Oncologic Outcome and Distant Metastasis of Head and Neck Adenoid Cystic Carcinoma

Abstract

Background/Objectives Adenoid cystic carcinoma is the second most common salivary carcinoma. It occurs commonly in the submandibular gland, sublingual gland and minor salivary gland. Local recurrence and distant metastasis are the leading cause of death. The aim of this study was to evaluate long-term oncologic outcomes of patients with head and neck adenoid cystic carcinoma focusing on distant metastasis.

Materials & Methods We retrospectively studied 39 patients who were diagnosed with and treated for adenoid cystic carcinoma of the head and neck from December 1996 to May 2018. The clinicopathologic characteristics of patients such as age, sex, primary site and TNM stage, and treatment methods, recurrence and distant metastasis after treatment, survival rate, and treatment method for recurrence were analyzed.

Results Of 39 patients, 18 were males and 21 were females, and the mean age was 5.9±14.4 (28-89) years. The most common primary site was oral cavity (12 cases), and followed by sino-nasal cavity (11 cases), parotid gland (5 cases), and etc. For treatment, 17 patients underwent surgery alone, 16 received surgery with postoperative radiation therapy, and 3 patients received radiation therapy only. Three patients refused any further treatments. Recurrence occurred in 15 patients. The most common site of recurrence was the lung. The mean time to recurrence was 31.7 months. The 5 and 10 years’ overall survival rate was 79.3% and 74%, respectively. The 2 and 5 years’ overall survival rate was 69.6% and 62.6% in patients with distant metastasis.

Conclusion Distant metastasis is an important prognostic factor in adenoid cystic carcinoma, and eventually one third of patients have distant metastasis, especially in the lung. An appropriate treatment for lung metastasis is necessary because some patients with pulmonary metastasis survive for a quite long time.