In Reply We appreciate the letter by Verkouteren et al, which challenges our specialty to think about rigorous methodological issues. We agree that death is a competing risk, as it is in every survival analysis, and that overestimation is a possibility when using standard Kaplan-Meier analyses. Competing risks analysis using a cumulative incidence curve (CIC) may give a lower estimate than Kaplan-Meier, especially when death is a frequent outcome.
The goal of our article was to examine the timing and pattern of multiple subsequent new keratinocyte cancers (KCs) to determine whether follow-up care of patients with skin cancer can be improved. Prior analyses had focused on the first subsequent KC and did not account for multiple subsequent tumors (eg, third, fourth, fifth tumors). Our study was a novel way to characterize and quantify the way individual patients develop multiple KCs over time. While we were aware of CICs and competing risks of death as a potential limitation, because our primary analysis was complex and required multiple event survival analysis, we chose to use Kaplan-Meier survival analysis rather than include competing risks in our analyses.
Wehner MR, Linos E, Boscardin WJ, Chren M. Competing Risk of Death in Kaplan-Meier Curves When Analyzing Subsequent Keratinocyte Cancer—Reply. JAMA Dermatol. 2016;152(4):494-495. doi:10.1001/jamadermatol.2015.5153