Outcomes of radiotherapy in advanced external auditory canal cancer.

Takuya Nagano,Mio Kojima,Keiko Nakagawa,Kazuma Toda,Ryo-Ichi Yoshimura

doi:10.1093/jrr/rrz010

Takuya Nagano, Mio Kojima + Show 3 more

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https://doi.org/10.1093/jrr/rrz010

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Abstract

External auditory canal cancer (EACC) is a rare malignant tumor. In the present study, we retrospectively evaluated the treatment results in patients with advanced EACC who were treated using external-beam radiotherapy (EBRT) combined with chemotherapy or radical surgery. Overall, 21 patients with Stage III (n = 8) or Stage IV (n = 13) EACC who underwent initial treatment at our hospital between 2003 and 2016 were enrolled in this study. The 2-year overall survival (OS) and locoregional control (LRC) rates of all patients were 62% and 71%, respectively. The 2-year OS and LRC rates in patients who had received EBRT and concurrent chemotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF, n = 6) were 100%. These results were higher than the 2-year OS and LRC rates of 62% and 69%, respectively, in patients who had received radical surgery and EBRT (n = 13). The rates were 0% in those who had neither received TPF nor undergone surgery in addition to EBRT (n = 2). Grade 3 bone or soft tissue necrosis was observed in 2 patients who had undergone surgery and postoperative EBRT. Our data suggest that the combination therapy of EBRT and surgery and/or chemotherapy may be the most effective treatment options for advanced EACC, and EBRT with concurrent chemotherapy with TPF is potentially the most acceptable.

Highlights

External auditory canal cancer (EACC) is a rare malignant tumor that affects 1–6 per 1 million population-years [1, 2]
23 patients with EACC received external-beam radiotherapy (EBRT) during the specific period; 2 patients were excluded because they had been treated with Cyberknife to prevent the recurrence of EACC; the remaining 21 patients were enrolled in the present study
The 2-year overall survival (OS) rate of all EACC patients who received EBRT was 62% and that of Stage III and IV patients was 71% and 56%, respectively; these rates were similar to those reported in prior studies or a little better than them

Summary

Introduction

External auditory canal cancer (EACC) is a rare malignant tumor that affects 1–6 per 1 million population-years [1, 2]. The low numbers of patients in studies to date have led to an appropriate treatment strategy for EACC remaining controversial. Several clinical reviews and meta-analyses have concluded that radical primary surgical treatment combined with postoperative radiotherapy should be recommended as the standard of care for advanced EACC [3,4,5]. Certain study groups have reported the results of chemoradiotherapy as a non-surgical treatment, and Shinoyama et al [7] have reported a better prognosis with chemoradiotherapy than with other modalities, such as surgery with/without external-beam radiotherapy (EBRT), EBRT alone, or proton therapy, the number of studies are still limited. At our institute we have treated patients with EACC with EBRT and radical surgery and/or concurrent chemotherapy. We aimed to retrospectively evaluate the treatments and compare their outcomes

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