Evaluation of prognostic prediction ability of the novel Japanese risk factor scoring system in a Japanese cohort of resectable cutaneous squamous cell carcinoma: A retrospective cross-sectional study

Japanese patients with very high-risk cutaneous squamous cell carcinomas (cSCCs), based on the National Comprehensive Cancer Network guidelines, have been reported to display a higher cumulative incidence of relapse and disease-specific death (DSD) than those with high-risk cSCC. Therefore, prognosis prediction is crucial for Japanese patients with very high-risk cSCCs. Herein, we aimed to evaluate the prognostic prediction ability of our novel Japanese Risk Factor Scoring Systems (JARF scoring) in a Japanese cohort of cSSC patients. Data of 424 Japanese patients with resectable very high-risk cSCCs were analysed. We compared the prognostic ability of the following three staging systems: Brigham and Women's Hospital (BWH) tumour staging, number of NCCN very high-risk factors, and JARF scoring, including recurrent tumour, high-risk histological features, deep tumour invasion and lymphatic or vascular involvement as risk factors. The prognostic ability of these staging systems was evaluated according to the cumulative incidence of local recurrence (LR), regional lymph node metastasis (RLNM), DSD, and overall survival (OS). When BWH staging was used, high T stage led to significantly poor outcomes only in the cumulative incidence of RLNM (p = 0.01). The presence of very high-risk NCCN factors led to significantly poor outcomes in terms of RLNM (p = 0.03) and OS (p = 0.02). Meanwhile, a high number of risk factors in the JARF scoring system clearly led to poor outcomes in terms of LR (p = 0.01), RLNM (p < 0.01), DSD (p = 0.03), and OS (p < 0.01). The JARF scoring system may accurately predict the risk of recurrence and death in very high-risk cSCC patients in Japan.