Surgical outcomes of 43 cases with adenoid cystic carcinoma of the external auditory canal

PurposeTo evaluate surgical outcomes for adenoid cystic carcinoma (ACC) of the external auditory canal (EAC).MethodsForty-three patients with ACC of the EAC in Eye and ENT Hospital of Fudan University were analyzed retrospectively for survival. The patients were staged according to the modified Pittsburgh staging system. Thirteen patients with T1 stage underwent local resection (LR), 6 patients with T1 stage underwent lateral temporal bone resection (LTBR), and 8 patients with T1 stage underwent LTBR including superficial parotidectomy (SP). Two patients with T2 stage underwent LTBR, and 1 patient with T2 stage underwent LTBR + SP. Three patients with T3 stage underwent LTBR. One patient with T4 stage underwent LTBR, two patients with T4 stage underwent subtotal temporal bone resection (STBR), and 7 patients with T4 stage underwent LTBR + SP.ResultsOf all patients that underwent surgery, 13 died of their primary cancers during the follow-up time. The 5-year survival rates of patients with T stages 1 through 4 were 85%, 67%, 67%, and 30%, respectively. There was statistically significant difference in 5-year survival rate between T1 and other stages (T2, T3, T4) using the log-rank test (p < 0.05). There was significant difference in 5-year survival rate between T4 and other stages using the log-rank test (p < 0.05). The 5-year survival rates after LR, LTBR or LTBR plus SP for T1 were 77%, 87% and 100%, respectively. The 5-year survival rates after LTBR, STBR or LTBR plus SP for T4 were 0%, 50% and 29%, respectively. The 5-year survival rates for 19 patients with clear surgical margins and 24 patients with positive margins were 89% and 54%, respectively. The 5-year survival rates of patients with radiotherapy and without radiotherapy were 62% and 86%, respectively.ConclusionAn en bloc resection including superficial parotidectomy is favored in an effort to produce negative surgical margins for ACC of the EAC. Adjunctive radiotherapy is used for patients with positive margins and in advanced lesions.