ABSTRACT
Background and purpose:Adenoid cystic carcinoma is a rare tumor from salivary gland tissues; the incidence is about 1% to 2% of all head and neck malignant tumors. The incidence of adenoid cystic carcinoma of nasal sinuses is lower. Its characteristics include slow growth, less lymph node metastasis, easy to tissue invasion and growing along the nerves. It has high rate of recurrence and distant metastasis. Patients with the disease always have poor prognosis. This study aimed to investigate the prognosis and its impacting factors in Chinese patients with adenoid cystic carcinoma of nasal cavity and paranasal sinuses.Methods:This was a single center, prospective, observational study in Chinese patients with adenoid cystic carcinoma of nasal cavity and paranasal sinuses. Total 104 patients who received radiotherapy during the period between Sep. 2000 and Nov. 2012 were included and followed up for median 5.1 years. Kaplan-Meier, log-rank test, and COX proportional hazards model were used for survival-related analysis. Results:Mean age of patients was (54.5±11.5) years with equal numbers of males and females. The most common primary site was nasal cavity (63.5%) followed by maxillary sinus (29.8%). 76.0% of patients were at clinical stagesⅢ-Ⅳ, 56.7% of patients with positive surgical margin and 34.6% of patients with positive nerve invasion. In terms of treatment regimens, 67.3% of patients received postoperative radiotherapy, 27.9% received preoperative radiotherapy, only 4.8% received pure radiotherapy, and 29.8% received chemotherapy combined with surgery and radiotherapy.Conformal radiation therapy (CRT) was the most common radiotherapy which was used in 81.7% of patients, followed by intensity-modulated radiation therapy (IMRT) which was used in 18.3% of patients. Finally, 18 patients had recur-rence and 28 patients had distant metastasis. The most common metastatic site was lung, and nerve invasion was the independent risk factor for recurrence or metastasis (P=0.000 2). The overall survival rates of 5 and 10 years were 77% (95%CI: 68.7%-85.3%) and 67.8% (95%CI: 57.8%-77.9%), respectively. The disease-free survival rates of 5 years and 10 years were 57.8% (95%CI: 48.0%-67.7%) and 56.4% (95%CI: 46.3%-66.4%), respectively. Recurrence or distant metastasis was critical risk factor for overall survival (HR=60.1, 95%CI: 8.15-443.1,P<0.0001). Positive nerve invasion was a signiifcant factor for disease-free survival (HR=2.99, 95%CI: 1.642-5.445,P=0.0002). The primary sites, clinical stage, status of surgical margin, or radiotherapy methods had no impact on the prognosis of patients with adenoid cystic carcinoma of nasal cavity and paranasal sinuses.Conclusion:Positive nerve invasion, recurrence or distant metastasis may be important factors affecting the prognosis of Chinese patients with adenoid cystic carcinoma of nasal cavity and nasal sinuses.