Smoking link may explain anti-bladder cancer effects of vitamins

A few reports have suggested that certain vitamins protect against bladder cancer. However, new study findings indicate that the apparent anti-cancer effect disappears after accounting for smoking history.

The results, which are published in the October issue of The Journal of Urology, are based on a study of 9345 men who had serum samples frozen at baseline and then were followed for more than 20 years to determine the rate of bladder cancer. During the study period, 111 men developed bladder cancer. The stored serum samples from these men and from 111 matched controls were analyzed for levels of several vitamins. Dr. Abraham M. Y. Nomura, from Kuakini Medical Center in Honolulu, and colleagues found that serum levels of alpha-carotene, beta-carotene, lutein plus zeaxanthin, beta-cryptoxanthin, and total carotenoids were inversely related to the risk of bladder cancer. However, after accounting for pack-years of cigarette smoking, none of the vitamin levels were significantly related to bladder cancer risk, the authors point out.”These results suggest that cigarette smoking, which is a strong risk factor for bladder cancer, may explain the apparent protective effect of individual and total carotenoids against this common cancer,” they conclude.(Source: J Urol 2003;170:1146-1150: Reuters Health: October 10, 2003: Oncolink)