Outcomes of radiotherapy in advanced external auditory canal cancer

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.

Sites of invasion of cancer of the external auditory canal predicting oncologic outcomes

“…They concluded that definitive CRT, surgery, and adjuvant chemotherapy resulted in equivalent OS of the patients. In recent studies, they found that definitive CRT showed equivalent survival rates of patients with advanced EAC cancer compared to surgical treatment 6,7,9,13 . In fact, approximately two‐thirds of the patients with EAC cancer in our series underwent CRT, and their treatment outcomes were almost equal to those of the patients who underwent surgical treatment (Figure 2).…”

“…In recent studies, they found that definitive CRT showed equivalent survival rates of patients with advanced EAC cancer compared to surgical treatment. 6,7,9,13 In fact, approximately two-thirds of the patients with EAC cancer in our series underwent CRT, and their treatment outcomes were almost equal to those of the patients who underwent surgical treatment (Figure 2). The 3-year overall survival rate of 55.0% of the patients with T4 EAC cancer was at least as much as that of the previous reports (Table 5).…”

Evaluation of subclasses for T4‐classified squamous cell carcinoma of the external auditory canal

“…Shiga et al showed that T4‐classified tumors were treated primary with chemoradiotherapy when the tumor involves the cochlear, jugular foramen, dura mater invasion, or brain invasion 30 . Results of other studies also presented beneficial effects of chemoradiotherapy on survival outcomes of EAC SCC, but all studies used different chemoradiation protocols and the sample sizes were too small for meaningful evaluation 31–38 …”

The efficacy of computed tomography imaging-based radiotherapy for external auditory canal squamous cell carcinoma

“…Several studies on treatment strategies for EAC cancer concluded that a combination treatment of surgery and postoperative radiation was the most curative for T2−3 disease [3,5,6,16,17]. However, adverse events from surgery are not uncommon [3,18].…”