Keratinocyte carcinomas in survivors of childhood cancer: A report from the childhood cancer survivor study.

Abstract

Childhood cancer survivors (CCS) are at increased risk for keratinocyte carcinomas (KC) however, the long-term incidence of single and multiple KC is not well established. Identify risk factors and quantify KC cumulative incidence and multiple-incidence burden in CCS. KC were identified among Childhood Cancer Survivor Study participants, a cohort of 5-year cancer survivors diagnosed <21 years of age between 1970 and 1999 in North America. Cumulative incidence was estimated and multivariable models assessed relative rates of KC associated with survivor and treatment characteristics. Among 25,658 participants, 1446 developed 5363 KC (93.5% basal cell carcinoma, 6.7% squamous cell carcinoma; mean age 37.0 years (range 7.3-67.4), mean latency 25.7 years; 95.3% White and 88.4% with radiotherapy). Mean lesion count was 3.7 with 26.1% experiencing ≥4. Radiotherapy imparted a 4.5-fold increase in the rate of any KC and 9.4-fold increase in the rate of ≥4 KC. Allogeneic and autologous hematopoietic cell transplant were associated with a 3.4- and 2.3-fold increased rate of KC, respectively. Participant self-reporting of some data including race without skin phototype and past medical history may have impacted analysis. The burden of KC in CCS remains high, but predictable risk factors should guide screening.