Objective: To investigate the prognosis of adenoid cystic carcinoma (ACC) in minor salivary glands and its influencing factors.
Methods: Clinical data of 52 patients with ACC in minor salivary glands were reviewed. The distribution of stage was as follows: stage I (6%), stage II (21%), stage III (27%) and stage IV (46%). Counting data was analyzed by χ(2) test or Fisher's exact. Survival rates were calculated by Kaplan-Merier method. Statistical significance of differences in the cumulative survival curves was evaluated using the Log-rank test. Multivariate analysis was performed by Cox proportional hazard model.
Results: All patients underwent primary tumor radical resection, 39 patients (75%) received postoperative radiation. The regional recurrence rate was 37% and distant metastasis rate was 21%. The 5-, 10-year cumulative local control rate were 68% and 63% respectively. The 5-, 10-year cumulative distant control rate were 86%, 68% respectively. The 5-, 10-year tumor specific survival rates were 70% and 54% respectively. Multivariate analysis showed that T stage, lymph node metastasis and perineural invasion were relevant to the tumor specific survival of ACC in minor salivary glands.
Conclusions: Recurrence and metastasis were the main cause of treatment failure of ACC in minor salivary glands. T stage, lymph node metastasis and perineural invasion were the independent prognostic factors of ACC in minor salivary glands. Radical surgery and reasonably postoperative radiotherapy were the main treatment strategy.