Bladder cancer following prostate cancer--an analysis of risk factors.

Between 1969 and 1988, 1421 men had been treated for primary adenocarcinoma of the prostate. In 14 cases subsequent primary bladder cancer was observed, as compared to 5.98 cases to be expected, thus constituting a relative risk of 2.34. Seven of these cases developed synchronously (within 6 months), with a range of up to 10 years. Aetiologically, cigarette smoking was detected as the single most important denominator, whereas family history was positive for malignancy in only two cases.