Effects of Radiation Therapy on the Incidence of Bladder Cancer and Rectal Cancer in Patients with Prostate Cancer: A Nationwide Nested Case-Control Study in Korean Population

Purpose

This study aimed to assess the risk of secondary bladder and colorectal cancers following radiotherapy for prostate cancer using a nationwide nested case-control design based on Korea’s Health Insurance Review and Assessment database. Materials and Methods: We conducted a nationwide nested case-control study using database, including men newly diagnosed with prostate cancer between 2011 and 2020. Patients were classified into radiotherapy and non-radiotherapy groups and matched 1:1 based on age, comorbidity index, and follow-up duration. Conditional logistic regression was used to assess the association between radiotherapy and secondary bladder and colorectal cancer incidences.