The endoscopic endonasal approach for sinonasal and nasopharyngeal adenoid cystic carcinoma

Objective: To determine factors affecting outcomes for patients with sinonasal and nasopharyngeal adenoid cystic carcinoma (SNACC) treated using the endoscopic endonasal approach (EEA) with preservation of key structures followed by adjuvant radiotherapy (RT). Method: Retrospective case series of 30 patients treated at the University of Pittsburgh between 2000 and 2014. Hospital records were reviewed for clinical and pathologic data. Outcome measures included overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) rates. Results: The majority of patients had T4a and T4b disease (23.3%, and 63.3%). Microscopically positive margins were present in 21 patients (63.6%). Positive margins were present in nine patients (30.0%). The mean and median follow-up were 3.97 and 3.29 years. Five-year OS, DFS, LRFS, and DMFS were 62.66%, 58.45%, 87.54%, and 65.26%. High-/intermediate-grade tumors had worse DFS (P =.023), and LRFS (P =.026) (HR = 4.837, 95% CI, 1.181–19.812). No factors were associated with significantly worse DMFS. No patient suffered CSF leak, optic nerve, or internal carotid injury. The mean and median length of hospital stay was 4.1 days and 2.0 days (range: 0–32 days). Conclusion: Organ-preserving EEA with adjuvant RT for low-grade SNACC offers 5-year survival similar to that reported by other studies, which include radical, open skull base surgery. Patients with high-grade disease do poorly and may benefit from novel treatment strategies. For low-grade disease, organ-preserving EEA with RT may be the best option, offering a balance of survival, quality of life, and decreased morbidity for patients with this difficult-to-cure disease. Level of Evidence: 4 Laryngoscope, 130:1414–1421, 2020.