Clinicopathologic and prognostic factors in adenoid cystic carcinoma of head and neck minor salivar

Abstract:

Purpose：This study was to investigate clinicopathologic characteristics and prognostic factors in adenoid cystic carcinoma of head and neck minor salivary glands. Materials and Methods： We conducted a retrospective review of 130 patients with adenoid cystic carcinoma of head and neck minor salivary glands that were evaluated between 2000 and 2013 in Beijng Tongren Hospital.

Results： Five-year overall survival and disease-free survival rates were 80.8% and 55.6%. Local recurrence rate was 40%, regional recurrence 3.8%, and distant metastasis was 28.5%. On univariate analysis, solid histological subtype, perineural invasion, positive surgical margins and advanced stages were found to be poor prognostic indicators. On multivariate analysis, solid histological subtype and positive surgical margins were significant prognostic factors of worse overall survival. Conclusions： Solid histological subtype and positive surgical margins were the most important predictors of poor outcome in adenoid cystic carcinoma of minor salivary glands. Surgery with postoperative radiation were recommended treatment and offered durable local control.

Introduction

Adenoid cystic carcinoma (ACC) is a rare tumor that originates within salivary glands. ACC comprises approximately one-quarter of all salivary gland tumor, which accounts for 3 to 5% of all head and neck malignancies1, 2 . Approximately 42-61% of ACC arises within the minor salivary glands, of which the palate is the most common site of origin3, 4 . The clinical behavior of ACC is unique among salivary gland tumors. It has a distinct natural history characterized by slow-growing but extensive local invasion and perineural spread, with late development of distant metastasis. Due to its rarity, there is some controversy over the clinical and histological factors that affect the survival of patients with ACC. Gender, perineural invasion (PNI), efficacy of adjuvant treatment, and the site of origin were found to be significant prognostic factors by some authors, whereas others found that they had no impact on survival5-9 . Since that prognostic factors are important in guiding treatment as well as counseling patients, and there are few large case series that specifically address the prognostic factors of ACC of minor salivary gland10, 11 . We conducted this retrospective study to report our experience to determine the clinicopathologic characteristics and prognostic factors in patients with ACC of the head and neck minor salivary gland.