Nijhawan, Rajiv I.

ABSTRACT Background Current staging systems for head and neck cutaneous squamous cell carcinoma (HNCSCC), such as AJCC8 and BWH, often fail to adequately stratify high‐risk patients, particularly due to the exclusion of important biological and host factors. This study aimed to identify independent prognostic factors for HNCSCC outcomes in the largest multi‐institutional retrospective series to date. Methods De‐identified data from 8,610 primary HNCSCC tumors, treated with curative intent surgery across multiple international centers, were analyzed. Outcomes included local recurrence (LR), locoregional metastasis (LM), distant metastasis (DM), and disease‐specific death (DSD). Multivariable Fine–Gray subdistribution hazard regression models with robust standard errors clustered at the patient level were fitted to generate exploratory hypotheses regarding independent hazard determinants. Results During a median follow‐up of 31.4 months (IQR 14.2–52.8), the cumulative incidence was 3.3% for LR, 2.7% for LM, 0.5% for DM, and 1.2% for DSD. Multivariable analysis confirmed that tumor diameter, poor differentiation, deep invasion, and large‐caliber perineural invasion (LCPNI) were the strongest predictors, being significantly associated with at least three of the four outcomes. Notably, factors currently excluded from or weighted differently in staging systems also proved critical: Immunosuppression was significantly associated with LR (SHR 2.03) and DSD (SHR 1.70); and lymphovascular invasion (LVI) was independently associated with LM (SHR 3.00). Poor differentiation demonstrated high prognostic impact, being a significant predictor for all four endpoints. Conclusion Tumor diameter, poor differentiation, deep invasion, LCPNI, immunosuppression status, and LVI are the most critical independent factors for HNCSCC prognosis. Our multi‐institutional data provide a robust framework for hypothesis generation, highlighting that incorporating host biological features and non‐anatomic variables could significantly refine future staging system discussions.

BACKGROUND The use of Mohs micrographic surgery as a treatment for melanoma is rising, but the reliability of Mohs surgeons in assessing MART-1 melanoma en-face margins has not been evaluated. OBJECTIVE To evaluate interrater and intrarater reliability of Mohs surgeons in interpreting margins of early-stage melanoma. METHODS Twenty Mohs surgeons were asked to independently review images of frozen section MART-1 en-face peripheral margins of in situ or early-stage melanoma. Surgeons determined margins as positive or negative at initial evaluation and 6 weeks later. Primary outcomes were interrater and intrarater reliability. RESULTS Interrater agreement was 84.1% (95% confidence interval [CI]: 75.5%–92.8%) for assessment 1 and 87.5% (95% CI: 78.4%–96.4%) for assessment 2, with kappa values 0.68 (95% CI: 0.50–0.82) and 0.75 (95% CI: 0.57–0.88). Average intrarater percent agreement was 95.0% (95% CI: 70.6%–100.0%) with average kappa 0.90 (95% CI: 0.50–1.00). CONCLUSION Substantial interrater and nearly perfect intrarater agreement was identified among surgeons assessing melanoma margins utilizing MART-1 immunostaining, demonstrating consistent and reproducible assessment of melanoma margins during Mohs cases.

ABSTRACT Importance Risk stratification of cutaneous squamous cell carcinoma (CSCC) is central to effective management. Despite advancements in the 8th edition of the American Joint Committee on Cancer (AJCC8) staging system, the distinctiveness of T‐stages remains limited. Objective To evaluate the effectiveness of the Brigham and Women's Hospital (BWH) and the AJCC8 staging systems in predicting poor outcomes in head and neck (HN) CSCC. Design A retrospective, multinational cohort study of CSCCs diagnosed between January 10, 1991, and December 31, 2023. Setting Twelve centers across the United States (10), Spain (1), and Brazil (1). Participants Patients with invasive CSCC who underwent curative‐intent surgical treatment. Exclusions included cases of lip CSCC, cases with prior HN cancer with associated regional disease, patients with a history of chemotherapy/radiotherapy for other HN neoplasms, and recurrent primary tumors. Exposure Tumors were staged according to both the AJCC8 TNM staging system and the BWH tumor classification. Main Outcomes and Measures Local recurrence (LR), nodal recurrence (NR), distant recurrence (DR), and disease‐specific death (DSD). Results A total of 9852 excised tumors from 3168 patients were included. The 2 systems had comparable monotonicity and homogeneity. Significant differences could be observed in 5‐year cumulative incidence for DSD in both BWH and AJCC8, and also for LR in BWH. Higher T‐stages exhibited similar curves regarding NR and DR for both AJCC8 and BWH staging systems. Overall, we observed high specificity and NPV, low sensitivity and PPV, and moderately high c‐indices for both the BWH and AJCC8 staging systems in predicting the main outcomes for HNCSCC. Conclusion and Relevance Current AJCC8 and BWH staging systems can accurately predict survival in HNCSCC, although there are still important characteristics to be addressed in future staging systems for better stratification according to the other main outcomes.

BACKGROUND Mohs micrographic surgery (MMS) for cutaneous melanoma is becoming more prevalent, but surgical technique varies. OBJECTIVE To define variations in published techniques for MMS for melanoma. METHODS AND MATERIALS A systematic review was performed of PubMed, EMBASE, and Scopus databases to identify all articles describing surgical techniques for MMS for melanoma. Technical details were recorded for the preoperative, intraoperative, and postoperative phases of MMS. RESULTS Twenty-four articles were included. Mohs surgeons vary in how they assess clinical margins, how wide a margin they excise on the first MMS layer, and how they process tissue to determine tumor stage and margin clearance during MMS for melanoma. CONCLUSION Mohs micrographic surgery for melanoma is performed with varied surgical techniques. To establish best practices, additional research is necessary to determine how different techniques affect outcomes.