PURPOSE/OBJECTIVE(S): Unresectable locally advanced cutaneous squamous cell carcinoma (ULACSCC) of the head and neck (H&N) has historically been treated with radiation therapy (RT), particularly for clinical perineural spread (PNS). Cemiplimab monotherapy has emerged as an alternative treatment for these patients. We sought to evaluate local control with cemiplimab monotherapy in this population. MATERIALS/METHODS: This single-institution retrospective study was IRB approved (HUM00186167). We reviewed all 45 patients treated with cemiplimab between 2018 - 2020. To limit the analysis to intact H&N ULACSCC receiving cemimplimab monotherapy (n = 31), we excluded 14 patients for adjuvant cemiplimab after RT (n = 3) or surgery (n = 2), concurrent cemiplimab with RT (n = 3), distant disease only (n = 2), or non-H&N primary (n = 4). ULACSCC was categorized as unresectable clinical and/or radiographic PNS, orbital disease (OD), or unresectable disease involving lymph nodes, skin, or calvarium of the H&N (non-PNS). Clinical variables including disease categorization, immunocompetence defined as no autoimmune disease or prior immune modulation within 4 weeks of cemiplimab initiation (immunosuppression, steroids, or immunotherapy targeting PD-1 or CTLA-4), duration of cemiplimab, reasons for stopping cemiplimab, and patterns of recurrence were assessed. Descriptive statistics were used to summarize patient-, treatment-, and disease-related characteristics, and chi-square test was used to compare immunocompetency. With death as a competing risk, locoregional control (LRC) was defined clinically or radiographically. RESULTS: Of the 31 patients, 11 had PNS, 4 had OD, and 16 had only non-PNS disease, with synchronous metastases present in 26% overall. Median age was 72.5 (IQR: 65.7 - 84.6) years. Median follow-up was 18.6 (IQR: 10.3 - 20.9) months. 45% had H&N RT followed by disease progression prior to cemiplimab. 55% were immunocompetent, with similar immunocompetency among PNS, OD, non-PNS patients (P = 0.6). The 1 year LRC approached 70% or more for all groups (Table 1). 1 year OS was 70% (PNS), no events (OD), and 60.8% (non-PNS). PNS patients completed more cycles over a longer duration than OD or non-PNS patients (Table 1). Reasons for stopping cemiplimab were completion of treatment with complete response (38%), disease progression (23%), treatment-related toxicity (3%), declining KPS (16%), and co-morbidity-related death (6%). 3 patients continue on therapy. CONCLUSION: Cemiplimab monotherapy is efficacious in H&N ULACSCC, with comparable LRC among PNS, orbital, and non-PNS disease in our study. Anti-PD1 monotherapy may represent a reasonable alternative to RT in this population. Prospective comparison may be warranted.
|Original language||English (US)|
|Journal||International journal of radiation oncology, biology, physics|
|State||Published - Nov 1 2021|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cancer Research