Comparison of the American Joint Committee on Cancer Seventh Edition and Brigham and Women's Hospital Cutaneous Squamous Cell Carcinoma Tumor Staging in Immunosuppressed Patients.

Background: The American Joint Committee on Cancer 7th edition (AJCC-7) and Brigham and Women's Hospital (BWH) staging criteria for cutaneous squamous cell carcinoma (cSCC) have not been validated in immunosuppressed patients.

Objective: To compare the AJCC-7 and BWH staging systems for cSCCs in immunosuppressed patients.

Methods: A single-institution retrospective cohort study of cSCCs in immunosuppressed patients. Risks of local recurrence (LR), nodal metastasis (NM), in-transit metastasis, and any poor outcome (PO) were compared among AJCC-7 and BWH tumor T stages.

Results: One hundred six patients had 412 primary invasive cSCCs. Eighty-five percent were AJCC-7 T1, and 15% T2. Risks of NM and PO for AJCC-7 T1 versus T2 were 0.9% versus 5% and 12.8% versus 23.3%, respectively, p < .05. Eighty-one percent of tumors were BWH T1, 18% T2a, 1% T2b, and 0.2% T3. Risk of LR for BWH T1 versus T2a was 11.4% versus 20.3%, p < .01. Risk of NM increased from 0.3% for T1 to 4.1%, 25%, and 100% for T2a, T2b, and T3, p < .05. Ninety percent of PO occurred in low-stage BWH T1/T2a.

Conclusions: Low T-stage cSCCs account for most POs. Brigham and Women's Hospital staging criteria better risk stratifies cSCCs in immunosuppressed patients for risk of NM and LR.