External auditory canal carcinoma: clinical characteristics and long-term treatment outcomes

Purpose Evidence-based treatment recommendations for external auditory canal (EAC) carcinoma are lacking in available literature. This study aims to evaluate the clinical characteristics and long-term outcomes of EAC carcinoma in a tertiary referral centre in a period of 15 years and identify independent prognostic factors. Methods Retrospective observational study enrolling all patients with primary EAC carcinoma who underwent primary surgical treatment at the Portuguese Institute of Oncology (Lisbon) between 2004 and 2018. Epidemiological, clinical, histopathological and surgical data were retrieved from clinical records and analysed. Results Twenty-seven patients were identified, with a median age of 77 years (range 29-92 years) and a slight female predominance (59.3%). Squamous cell carcinoma (55.6%) was the most common histological type, followed by basal cell carcinoma (40.7%) and ceruminous adenocarcinoma (3.7%). Pittsburgh tumour staging was distributed as early stage in 51.9% (I: 40.7%; II: 11.1%) and advanced stage in 48.1% (III: 29.6%; IV: 18.5%). Median follow-up period was 21 months (interquartile-range: 47). Four patients (14.8%) showed recurrence; recurrence rate was significantly higher in individuals aged < 60 years (p = 0.025) and with lymphovascular invasion (p = 0.049). Median overall survival was 88 months and estimated 2-year and 5-year overall survival rates were both 66%. Survival rates were higher in early stage patients (p = 0.021) and in those without facial palsy (p = 0.032). Conclusion Based on the available evidence in this review, individuals aged < 60, facial nerve impairment, advanced stage lesions, presence of lymphovascular invasion and squamous cell carcinoma histology are all associated with poor outcome and may be considered when discussing optimal treatment strategies in patients with EAC carcinoma.