21/11/2005.

Men who've been exposed to asbestos run a greater risk of developing colorectal cancer, according to US researchers. Dr Mark Cullen from Yale University School of Medicine and colleagues used data from a cancer prevention trial to investigate the risk of colorectal cancer among nearly 4,000 men. They compared a non-asbestos-exposed heavy-smoker subgroup of participants with an asbestos-exposed 'smoker-eligible' subgroup. Writing in the American Journal of Epidemiology, they say men in the asbestos-exposed group were 36 per cent more likely to develop colorectal cancer than were men in the heavy-smoker but not asbestos-exposed cohort. Participants with 21 to 30 years of exposure had a 74 per cent increased risk of colorectal cancer compared with those with less than 10 years of exposure.

• Oluremi A Aliyu, Mark R Cullen and others. Evidence for excess colorectal cancer incidence among asbestos-exposed men in the beta-carotene and retinol efficacy trial. American Journal of Epidemiology 162(9): 868-878 (2005) [abstract online]