Differences in patterns of survival in metastatic adenoid cystic carcinoma of the head and neck.

BACKGROUND We examined the assumption in conventional teaching about metastatic adenoid cystic carcinoma (ACC) being an indolent type of disease. METHODS A single center analysis of 105 cases of ACC was performed. Radiographs were reviewed and tumor response to chemotherapy was measured. Distant disease-free survival (DDFS) and time to death since distant metastases diagnosis were analyzed. RESULTS Forty-two percent of the patients were diagnosed with distant metastases. DDFS showed significant negative associations with advanced T classification, N+ classification, solid type tumor, and positive surgical margins. Distant metastases (91%) developed in the first 5 years after presentation. Median distant metastatic survival was 13.8 months. The most frequent organ sited was the lung. Solid type ACC showed a preponderance for multiorgan metastases (17/28; 61%). Distant metastases seemed not to occur in case of clear surgical margins. Solid type ACC had a significant poorer survival after development of distant metastases. CONCLUSION Metastatic ACC is not always an indolent disease. © 2016 Wiley Periodicals, Inc. Head Neck 39: 456-463, 2017.