Identifying Brigham and Women's Hospital stage T2a cutaneous squamous cell carcinomas at risk of poor outcomes

Abstract

Background: Although most of the poor outcomes with cutaneous squamous cell carcinoma (CSCC) occur in high-stage tumors, 26% of nodal metastases and 8% of disease-specific deaths develop in Brigham and Women's Hospital (BWH) T2a tumors.

Objective: To determine risk factors associated with poor outcomes (nodal metastasis, distant metastases, and disease-specific deaths) in BWH T2a CSCC.

Methods: A 17-year retrospective multi-institutional cohort study of primary CSCC BWH T2a tumors. A predictive model based on tumor characteristics was developed to identify those at higher risk of poor outcomes.

Results: Presence of 1 major criterion (primary tumor diameter ≥40 mm, invasion depth beyond subcutaneous fat, poor differentiation, or large-caliber perineural invasion) and ≥ 1 minor criterion (invasion depth in subcutaneous fat, moderate differentiation, small-caliber perineural invasion, or lymphovascular invasion) was most predictive of developing poor outcomes (area under the curve, 0.53; C-statistic, 0.60). This model has a sensitivity of 7.7%, specificity of 97.4%, and a positive and negative predictive value of 33.3% and 86.1%, respectively. The 5-year cumulative incidence of poor outcomes in these tumors is 8.0% (95% CI, 5.1-13.7) compared to 2.8% (95% CI, 1.9-4.1) in other T2a tumors (sub-hazard ratio, 3.0; 95% CI, 1.5-5.8).

Limitations: Multi-institutional cohort study was not externally validated.

Conclusions: BWH T2a-high CSCCs have an 8% chance of developing poor outcomes.

Keywords: cutaneous squamous cell carcinoma; disease-specific death; distant metastasis; nodal metastasis.