Bladder Cancer Risks Increase Over Time For Smokers

Extract

Risk of bladder cancer for smokers has increased since the mid-1990s, with a risk progressively increasing to a level five times higher among current smokers in New Hampshire than that among nonsmokers in 2001-2004, according to a new study published online November 16 in the Journal of the National Cancer Institute. Furthermore, researchers found that among individuals who smoked the same total number of cigarettes over their lifetime, smoking fewer cigarettes per day for more years may be more harmful than smoking more cigarettes per day for fewer years.

It is well known that cigarette smoking causes bladder cancer, but the influence of various parameters of smoking history, including trends in risk over time, is unclear.

Dalsu Baris, M.D., Ph.D., of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, in Bethesda, Md., and her colleagues from NCI, Dartmouth Medical School, and the departments of health for the states of Maine, New Hampshire and Vermont, examined bladder cancer risk in relation to smoking practices based on data from a large, population-based case–control study conducted in Maine, New Hampshire, and Vermont from 2001 to 2004. To examine changes in smoking-induced bladder cancer risk over time, the researchers compared odds ratios for New Hampshire residents in this study with those from two, case–control studies conducted in New Hampshire by Margaret Karagas, Ph.D., of Dartmouth Medical School in 1994–1998 and in 1998–2001.