Survival of Childhood Cancer and Subsequent Clinical Care—Reply

In Reply Dr Boull and colleagues raise important points in their Letter. Our recent Review noted the absence of randomized clinical trials testing the efficacy of the Children’s Oncology Group Long-Term Follow-Up Guidelines (COG LTFU Guidelines) in mitigating the risk of adverse treatment-related outcomes. The lack of randomized clinical trials is not limited to skin cancer but applies to all recommendations within the COG LTFU Guidelines. Given the relatively small absolute numbers of childhood cancer survivors who experience specific adverse outcomes, and the long latency of complications, the plausibility of obtaining such randomized trial data is low. This is the rationale for establishing the modality and intensity of screening recommendations within the COG LTFU Guidelines on expert consensus, although the populations at risk for these recommendations are based on the associations between therapeutic exposures and adverse late outcomes and are evidence based. Thus, we believe that the skin cancer screening recommendations outlined in the COG LTFU Guidelines, which Boull and colleagues have nicely summarized, should be performed as recommended due to the substantial risk that childhood cancer survivors have of developing subsequent skin cancers. But we again qualify that there are no randomized clinical trials that provide level 1 evidence regarding the efficacy of these recommendations.