Non-melanoma skin cancer of the external auditory canal: long-term outcomes of a tertiary head and neck unit.

Purpose: External auditory canal (EAC) skin cancer is often diagnosed at advanced stages, leading to poor survival outcomes. Our study aims to describe disease characteristics, treatments and outcomes of patients with EAC cancer, increasing understanding of the management of this rare disease.

Methods: Retrospective, observational study including patients with non-melanoma EAC skin cancer treated at Guy's and St Thomas' Head and Neck Unit from 2012 to 2021, with follow-up until October 2023. Patient with EAC or auricular primaries extending into the EAC were included. Demographic, histopathological, and surgical data were obtained from electronic records.

Results: Thirty-eight patients were included, 86.8% treated with curative intent. The median follow-up was 49.9 months. One, three, and five-year overall survival for patients treated curatively were 100%, 96.9% and 75.3%, respectively, versus 40.0%, 0.0% and 0.0% for palliative. 68.4% had advanced disease (Pittsburgh staging, III: 18.4%, IV: 50.0%). 39.5% were treated after recurrent or persistent disease. Histological subtypes included squamous cell carcinoma (60.5%), basal cell carcinoma (26.3%) and others (13.2%). Among those treated surgically (n = 31), 74.2% underwent lateral temporal bone resection and 29.0% wide local excision. 83.9% had parotidectomy, neck dissection or both. 51.6% received post-operative radiotherapy/chemoradiotherapy. Advanced stage was significantly associated with reduced overall survival (p = 0.05) but not disease-free survival (p = 0.25). No primary site features, regional metastasis (p = 0.63), direct parotid invasion (p = 0.71) or age (p = 0.15) significantly impacted survival.

Conclusion: According to the good outcomes reported, this study suggests lowering the threshold for radical treatment may improve outcomes for patients with potentially poor prognostic features.