Cavernous sinus involvement is not a risk factor for the primary tumor site treatment outcome of Sinonasal adenoid cystic carcinoma

BACKGROUND Sinonasal adenoid cystic carcinoma is a rare malignancy of the head and neck. Cavernous sinus invasion from sinonasal adenoid cystic carcinoma and its related management have rarely been investigated. This study evaluated the relationship between treatment outcome and cavernous sinus involvement in addition to other parameters. METHODS A retrospective case series study was conducted at a tertiary referral center. The medical records of 47 patients diagnosed with primary sinonasal adenoid cystic carcinoma between 1984 and 2015 were retrospectively reviewed. The survival impact of the primary treatment modalities and the anatomic sites of tumor involvement were analyzed. RESULTS Cavernous sinus invasion was observed in 8 patients (17%), of whom 7 had ACC tumors originating from the maxillary sinus. The results of univariate analysis revealed that tumor stage, primary surgery, and the absence of skull-base and infratemporal fossa invasion were associated with better overall survival (P = 0.033, P = 0.012, P = 0.011, and P = 0.040, respectively) and better disease-free survival (P = 0.019, P = 0.001, P = 0.017, and P = 0.029, respectively). Multivariate analysis identified primary surgery as the only independent prognostic factor for disease-free survival (P = 0.026). Cavernous sinus invasion by sinonasal adenoid cystic carcinoma was not associated with worse overall survival or disease-free survival (P = 0.200 and P = 0.198, respectively). CONCLUSIONS Because maxillary adenoid cystic carcinoma is associated with a higher rate of cavernous sinus invasion, such cases warrant caution during preoperative planning. Primary surgery as the initial therapy provides better locoregional control and survival for patients with sinonasal adenoid cystic carcinoma. Cavernous sinus invasion did not significantly impact survival; thus, it should not be regarded as a contraindication for curative treatment.