Although survivors of HL comprised only 13.4% of the cohort, they experienced 33.8% of the reported SMNs and 37.9% of the NMSCs. For the SMNs, this is largely driven by breast cancer, with 94 (59.9%) of 157 second breast cancers in the CCSS occurring in HL survivors. This finding is consistent with reports by others.28,29 However, the significant proportion of NMSC among HL survivors has not been previously reported. As this study's cohort was derived from patients surviving 5 years or more, it is not surprising that leukemia was not a common SMN and occurred in only 43 individuals.