonoscopy resources in New Zealand, we argue that the current performance of the pathway is inadequate primarily due to the poor performance of a patient’s symptoms alone in determining colon cancer risk, and this leads to a large number of colonoscopies being performed with a low cancer “yield”. An improved pathway is required, which might combine symptom-based criteria with the addition of a test to detect the presence of blood in the stool (similar to the test used in the national bowel screening programme). This approach has been enacted in the UK in order to better target colonoscopy resources and has been shown to outperform symptom-based criteria.

Article
SUMMARY

Improving early detection of colorectal cancer in Aotearoa New Zealand; how do the direct access criteria perform?

In New Zealand, patients with gastrointestinal symptoms can be referred for colonoscopy or other equivalent tests if they meet certain national criteria (which include an age range, symptoms such as the presence of blood in the stool, and whether the patient has a low red blood cell count caused by iron deficiency). Our study looked at all colonoscopy referrals to Christchurch Hospital through this referral pathway during the year 2018 to examine, amongst other outcomes, how the current criteria perform at detecting colon cancer. Of the 3,200 referrals, 128 patients were found to have colon cancer, which is only 4.0% of the referred patients. This can be thought of as the number of colonoscopies needing to be performed to detect one cancer being 25. Due to the pressure on colonoscopy resources in New Zealand, we argue that the current performance of the pathway is inadequate primarily due to the poor performance of a patient’s symptoms alone in determining colon cancer risk, and this leads to a large number of colonoscopies being performed with a low cancer “yield”. An improved pathway is required, which might combine symptom-based criteria with the addition of a test to detect the presence of blood in the stool (similar to the test used in the national bowel screening programme). This approach has been enacted in the UK in order to better target colonoscopy resources and has been shown to outperform symptom-based criteria.