Comparison of Tumor Staging Systems for Cutaneous Squamous Cell Carcinoma in Patients with Chronic Lymphocytic Leukemia

Abstract Background Patients with chronic lymphocytic leukemia (CLL) are at increased risk for poor outcomes as a result of cutaneous squamous cell carcinoma (CSCC). Objective To compare the relative effectiveness of tumor staging systems for CSCC in a well-defined cohort of patients with CLL. Methods This retrospective outcomes study included 454 CSCC tumors among 161 patients with underlying CLL evaluated at a single academic medical center. Each tumor was staged according to Brigham and Women’s Hospital (BWH), Union for International Cancer Control Eighth Edition (UICC8), and American Joint Committee on Cancer Seventh and Eighth Edition criteria (AJCC7, AJCC8). We compared the effectiveness of tumor risk stratification by each system. Results The BWH tumor staging system demonstrated superior risk stratification relative to AJCC7 criteria (C-index 0.725 vs 0.615, p-value 0.036) and trended toward improved stratification relative to the AJCC8 (C-index 0.796 vs. 0.732, p-value 0.214) and UICC8 (C-index 0.725 vs 0.636, p-value 0.096) staging systems. Limitations Our study must be interpreted in the context of its retrospective design and relatively small number of adverse outcomes available for statistical analysis. Conclusions and Relevance: The BWH system outperformed AJCC7 criteria and trended toward superior risk stratification relative to both AJCC8 and UICC8 criteria.