Validation of the 2022 National Comprehensive Cancer Network Risk Stratification for Cutaneous Squamous Cell Carcinoma.

Importance: The 2022 National Comprehensive Cancer Network (NCCN) reclassified cutaneous squamous cell carcinoma (CSCC) into low-, high-, and very high-risk groups to better risk stratify tumors. Mohs micrographic surgery (Mohs) or peripheral and deep en face margin assessment (PDEMA) became preferred surgical modalities for high- and very high-risk tumors. This new risk stratification and the recommendation for Mohs or PDEMA in high- and very high-risk groups have not been validated. Objective: To compare outcomes in very high-, high-, and low-risk NCCN groups of CSCCs and in CSCCs treated with Mohs or PDEMA compared with wide local excision (WLE). Design, Setting, and Participants: This retrospective cohort study of CSCCs was performed in 2 tertiary care academic medical centers. Patients 18 years or older and diagnosed between January 1, 1996, and December 31, 2019, at Brigham and Women's Hospital and Cleveland Clinic Foundation were included. Data were analyzed from October 20, 2021, to March 29, 2023. Exposures: NCCN risk group, Mohs or PDEMA, and WLE. Main Outcomes and Measures: Local recurrence (LR), nodal metastasis (NM), distant metastasis (DM), and disease-specific death (DSD). Results: A total of 10 196 tumors from 8727 patients were stratified by NCCN guidelines into low-, high-, and very high-risk groups (6003 [59.0%] men; mean [SD] age, 72.4 [11.8] years). Compared with the low-risk group, the high- and very high-risk groups demonstrated a greater risk of LR (high-risk subhazard ratio [SHR], 1.99 [95% CI, 1.21-3.27; P = .007]; very high-risk SHR, 12.66 [95% CI, 7.86-20.39; P < .001]), NM (high-risk SHR, 4.26 [95% CI, 1.28-14.23; P = .02]; very high-risk SHR, 62.98 [95% CI, 19.24-206.17; P < .001]), DM (high-risk SHR, 2.2 × 107 [95% CI, 4.7 × 103-1.1 × 1011; P < .001]; very high-risk SHR, 6.3 × 108 [95% CI, 1.4 × 105-2.9 × 1012; P < .001]), and DSD (high-risk SHR, 4.02 [95% CI, 1.18-13.71; P = .03]; very high-risk SHR, 93.87 [95% CI, 29.19-301.85; P < .001]). Adjusted 5-year cumulative incidence was significantly higher in very high- vs high- and low-risk groups for LR (9.4% [95% CI, 9.2%-14.0%] vs 1.5% [95% CI, 1.4%-2.1%] and 0.8% [95% CI, 0.5%-1.2%], respectively), NM (7.3% [95% CI, 6.8%-10.9%] vs 0.5% [95% CI, 0.4%-0.8%] and 0.1% [95% CI, 0.03%-0.3%], respectively), DM (3.9% [95% CI, 2.6%-5.6%] vs 0.1% [95% CI, 0.04%-0.2%] and 0.01% [95% CI, not applicable], respectively), and DSD (10.5% [95% CI, 10.3%-15.4%] vs 0.5% [95% CI, 0.4%-0.8%] and 0.1% [95% CI, 0.04%-0.3%], respectively). Compared with CSCCs treated with WLE, those treated with Mohs or PDEMA had lower risk of LR (SHR, 0.65 [95% CI, 0.46-0.90]; P = .009), DM (SHR, 0.38 [95% CI, 0.18-0.83]; P = .02), and DSD (SHR, 0.55 [95% CI, 0.36-0.84]; P = .006). Conclusions and Relevance: The findings of this cohort study suggest that the NCCN high- and very high-risk groups identify CSCCs at greatest risk for developing poor outcomes. Further, Mohs or PDEMA resulted in lower LR, DM, and DSD compared with WLE.

Immune status does not independently influence cutaneous squamous cell carcinoma metastasis and death when stratified by tumor stage: A dual-center retrospective cohort analysis of primary N0 disease.

BACKGROUND: Although immunocompromised patients have a higher risk of developing cutaneous squamous cell carcinomas, it is unknown whether immune status is an independent risk factor for poor outcomes. OBJECTIVE: To compare cutaneous squamous cell carcinoma outcomes in immunocompromised and immunocompetent patients when controlling for T-stage. METHODS: We performed a retrospective cohort study at 2 tertiary care centers, examining 989 primary tumors from 814 immunocompromised patients (solid organ transplant: 259 [31.7%], chronic lymphocytic leukemia: 113 [13.9%]) and 6608 tumors from 4198 immunocompetent patients. Our primary outcome was the composite of disease-specific death or tumor metastasis ("poor outcomes"). RESULTS: Immunocompromised patients had 50% more high T-stage tumors (ie, Brigham and Women's Hospital stage T2b and T3), than immunocompetent patients (3.3% vs 4.9%, respectively; P < .001). Significant predictors of poor outcomes included tumor stage (sub hazards ratio [SHR], 14.8 for high T-stage tumors; 95% confidence interval [CI], 8.0-27.6; P < .001) and male sex (SHR, 2.3; 95% CI, 1.4-3.8; P = .002). Immune status was not a significant predictor (SHR, 1.04; 95% CI, 0.69-1.6; P = .85). LIMITATIONS: This study is retrospective. CONCLUSION: Although immunocompromised patients had 50% more high T-stage tumors than immunocompetent patients, immunocompromised patients had a similar chance of metastasis and disease-specific death when adjusting for T-stage in our cohort of primary tumors.

