LAUSR

Key Points Question Do patients with prostate cancer in the modern era have a higher incidence and risk of developing a second primary cancer after radiotherapy compared with nonradiotherapy treatments? Findings In this cohort study of 143 886 patients with localized prostate cancer, receipt of radiotherapy was associated with a small but statistically significant increase in the risk of developing a second primary cancer. Meaning This study’s findings suggest that it is important that shared decision-making among patients with prostate cancer includes discussion of late toxic effects, including the risk of developing a second primary cancer, and that the possibility of developing a second primary cancer after radiotherapy be considered during evaluation of symptoms among survivors.