Search

e18027 Background: Response rates of immune checkpoint inhibitor (ICI) therapy for recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC) are relatively low. This study evaluates the predictive and prognostic value of weight loss and changes in body composition prior to and during ICI therapy in R/M HNSCC. Methods: This retrospective multicenter cohort study enrolled ninety-eight patients. Patient, tumor and treatment characteristics were retrieved from health records, including neutrophil and platelet-lymphocyte-ratio (NLR and PLR). Cachexia was defined according to the international consensus (Fearon et al. 2011). Skeletal muscle (SM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were evaluated on baseline and follow-up computed tomography scans at the third lumbar vertebrae level. Univariable and multivariable regression analysis were performed for six months progression free survival (PFS6m) and overall survival (OS). Results: Thirty-four patients (35%) experienced significant early weight loss (> 2%) during the first six weeks of therapy. This subgroup presented a significantly higher NLR and PLR at baseline. NLR and PLR were significantly correlated with VAT and SAT index. Independent predictors of PFS6m were lower world health organization performance status (WHO PS) (HR 0.16 [95% CI 0.04-0.54] p = 0.003), higher baseline SAT index (HR 1.045 [95% CI 1.02-1.08] p = 0.003), and early weight loss < 2% (HR 0.85 [95% CI 0.74-0.98] p = 0.03). WHO PS and baseline cachexia in combination with > 2% early weight loss were independent predictors of OS (HR 2.09 [95% CI 1.11-3.92] p = 0.02, HR 2.18 [95% CI 1.13-4.21] p = 0.02). Conclusions: The combination of cachexia at baseline and weight loss during the first six weeks of ICI therapy is associated with worse OS in HNSCC patients treated with ICI therapy. Patients with early weight loss during ICI treatment show an increase in systemic inflammation. The mechanism of how adipose tissue interferes with ICI response needs further investigation.

e18503 Background: The prognosis for recurrent or metastatic Squamous Cell Carcinoma of Head and Neck (HNSCC) remains dismal and its treatment poses a challenge for oncologists. Agents against programmed cell death ligand 1 (PD-L1) have shown beneficial effects on overall survival (OS) for HNSCC. The aim of the present study was to compare differential effects of PD-L1 inhibitors on recurrent and metastatic HNSCC. Methods: In an indirect comparison of patients with recurrent HNSCC were matched to patients with metastatic HNSCC. All patients were treated with PD-L1 inhibitors at the general medical oncology department of UZ Leuven. Kaplan-Meier methods and Cox regression models were used to calculate the overall survival. Results: From December 2013 to July 2019, 68 patients with metastatic and 59 with recurrent HNSCC were enrolled and evaluable. A significant difference in OS was found between recurrent and metastatic groups (p < 0.02). The mean OS was 7.6 months (95% CI: 2.4-11.3 months) for the recurrent group, while in the metastatic group the mean OS was 13.7 months (95% CI: 5.7-16 months). Conclusions: As a second-line therapy, PD-L1 inhibitors were associated with longer overall survival in metastatic compared to recurrent HNSCC.