Background and aims: The literature on colorectal cancer (CRC) screening and ethnic diversity is dominated by studies from the USA. There are no such published data from the UK bowel cancer screening programme (BCSP) population. The Wolverhampton Bowel Cancer Screening Centre serves a population of 900,000 in the Black Country and South Staffordshire. South Asians (SA) comprise 9% of the population. We aimed to determine the effects of ethnicity and sex on the risk for cancer or adenoma detected by colonoscopy following a positive faecal occult blood test over a 5-year period (2007-2011).
Methods: Data were collected from the prospectively maintained BCSP cohort. South Asian patients were identified and compared with those of non-South Asian ethnicity, and colonoscopy outcomes were determined.
Results: A total of 3552 participants underwent BCSP colonoscopy (non-South Asian=3363; SA=189). There were 271 cancers (7.6%) detected within the non-South Asian group and seven cancers (0.2%) in the South Asian population (P<0.05). The probability of colon cancer is higher [odds ratio (OR)=3.84, P<0.05] in non-South Asians compared with South Asians. Patients in the 65-70-year age group have the highest risk (OR=1.60; P<0.05) for CRC. During the study 1313 adenomas were detected. A total of 771 high-risk and intermediate-risk adenomas were detected in the non-South Asian group, and 14 were detected in the South Asian group. The risk of adenoma in non-South Asians is six times higher than in South Asians (OR=5.99, P<0.001) following positive faecal occult blood testing.
Conclusion: There are fewer colorectal cancers in South Asians compared with the non-South Asian population in this regional study. This is the first such study in the BCSP population.