SAN DIEGO—Prostate cancer patients who undergo radiation treatment, especially brachytherapy, are at increased relative risk of bladder cancer, new study findings presented at the American Urological Association 2016 annual meeting suggest. This increased relative risk occurs predominantly after 10 years.
Bladder tumors found in men following prostate radiotherapy are generally lower stage but higher grade than tumors found in patients without a history of prostate cancer, the study showed.
Aryeh Keehn, MD, and colleagues at Albert Einstein College of Medicine in Bronx, NY, analyzed data from the 1973–2011 Surveillance, Epidemiology and End Results database to ascertain the observed and expected number of bladder cancer cases after PCa radiotherapy. Bladder cancer developed in 6,401 of 346,429 men who underwent radiotherapy for PCa, which was 2.6 times the number of expected cases (2,464). All treatment modalities were associated with a higher relative risk of bladder cancer after 10 years, with the relative risk significantly higher following brachytherapy than after EBRT or EBRT plus brachytherapy.
Compared with men without a history of PCa, brachytherapy was associated with a 3.5-fold, 2.9-fold, and 5.5-fold increased risk of bladder cancer after 10 years in Caucasians, African Americans, and patients of other or unknown races, respectively, in adjusted analyses.