Adjuvant radiation following clear margin resection of high T-stage cutaneous squamous cell carcinoma halves the risk of local and locoregional recurrence: A dual-center retrospective study.

BACKGROUND: Although adjuvant radiation (ART) following clear margin surgery is recommended for select high-risk cutaneous squamous cell carcinomas, efficacy data are limited. OBJECTIVE: To evaluate the impact of ART on outcomes following clear margin surgery for high T-stage cutaneous squamous cell carcinomas. METHODS: A 20-year retrospective cohort study at 2 academic centers of high T-stage cutaneous squamous cell carcinomas (Brigham and Women's Hospital T2b or T3) with negative histologic margins post resection. Local recurrence (LR) and locoregional recurrence (LRR) were compared by whether tumors received ART or observation. RESULTS: A total of 508 tumors were included, of which 96 underwent ART (ART+). ART+ had a lower 5-year cumulative incidence of LR (ART+, 3.6% [95% CI, 1.6%-7.7%] vs ART-, 8.7% [95% CI, 6.3%-12.0%]) and LRR (ART+, 7.5% [95% CI, 4.4%-11.9%] vs ART-, 15.3% [95% CI, 11.9%-22.1%]). Recurrent tumors ≥6 cm or Brigham and Women's Hospital T3 tumors were classified as high-risk due to a higher 5-year cumulative incidence of LRR (High-risk, 26.3% [95% CI, 19.0%-35.7%]). High-risk tumors treated with ART had a lower 5-year cumulative incidence of LRR (ART+, 17.2% [95% CI, 11.9%-26.4%] vs ART-, 31.0% [95% CI, 26.1%-40.8%]). LIMITATIONS: Retrospective design, heterogeneous population, variations in radiation protocols. CONCLUSION: ART following clear margin surgery for high T-stage cutaneous squamous cell carcinomas resulted in half the risk of LR and LRR.

Limited Toxicity of Hypofractionated Intensity Modulated Radiation Therapy for Head and Neck Cancer.

BACKGROUND/AIM: Hypofractionated radiation therapy is not commonly used in head and neck cancers (HNC) due to increased toxicity observed in historical cohorts. This study reviews our institutional experience using hypofractionated intensity modulated radiation therapy (H-IMRT) for HNC. PATIENTS AND METHODS: A retrospective cohort study of 56 patients with HNC treated with H-IMRT with ≥50 Gy in 20 fractions was conducted. The primary outcomes were acute and late toxicity. RESULTS: Two-year locoregional control was 87% and median overall survival was 46 months. There were no acute or late grade 4 or 5 toxicities. Acute grade 2 and 3 toxicity was seen in 79% (N=44) and 25% (N=14), respectively. Late grade 2 toxicity was seen in 9% (N=5). No patients required the placement of a feeding tube or tracheostomy. CONCLUSION: H-IMRT for the definitive or post-operative treatment of HNC using ≥50 Gy in 20 fractions appears safe and well tolerated with modest toxicity.

Higher metastasis and death rates in cutaneous squamous cell carcinomas with lymphovascular invasion.

BACKGROUND: Lymphovascular invasion (LVI) is an aggressive histologic finding but is excluded from current staging systems due to its lack of demonstrated independent prognostic significance. OBJECTIVE: To evaluate the impact of LVI on cutaneous squamous cell carcinoma tumor outcomes. METHODS: In total, 10,707 cutaneous squamous cell carcinoma tumors from a 20-year, retrospective, multicenter cohort were stratified by the presence (LVI+) or absence (LVI-) of LVI. Outcomes (local recurrence, in-transit metastasis, nodal metastasis, disease-specific death) were compared based on low (Brigham and Women's Hospital [BWH] stage T1/T2a) and high (BWH T2b/T3) tumor stages. RESULTS: Of the 10,707 tumors, 78 had LVI. The analysis of low-stage BWH tumors showed the LVI+ group had a significantly higher 5-year cumulative incidence of local recurrence (LVI+: 12.3%; LVI-: 1.1%; P < .01), metastasis (LVI+: 4.2%; LVI-: 0.4%; P < .01), and disease-specific death (LVI+: 16.2%; LVI-: 0.4%; P < .01). The analysis of BWH high-stage tumors showed the LVI+ group maintained a higher 5-year cumulative incidence of metastasis (LVI+: 28.5%; LVI-: 16.8%; P = .06) and disease-specific death (LVI+: 25.3%; LVI-: 13.9%; P = .03), however, there was no difference in local recurrence (LVI+: 16.3%; LVI-: 15.8%; P = .11). LIMITATIONS: Retrospective study design. CONCLUSION: LVI+ cutaneous squamous cell carcinomas have higher rates of metastasis and death at 5 years. Future staging systems should consider incorporating LVI.