Non-Melanoma Skin Cancer Event Rates: Considerations for Clinical Trial Design

According to a study published in the European Journal of Cancer Prevention, a history of non-melanoma skin cancer (NMSC) and the frequency of prior tumors are important predictors of future NMSC risk.

Researchers investigated clinical risk factors and event rates for the development of new NMSC in a randomized, double-blind, placebo-controlled trial. The trial focused on evaluating the irreversible ornithine decarboxylase (ODC) inhibitor difluoromethylornithine over a follow-up period of 3 to 5 years. The analysis involved 147 White participants with a mean age of 60.2 years, 60% of whom were male, all of whom were on placebo.

Over a median follow-up of 4.4 years, several factors were found to be significant predictors of new NMSC development. Key predictors included a history of prior NMSCs, basal cell carcinomas (BCCs), squamous cell carcinomas (SCCs), and the rate of prior tumors. Specifically, prior occurrences of NMSCs, BCCs, and SCCs were strongly associated with the development of new BCCs and SCCs, with statistical significance across multiple measures. Additional predictors for new NMSC development included age, hemoglobin levels, and gender.

Interestingly, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ODC activity at baseline did not show a statistically significant association with the development of new NMSCs, BCCs, or SCCs. This suggests that while TPA-induced ODC activity may not be a reliable predictor, the history of previous skin cancers and the rate at which they occur are critical factors to consider in assessing the risk for new NMSC development.

The study concluded that a history of NMSCs and the frequency of prior tumors are important predictors of future NMSC risk and should be considered in the design and control of future NMSC prevention trials.

Reference
Lozar T, Kim K, Havighurst TC, Wood GS, Kolesar JM, Bailey HH. Non-melanoma skin cancer event rates in a formalized clinical trial setting: considerations for clinical trial design. Eur J Cancer Prev. 2024;33(1):69-72. doi:10.1097/CEJ.0000000000000829