Immune Checkpoint Inhibitors in Field Cancerization and Keratinocyte Cancer Prevention.

Area of Science:

• Dermatology
• Oncology
• Immunology

Background:

• Therapies for individual keratinocyte carcinomas (KCs) do not prevent new KC development in sun-damaged skin.
• Field cancerization, characterized by actinic keratoses (AKs) and KCs, poses a persistent challenge in skin cancer management.

Purpose of the Study:

• To investigate the association between immune checkpoint inhibitors (ICIs) and changes in field cancerization.
• To evaluate the impact of ICIs on the number of AKs and KCs over 12 months.

Main Methods:

• A prospective cohort study involving 23 immunocompetent adults receiving ICI therapy (PD-1/PD-L1 inhibitors).
• AKs were counted and photographed at baseline and 3, 6, and 12 months.
• KC numbers were assessed via histopathology reports from the 12 months before and after ICI initiation.

Main Results:

• A significant decrease in mean AKs from 47.2 at baseline to 14.3 at 12 months (P < .001).
• Total KC numbers reduced from 42 to 17, with cutaneous squamous cell carcinomas decreasing from 16 to 5.
• Younger patients and those with a history of sunburn were more likely to achieve a significant AK reduction.

Conclusions:

• ICIs demonstrated a significant reduction in AKs, indicating potential as an immunopreventive strategy for high-risk individuals.
• Further research is warranted to explore ICIs for managing field cancerization, considering their efficacy, toxicity, and cost.