Jambusaria‐Pahlajani, Anokhi

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.

Importance There is no consensus on staging and surveillance imaging for cutaneous squamous cell carcinoma (CSCC). Although imaging has been shown to affect management, broad recommendations from the National Comprehensive Cancer Network have led to variability in clinical practice. Objective To develop multidisciplinary consensus recommendations on the use of staging and surveillance imaging of localized CSCC. Evidence Review A multidisciplinary expert panel across academic and clinical practice settings convened a Delphi consensus, with 3 iterative survey rounds from January to June 2025. Data were analyzed from February 2025 to January 2026. Eligibility defined by at least 1 to 2 CSCC publications during the previous 5 years, involvement in a relevant clinical trial, experience treating at least 3 patients monthly with CSCC, and/or 5 years or longer of clinical practice. Fifty-four experts were invited and 45 (83%) completed all 3 rounds and were included in the final analysis. Structured Delphi surveys evaluated clinical scenarios, imaging modalities, and surveillance strategies for CSCC. Consensus and near-consensus recommendations were generated, defined as 80% or greater and 70% to 79% agreement, respectively. Findings The 45 participants (21 female individuals [47%] and 24 male individuals [53%]; 14 Asian individuals [31%], 1 multiracial individual [2%], and 30 White individuals [67%]) consisted of dermatology (15 [33%]), medical oncology (7 [16%]), radiation oncology (9 [20%]), radiology (9 [20%]), surgery (3 [7%]), and otolaryngology specialists (2 [4%]). The Delphi panel recommended staging and surveillance for CSCCs with at least a 15% risk of metastasis. Consensus or near consensus was reached to recommend staging and surveillance imaging for tumors with a concern for metastasis, bone invasion, invasion beyond subcutaneous fat, large-caliber nerve invasion, or a diameter of 4 cm or larger or the combination of tumors with poorly differentiated histology and any of the following: diameter of 2 cm or larger, lymphovascular invasion and subcutaneous fat invasion, or lymphovascular invasion and small-caliber perineural invasion. Computed tomography imaging was the preferred modality for nodal staging (38 [84%]) and surveillance (35 [78%]). For surveillance duration, consensus was reached to provide imaging for at least 2 years, and near consensus was reached for at least 3 years. Conclusions and Relevance This study provides an expert consensus–based framework to standardize imaging in localized CSCC that may inform future guidelines.

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.

ImportanceCutaneous squamous cell carcinoma (CSCC) is the second most common malignant disease in the US. Although it typically carries a good prognosis, a subset of CSCCs are highly aggressive, carrying regional and distant metastatic potential. Due to its high incidence, this aggressive subset is responsible for considerable mortality, with an overall annual mortality estimated to equal or even surpass melanoma. Despite this morbidity, CSCC is excluded from national cancer registries, making it difficult to study its epidemiology and outcomes. Therefore, the bulk of the CSCC literature is composed of single-center and multi-institutional retrospective cohort analyses. Given variations in reporting measures and analyses in these studies, interpretability between studies and the ability to pool results are limited.ObjectiveTo define standardized reporting measures for retrospective CSCC studies.FindingsAn expert panel was convened to determine standardized guidelines for recording and analyzing retrospective CSCC data. A total of 13 dermatologists and dermatologic surgeons with more than 5 years of posttraining experience and considerable experience with performing CSCC outcomes research were recruited to the panel. Consensus recommendations were achieved for CSCC retrospective study reporting measures, definitions, and analyses.Conclusions and RelevanceThe recommendations in this report present the potential to standardize future CSCC retrospective studies. With such standardization, future work may have greater interstudy interpretability and allow for pooled analyses.

Checkpoint blockade inhibitors have revolutionized the treatment of metastatic melanoma. Despite the success of these agents in improving the overall survival of patients with metastatic melanoma, not all patients achieve clinical benefit, leaving room for improvement. The presence of cutaneous metastases in patients with metastatic melanoma provides the unique opportunity to treat the cutaneous lesions with a local modality while simultaneously treating systemic disease with systemic therapy. Herein, we describe the treatment of two patients with both in-transit and metastatic melanoma with the combination of the topical toll-like receptor 7 agonist imiquimod with systemic ipilimumab. Both patients appeared to have progressed and developed new cutaneous and systemic metastases while on single agent ipilimumab only to respond when started on topical imiquimod. Both patients tolerated the combination of imiquimod and ipilimumab without serious adverse events, and both patients had excellent clinical responses. These cases provide a proof of principle of the possibility of the combination of toll-like receptor 7 agonists with immune checkpoint blockade inhibitors.