Treatment outcomes and prognostic features in adenoid cystic carcinoma originated from the head and neck.

Surgery is the main treatment modality for adenoid cystic carcinoma (ACC) originated from the head and neck. However, the extensive local infiltrative and perineural spread related to this malignancy often cause difficulty to achieve high tumor control. The aim of this study is to evaluate the efficacy of postoperative radiotherapy (RT) in ACC, and to identify prognostic variables associated with treatment outcomes. A retrospective review of 101 patients diagnosed with ACC in the head and neck region was performed. T stage distribution was T1, 25; T2, 35; T3, 18; and T4, 23 patients. All patients were grouped into two arms: surgery alone or combined with postoperative radiotherapy. The 5-year local-regional control (LRC), overall survival (OS) and disease-free survival (DFS) rates for all the patients were 70.5%, 91.7% and 63.2%, respectively. On univariant analysis, postoperative radiotherapy did improve the 5-year LRC and DFS compared to surgery alone (81.0% vs. 53.4%, p=0.0003 and 71.3% vs. 50.0%, p=0.0052, respectively). And patients with T1-T2 lesions achieved better treatment outcomes, whereas stage T3-T4 was associated with high local failure and poor disease-free survival. Furthermore, multivariate analysis revealed that the addition of radiotherapy and early lesions were both favorite predictors for local control and survival rates. The prognosis for ACC of the head and neck was excellent. Surgery combined with postoperative radiotherapy significantly reduced the local failure, and further improved disease-free survival. Nevertheless, the relatively high distant metastasis was an obstacle of curing the ACC patients.