MULTIPLE PRIMARY MALIGNANCIES IN RENAL-CELL CARCINOMA

Purpose: We determine the incidence and nature of multiple primary mal ignancies in patients with renal cell carcinoma, and whether these pat ients have an increased risk of a second primary malignancy. Materials and Methods: Between July 1989 and January 1997, 551 patients underwe nt an operation for renal cell carcinoma. The incidence of other prima ry malignancies was determined and classified as antecedent, synchrono us or subsequent. The observed number of subsequent malignancies after diagnosis of renal cell carcinoma was compared to the expected number based on age, race and sex specific 1990 to 1994 incidence rates from the United States Surveillance, Epidemiology and End Results data usi ng the Poisson test. Results: The number of primary malignancies, incl uding cutaneous malignancies, was at least 1 in 148 patients (26.9%), at least 2 in 34 (6.2%), at least 3 in 6 (1.1%) and 4 in 1 (0.2%). Oth er malignancies were antecedent in 85 cases (45.0%), synchronous in 74 (39.4%) and subsequent in 30 (16.0%). The most common other primary m alignancies were breast, prostate, colorectal and bladder cancer, and nonHodgkin's lymphoma. Only men with renal cell carcinoma had an incre ased risk of bladder cancer (standardized incidence ratio 4.3, p = 0.0 067). CConclusions: Breast, prostate, colorectal and bladder cancer as well as nonHodgkin's lymphoma were the most common other primary mali gnancies. Men with renal cell carcinoma have an increased risk of subs equent bladder cancer.