Abstract 949P
Background
Antibiotic (atx) use and dNLR (neutrophils/(leukocytes−neutrophils)) (dNLR) have been associated with worse outcome in patients (pts) treated with antiPD-1/PD-L1 agents across many tumor types. We investigated the prognostic value of these biomarkers in a cohort of R/M HNSCC pts treated with immunotherapy (IT).
Methods
Retrospective single institution analysis of R/M HNSCC pts treated with antiPD-1/PD-L1 alone or in combination with other IT or chemotherapy (CT) between 2015 and 2019. Data on atx use (30 days pre- up to 30 days post-IT start), clinical and baseline routine blood parameters, and objective response rate (ORR) by RECIST 1.1 were collected. Kaplan-Meier for overall survival (OS) and progression-free survival (PFS) were estimated and compared by log-rank test between atx (yes/no) and dNLR (>3/≤3). Multivariate analysis (MVA) were performed and hazard ratios (HR) and 95% confidence interval (IC) were reported.
Results
A total of 74 pts were evaluated: median age 58 years (range 51-64); 82.4% men. Recurrence site: locoregional/distant/both=45.9%/12.2%/41.9%; PD-L1>1%=32.4%; number of prior lines in R/M 0/≥1= 32.9%/67.1%. Treatment: antiPD-1/PD-L1 alone=44.6%, combo IT=51.4% and IT+ CT=4.1%; atx use 31,1%; dNLR ≤3/>3=66.2%/33.8%. Best ORR by atx use yes/no (%): complete response 13.6/0, partial response 18.2/17.7, stable disease 27.3/15.7, progression 40.9/66.7 (p=0.025). Median follow-up = 8.4 months (m) (range 3.5-19.4). Median OS and PFS did not differ by atx use yes vs no (4.8m vs 10.1m; p=0.71 and 2.1m vs 2.5m, p=0.43 respectively). OS and PFS were significantly higher in pts with baseline dNLR ≤3 vs >3 (11.4m vs 4.8m, p=0.013 and 2.5m vs 1.7m; p=0.038). In the MVA including atx, PD-L1 status, number of prior lines and site of recurrence, only dNLR> 3 was associated with both progression and death (HR 2.0; 95%CI: 1.1-3.7; p=0.024 for both).
Conclusions
Atx use in R/M HNSCC pts had a favourable impact on response rate, but not on OS and PFS in our cohort. After adjusting by atx use, baseline dNLR>3 remains strongly associated with worse OS and PFS. Derived NLR could be an easily-accessible tool to identify R/M HNSCC pts who benefit from IT treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.