[A hundred cases of multiple primary neoplasms in association with genitourinary cancer]

There were 970 patients who were diagnosed as having genitourinary cancer at Yamagata Prefectural Central Hospital between 1975 and 1990, and of whom 100 cases (10.3%) had multiple primary malignant neoplasms in addition to their genitourinary cancer. They were compared with 220 patients having single genitourinary cancer and 274 having benign prostatic hypertrophy without past histories of cancer. The genitourinary organs involved with cancers included the prostate (50 patients), urinary bladder (43 patients), ureter or renal pelvis (15 patients) and kidney (7 patients). In the prostate cancer, the incidental carcinomas occupied 30%. The other organs accompanying the genitourinary cancers included the stomach, lung and colon. In patients of multiple primary cancers, single genitourinary cancer and benign prostatic hypertrophy, positive family histories for cancer were observed in 40.0%, 37.7% and 33.2%, respectively, with no significant difference between these groups. Histories of smoking were observed in 54.0%, 38.2% and 34.3% respectively, with significant difference between the multiple primary neoplasm patients and the other 2 groups (p < 0.01). There were two cases in whom the second cancer could be possibly caused by the exposure to radiation for the first cancer. No oncotherapeutic drugs or occupational exposure could be seriously suspected of the cause of the second cancers in the present cases.