Dalwadi SM, et al. - Researchers examined the risk of second primary thyroid cancer (SPTC) following radiation therapy exposure (XRTe) across all ages or stratified by histological subtypes. In this database study, they determined patient characteristics of a Surveillance, Epidemiology, and End Results dataset of SPTC (n = 4,669) using χ² and t-tests. Based on XRTe, similar extrathyroid extension and node status were observed. XRTe patients more frequently have smaller tumors (17.6 vs 19.3 mm). Diagnosis with SPTC was made at younger ages among XRTe patients (59.8 vs 62.7 years) without a difference in latent survival (time from the initial diagnosis to SPTC; 7.45 vs 7.50 years). A higher risk of SPTC after XRTe was noted among patients aged 1 to 29 years at diagnosis of first cancer. No increased risk of SPTC was noted among patients aged 30+ years receiving radiation therapy (XRT). To reduce the risk of subsequent malignancy in younger patients, deliberation is important in recommending, planning, and delivering XRT.