Long-term analysis of prognostic risk factors impacting surgical outcomes in patients with external auditory canal carcinoma.

Background: Malignant neoplasms of the external auditory canal (EAC) are rare. No consensus on management has emerged.

Objective: To determine possible risk factors influencing tumorgenesis and prognosis of EAC carcinoma.

Materials And Methods: 108 patients (87 men/21 women) with an average age of 74 ± 13.8 years were recruited from 2005 to 2019 at Department of Otorhinolaryngology, Head and Neck Surgery Heidelberg. The follow-up interval was 43.62 ± 55.39 months. Partial and (sub)total ablative otis, supplementary surgery (petrosectomy, parotidectomy, neck dissection, mastoidectomy) and adjuvant radio(chemo)therapy belonged to treatment options. TNM status was determined at time of diagnosis using the AJCC staging system.

Results: 63.9% of patients underwent a total ablative otis. Tumor recurrence was seen in 24.1%. The 1-year survival rate was 87%, the 5-year survival rate was 52%, the mean overall survival (OS) was 3.82 ± 4.6 years. Male EAC carcinoma patients had a better OS (p < 0.001), PFS (p < 0.001) and DSS (p = 0.02) than females. T1 patients had a better OS (p = 0.01), PFS (p = 0.01) and DSS (p < 0.001) than T4 patients. Lymph node but not distant metastasis, tumor grading, perineural, venous and lymphatic invasion, histology, age and tumor localization influenced the OS in EAC carcinoma patients (p = 0.04). The more radical the ablative otis, the worse the OS (p = 0.002), PFS (p = 0.02) and DSS (p < 0.001). Radio(chemo)therapy did not improve the OS.

Conclusions: EAC carcinoma are difficult to treat and benefit from early diagnosis so that a radical combined treatment approach does not need to be used.