Colorectal cancer incidence and trend in UK South Asians: a 20-year study

Abstract

South Asians comprise 13.6% of the Wolverhampton population. We aimed to compare the incidence and trend of colorectal cancer in this subgroup with the non South Asian population over a 20-year period. Patients of South Asian origin diagnosed with colorectal cancer from 1989 to 2008 were identified from the hospital histopathology database and compared with those of non South Asian origin. 1991 and 2001 census data were used to standardize for differing age and sex distributions in the two study populations. The median unadjusted incidence of colorectal cancer from 1989 to 2008 was 6.17 per 100,000 per year in South Asians compared with 71.70 per 100,000 per year in non South Asians (77.79% white British). The age and sex adjusted odds ratio for colorectal cancer in South Asians was 0.2 (P < 0.001). There was an equal increased trend in the incidence in both the South Asians and non South Asians over the study period (0.8% per year). In patients < 50 years, the gender difference in the incidence of cancer was not significant, but as age increased this rose significantly (males > females). There was a markedly lower incidence of colorectal cancer in South Asians compared with non South Asians, maintained over 20 years. Colorectal cancer incidence increased by a small and similar amount over the period in both groups. There was a male preponderance of colorectal cancer in both populations over 50 years.