5532 Background: Although extracapsular extension (ECE) is a known poor prognostic factor in head and neck squamous cell carcinoma (HNSCC) and recommended to be collected by the current AJCC manual, it currently does not influence the final stage. We evaluated the prognostic impact of ECE in 4 primary sites. Methods: The Surveillance Epidemiology and End Results (SEER) was queried for patients with squamous cell cancers of the oral cavity (OC), oropharynx (OP), hypopharynx (H) and larynx (L), known ECE status, M0, and diagnosed between 2004 and 2007. Survival curves were estimated by the Kaplan-Meier and compared by Cox proportional hazards models. Results: There were 23,384 patients meeting eligibility criteria, including 14,664 (62.7%) N0, 6483 (27.7%) N+ without ECE (NECE), and 2237 (9.6%) with ECE. ECE was associated with decreased 3-year overall survival (OS), compared to NECE, for all lymph node stages including N1 (52% vs 61%, HR 1.32, p = 0.001), N2a (60% vs 76%, HR 1.82, p<0.001), N2b (44% vs 62%, HR 1.62, p<0.001), N2c (34% vs 47%, HR 1.43, p<0.001), N3 (31% vs 44%, HR 1.38, p=0.012). ECE was also an independent poor prognostic factor for cancer in the OC (HR 1.43, p < 0.001), OP (HR 1.44, p < 0.001), H (HR 1.58, p = 0.01), and L (HR 1.28, p = 0.01). The comparison between ECE and NECE with one additional N degree showed no significant OS difference, except OP N1 and H N2a ECE, where survival was inferior to OP N2a and H N2b NECE respectively (Table). Conclusions: ECE is a significant predictor for poor outcomes in HNSCC, with survival equivalent to one additional degree of N involvement. [Table: see text]
Predictors of Extracapsular Extension in Patients With Squamous Cell Carcinoma of the Head and Neck and Outcome Analysis
