The Efficacy of Radiotherapy without Surgery for External Auditory Canal Squamous Cell Carcinoma

Abstract

External auditory canal (EAC) cancer is a rare disease for which there are no adequate evidence-based treatment strategies. Radiotherapy is often used as the initial treatment to preserve the organ. This study aimed to elucidate the efficacy of radiotherapy for EAC squamous cell carcinoma (SCC). Patients with T1 disease were treated with radiotherapy alone. Patients with T2-4 disease were treated with chemoradiotherapy. The median follow-up period was 30.4 months. The 3-year local control (LC) rate for all patients was 51%, the disease-free survival (DFS) rate was 44%, and the overall survival (OS) rate was 73%. For T1-3 disease, the 3-year LC rate was 74%, DFS was 62%, and OS was 89%. However, for T4 disease, the 3-year LC rate was 17%, DFS was 17%, and OS was 50%. In a univariate analysis, only the T-category was a significant factor for LC and DFS (p = 0.006 and 0.02, respectively). All local recurrences were within the high-dose irradiated area. The results of this study suggest chemoradiotherapy can be an alternative to a combination of surgery and postoperative radiation for T1-3 SCC of the EAC. However, the efficacy of chemoradiotherapy in T4 cases was inadequate.

Malignant tumors of the external auditory canal: diagnosis, treatment, genetic landscape, biomarkers, and clinical outcome

“…T3 patients who could not undergo the surgery had a poor prognosis, similar to that of T4 patients. So, besides subtotal temporal bone resection, lateral temporal bone resection could be a treatment option for some T3 patients [13].…”

“…For patients bearing inoperable tumors, 65–75 Gy is recommended as palliative therapy. In fact, the efficacy of CT-based three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) without surgery has been evaluated in 15 patients with SCC of the EAC, showing that chemoradiotherapy is inferior compared to surgery and post-operative radiation [ 14 ].…”