Risk factors for urinary bladder carcinoma in postmenopausal women. The Iowa Women's Health Study.

Abstract

We evaluated prospectively the association of smoking and other potential risk factors with bladder carcinoma incidence in postmenopausal women. A total of 37,459 women participating in the Iowa Women's Health Study completed baseline questionnaires in 1986 and were followed 13 years for bladder carcinoma incidence (n = 112). Adjusted for potential confounders, the relative risk (RR) of bladder carcinoma in women who were current smokers compared with those who had never smoked was 3.58 (95% confidence interval [CI] = 1.86-6.88). The RR declined as years since quitting increased. Currently, married women, compared with unmarried women, had a RR of 0.66 (95% CI = 0.44-0.99). A 2.46-fold (95% CI = 1.32-4.59) increase in bladder carcinoma risk was identified for women who reported, versus did not report, diabetes. Regular versus no physical activity (RR = 0.66, 95% CI 0.43-1.01) and body mass index were inversely associated (P = 0.06) with bladder carcinoma incidence. We confirmed that cigarette smoking is an important risk factor for bladder carcinoma in women; women who had quit smoking had a reduction of risk. We also identified diabetes as a potential risk factor, which may invite more research on its role in the development of urinary bladder carcinoma.