riSCC: A personalized risk model for the development of poor outcomes in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (CSCC) is a prevalent disease for which improved risk stratification strategies are needed.

To develop a novel prognostic model (herein "riSCC") for CSCC and compare riSCC performance to Brigham and Women's Hospital and American Joint Committee on Cancer Staging eighth edition T staging systems.

Retrospective 12-center, multinational cohort study of CSCCs from 1991 to 2023. Clinical and pathologic risk factors, treatments, and outcomes were collected. Fine-Gray model was employed for each outcome with inverse probability of treatment weighting. A final model was trained for prospective use and estimation of hazard ratios.

Twenty-three thousand one hundred sixty-six localized CSCC tumors were included. riSCC prognostic model performed superiorly to American Joint Committee on Cancer eighth edition and Brigham and Women's Hospital T staging for all outcomes. At 5 years, the C-index for riSCC ranged from 0.74 for local recurrence to 0.87 for disease specific death.

Retrospective study design.

riSCC prognostic model offers fine-grained risk estimates and improved stratification for important CSCC outcomes compared to T staging systems.