In this issue of JAMA Oncology, Cumberbatch and colleagues1 present a systematic review of the evidence of contemporary occupational exposure to carcinogens and bladder cancer incidence and mortality risk, as well as a meta-analysis of risk estimates.
Bladder cancer is the fourth most incident malignant neoplasm worldwide.2 In recent decades, incidence and mortality rates in general have decreased in most Western countries but increased in some eastern European and developing countries.2 In the United States both incidence and mortality rates have been stable since the 1970s.3 These patterns reflect differences on tobacco use, which is estimated to account for 50% of all cases in Europe,4 as well as occupational exposures, which are the second most common etiological factors. Men are more affected than women both for bladder cancer incidence and mortality, likely owing to more smoking and occupational exposure to carcinogens among men. In countries where incidence trends are increasing, in general, rates in women are increasing more than those among men.2 This may be due to the increase in female work force in recent decades or to exposure of female workers to bladder carcinogens not yet fully identified.