Several studies have suggested that men who had radiation therapy to treat prostate cancer
might have a higher risk of rectal cancer because the rectum receives some radiation during
treatment. Most of these studies are based on men treated in the 1980s and 1990s, and the
effect of more modern radiation methods on rectal cancer risk is not clear. There are many
possible side effects of prostate cancer treatment that men should consider when making
treatment decisions. Some doctors recommend that the risk of rectal cancer should be
considered as one of those possible side effects.