Predictors of survival in parotid adenocarcinoma not otherwise specified: a National Cancer Database study of 3155 patients

Background Parotid adenocarcinoma not otherwise specified (PANOS) is a common parotid cancer, but studies specifically on this subject are limited. Methods We conducted a retrospective review of the National Cancer Database. Results Ten percent of all parotid cancers were PANOS ( n = 3155). Median age was 67 years. Most patients were men (62.8%) with high‐grade histology (67.2%). Regional metastasis was common (35.9%), whereas occult nodal metastasis (20.2% overall) was less frequent in non‐high‐grade lesions (8.5% vs 31.6%; p < .001). Distant metastasis was rare (7.9%). Five‐year overall survival (OS) was 47%. In multivariate analysis, age, regional metastasis, distant metastasis, high‐grade, and T classification were predictors of lower survival. Patients with stage III to IV disease receiving surgery and radiotherapy had a better OS than those receiving surgery alone (51% vs 41%; p < .001). Conclusion PANOS is an aggressive disease with frequent regional metastasis and low survival. Numerous variables are associated with worse survival. © 2016 Wiley Periodicals, Inc. Head Neck 38:1208–1212, 2016