Clinical Outcomes and Prognostic Factors of Adenoid Cystic Carcinoma of the Head and Neck

Background: Adenoid cystic carcinoma (ACC) is a salivary gland malignancy with unpredictable growth and poorly understood prognostic factors. Patients and Methods: A database search of patients treated at a single Institution was used to identify patients with histologically-confirmed ACC. Patient, tumor, and treatment characteristics were examined via review of medical records. Results: Overall survival of 70 patients identified at 5, 10, and 15 years was 80.4%, 61.3%, and 29.4%, respectively. Disease recurrence was seen in 31.9%; of these, 72.7% developed distant metastasis. Older age, higher stage, skull base involvement, positive margins, and metastatic disease, but not local recurrence, predicted a worse overall survival. Higher stage and skull base disease were also associated with shorter disease-free survival. While lung metastasis was the most common, vertebral metastasis was associated with poorer survival. Conclusion: Disease stage, positive margins, skull base involvement, perineural invasion, time to recurrence, and location of metastasis, but not nodal involvement, could serve as poor prognostic factors in ACC.