Analysis of Failure in Patients with Adenoid Cystic Carcinoma of the Head and Neck

Background: Adenoid cystic carcinoma (ACC) accounts for less than 1% of all head and neck malignancies. It is a locally aggressive tumor with a high prevalence of distant metastases. The current study aimed to identify independent predictors of outcome and to characterize the patterns of failure.

Methods: This is an international retrospective clinicopathologic review of 495 ACC patients treated between 1985 and 2011 in 9 cancer centers worldwide.

Results: Five-year overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were 76%, 80% and 68%, respectively. Independent predictors of OS and DSS were: age, site, N classification and presence of distant metastases. Adjuvant treatment had no significant influence on outcome (p = 0.6). Advanced N stage (p = 0.004) age ≥70 years (p = 0.01) and bone invasion (p = 0.001) were associated with shorter DFS on multivariate analysis. Metastasis sites were: lung (20%), bone (4%), liver (3%) and brain (1%). Median time to diagnosis of distant metastasis was 30 months (range 2–192). Age ≥70 years, tumor site, orbital invasion and N stage were independent significant predictors of distant metastasis. Metastasis site had a significant impact on OS (p = 0.04) and DSS (p = 0.03).

Conclusion: The clinical course of ACC was slow but persistent. Paranasal sinus origin was associated with the lowest distant metastasis rate but with the poorest outcome. We found no impact of adjuvant radiation or chemoradiation on outcome. These prognostic estimates should be taken into consideration when tailoring treatment for patients with ACC.