Prognostic significance of performance status in patients with head and neck squamous cell carcinomas (HNSCC) receiving immune checkpoint monoclonal antibodies (ICmAB) in a single institution.

Abstract

e17506 Background: The anti-PD1/-PDL1 ICmABs can result in objective responses in some (13-20%) patients (pts) with HNSCC. We evaluated clinical factors that may predict oncologic outcomes. Methods: We identified pts who received an ICmAB at our institution and retrospectively collected demographic, tumor, treatment, progression, and survival data. The Kaplan Meier method was used to estimate survival. Log-rank and Wilcoxon tests were used to explore associations between clinical features and outcomes. Results: 55 pts received ICmAB in a clinical trial at our center from 8/2012 to 12/2016. The median age was 64 years, 13 (24%) were female, and 45 (82%) were white. ECOG Performance Status (PS) was 0 and 1 in 23 (42%) and 32 (58%) pts, respectively. 29 (53%) were current/former smokers who smoked a median of 20 (range 0-70) pack years. Primary sites included: oropharynx (OP) 31 (56%), oral cavity 9 (16%), nasopharynx 6 (11%), nasal cavity 3 (5%), hypopharynx (HP) 2 (4%), unknown (UK) 2 (4%), and skin 2 (4%). 28 (51%) were p16+, with the following primary sites: OP in 26, UK in 1, and HP in 1. 53 (96%) received prior curative intent therapy. A median of 2 (range 0-5) lines of systemic therapy (including curative intent) were given prior to ICmAB initiation, and 31 received an ICmAB as a single agent. There were 19 (35%) objective responses with 1 complete response, and 14 (25%) had stable disease. With a median follow-up of 12 months (m), the median overall survival (OS) was 15m (95% CI 11,47), and median time to progression was 4m (95% CI 2.2, 6.8). An ECOG PS of 0 vs 1 was associated with superior OS (36m vs 11m p = 0.001). Tobacco use, p16+ disease, single agent ICmAB vs. combination, number of lines of prior systemic therapy, or radiation therapy within 3m prior to ICmAB initiation did not appear to have a relationship with survival. Conclusions: A PS of 0 predicted for more favorable OS among HNSCC pts receiving ICmAB in this single center retrospective cohort. In contrast to data with chemotherapy, established prognostic markers (including p16+ and limited/no tobacco use) did not appear to impact survival.