Tracking the risk factors associated with high-risk cSCC: A 10-year, Two-Institution, Greek study.

Purpose: We sought to identify independent risk factors for positive sentinel lymph node biopsy (SLNB), local recurrence (LR), metastasis (M) and death caused by cutaneous squamous cell carcinoma (cSCC) (DCS) in high-risk cSCC patients. Moreover, we compared the Brigham and Women's Hospital (BWH) system with the previous used in Greece (based on tumor size) and proposed a new classification system.

Methods: 1,524 cSCC patients were enrolled between January 2004 and December 2014, from two medical institutions. Potential risk factors for SLNB (local recurrence/LR, metastasis/M, death caused by SCC/DCS) were analyzed by univariate and multivariate Cox logistic regression models.

Results: Of the included patients with a median follow-up of 60 months 107 developed local recurrence (7%) while 84 developed metastases (5.5%). Among 36 patients undergoing sentinel lymph node biopsy (SLNB), 25% showed a positive SLNB with a false-negative result (11%). On multivariate analysis, key prognostic factors for LR were tumor diameter ≥2 cm, poor differentiation, incomplete excision and perineural invasion and for M were high-risk tumor site, tumor diameter ≥2 cm, poor differentiation, invasion beyond subcutaneous tissue, incomplete excision, perineural invasion and recurrence. DCS seems to be affected by tumor diameter ≥ 2 cm, poor differentiation, invasion beyond subcutaneous tissue, incomplete excision, perineural invasion and recurrence independently.

Conclusions: These suggest the determined role of tumor diameter of cSCCs. Harnessing knowledge and collecting the up-to-date data along the clinical journey of high-risk cSCC, the future looks bright (development of new clinical trials, adjuvant therapies and tumor staging with SLNB).