Cancer of the bladder in Southern Iran.

The sex ratio for cancer of the bladder from hospitalized cases in Southern Iran is estimated to be about nine male per female cases. Differential case ascertainment may account for some of the discrepancy; however, no other major cancer site has a sex ratio of this nature, utilizing the same data. Since industrial carcinogens and other predisposing factors, such as schistosomiasis, are rare, the role of other possible etiologic factors, such as opium addiction, which is predominantly male, were considered and discussed.