Prostate cancer patients who undergo radiation treatment, especially brachytherapy, are at increased relative risk of bladder cancer according to new study findings presented at the American Urological Association 2016 annual meeting by researchers from Albert Einstein College of Medicine in New York. 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. Compared with men without a history of prostate therapy, 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. Albert Einstein researchers arrived at their conclusion by analyzing data from the 1973–2011 Surveillance, Epidemiology and End Results (SEER) database to ascertain the observed and expected number of bladder cancer cases after prostate cancer radiotherapy. Radiation cystitis, often manifested years later, is another potential undesirable side effect of radiotherapy. For further details, see the following link.
Still another large cohort study published in the journal Cancer showed that the risk of colorectal cancer (CRC) is increased following a diagnosis of prostate cancer. This suggests CRC screening should be considered following a prostate cancer diagnosis, especially among those undergoing radiotherapy.