Risk of bladder cancer by geographic region in a US cohort of male health professionals

Large regional variations in bladder cancer rates have been observed for nu merous decades in the United States and persist to date. We examined the in cidence rates of bladder cancer by geographic region among U.S. male health professionals to determine whether diet or other lifestyle factors can acc ount for variations observed. During 12 years of follow-up, 328 cases of bl adder cancer were diagnosed in the Health Professionals Follow-up Study Coh ort. We inquired about diet, lifetime history of smoking, race, marital sta tus, and other nondietary factors using mailed questionnaires. An elevated risk of bladder cancer was observed in the Northeast compared with the West [relative risk (RR) = 1.71, 95% confidence interval (Cl) = 1.23-2.39], whi ch was slightly attenuated after controlling for smoking (RR = 1.65, 95% CI = 1.18-2.30). Smoking patterns, diet, and other lifestyle factors could no t account for all of the elevated bladder cancer risk in the Northeast, Bla dder cancer risk was highest among men who had a long residency in the Nort heast compared with a long residency in the West (RR = 1.77, 95% CI = 1.15- 2.71, adjusted for smoking). Diet and other known characteristics do not ap pear to be responsible for the regional variations in bladder cancer rates in the United States.