The risk of bladder cancer in patients diagnosed with other primary neoplasms: Analysis of the SEER database

Objective: We evaluated patients with history of previous malignancy to determine risk of an ensuing bladder cancer. Materials and methods: The National Cancer Institute's Surveillance, Epidemiology, and End Results 9 registry database from 1973 to 1999 (SEER) was reviewed for patients with initial primary cancers in oral cavity and pharynx, colon and rectum, respiratory system, breast, prostate, testis, or penis. This group of patients was then examined to identify subsequent separate primary malignancies in the bladder. Comparison was made to the incidence of bladder cancer in the general population to determine a standardized incidence ratio (SIR). Additional analysis was performed based on age at diagnosis, stage, gender, race, and use of external beam radiation for treatment of initial cancer. Results: A total of 7,289 (0.5%) of patients had a bladder cancer following their initial malignancy. Patients with prostate cancer had the largest increase in risk of bladder cancer with a SIR of 8.24, and all initial cancer groups had an elevated risk of bladder cancer relative to the general population. External beam radiation and non-White gender were associated with an increased risk of bladder cancer. Older age at diagnosis of the initial cancer correlated with a lower risk of subsequent bladder cancer. Conclusions: This study suggests an increased risk of bladder cancer following a separate initial cancer. Lower threshold for working up those patients for bladder cancer may be warranted.