Survival outcomes of perineural spread in head and neck cutaneous squamous cell carcinoma.

AIM: To present an institution's experience and survival outcomes for patients with head and neck cutaneous squamous cell carcinoma (HNcSCC) and perineural spread (PNS). METHOD: Retrospective study of patients with HNcSCC and PNS treated between January 2010 and August 2020 from the Sydney Head and Neck Cancer Institute database, Sydney, Australia; a high-volume, tertiary, academic head and neck centre. Patient demographics, primary site, involved cranial nerves, treatment modality, loco-regional failure and survival data were obtained. RESULTS: Forty-five patients were identified, of which 32 patients were male (71%). Mean age at diagnosis was 68.7 years (range 43-90). Median follow-up was 16.1 months (range 1-107). The trigeminal nerve was most frequently involved (n = 30, 66.6%) followed by facial nerve (n = 13, 28.9%). Most patients underwent surgery followed by radiotherapy (n = 33, 73%) and eight received definitive radiotherapy. The median overall survival (OS) was 4.5 years (95% CI 3.71-5.38), median disease-specific survival 5.1 years (95% CI 4.21-5.97) and median disease-free survival (DFS) was 1.7 years (95% CI 1.11-2.22). The estimated 5-year OS and DFS were 45% and 25%, respectively. Patients treated with surgery and adjuvant radiotherapy with a clear proximal nerve margin had favourable DFS (P = 0.035) and trended towards better OS (P = 0.134) compared with patients with an involved nerve margin. Patients treated surgically with involved proximal nerve margins had similar outcomes compared with patients with treated definitive radiotherapy (HR 0.80, 95% CI 0.29-2.22, P = 0.664). CONCLUSION: The likelihood of achieving a clear proximal nerve margin should be a strong consideration in the selection of appropriate patients for primary surgery.