Multiple primary neoplasms in association with prostate cancer in black and white patients.

The current study follows up the 983 patients who were diagnosed as having prostate cancer at the Columbia-Presbyterian Medical Center in New York City between 1970 and 1979 and of whom 106 (11.5%) developed a multiple primary malignant neoplasm (MPMN) in addition to their prostate cancer by January 1, 1986. Of the 283 black patients, 32 (11.3%) developed an MPMN involving 35 sites excluding prostate. Of the 636 white patients, 74 (11.6%) developed an MPMN in association with their prostate cancer. Comparing observed incidence rates to expected on the basis of SEER incidence data, two malignant tumors, urinary bladder cancer and malignant lymphoma, appeared to occur in excess in the present series of patients. The excess of urinary bladder cancer in our series could be explained by detection bias due to the routine use of cystoscopy. The excess incidence of lymphoma in our series appears significant but its etiology is unexplained.