Obesity and Survival After Immune Checkpoint Inhibition for Head and Neck Squamous Cell Carcinoma

Importance For patients treated with immune checkpoint inhibitors (ICIs), recent data suggest that obesity has a beneficial effect on survival outcomes in various cancer types. Reports on this association in head and neck cancer are limited. Objectives To compare overall survival (OS) to 5 years and functional outcomes in patients with head and neck squamous cell carcinoma (HNSCC) treated with ICIs based on pretreatment body mass index (BMI). Design, Setting, and Participants This retrospective population-based cohort study used data obtained from the TriNetX Global Collaborative Network database to identify patients with HNSCC who received ICI treatment between January 1, 2012, and December 31, 2023, resulting in a total of 166 patients (83 with BMI of 20.0-24.9 [normal BMI] and 83 with BMI of ≥30.0 [obesity BMI]) after propensity score matching (PSM) for pretreatment medical comorbidities and oncologic staging. Exposure Normal BMI vs obesity BMI. Main Outcomes and Measures Overall survival and functional outcomes (dysphagia, tracheostomy dependence, and gastrostomy tube dependence) were measured to 5 years after ICI treatment and compared between patients with obesity BMI and normal BMI. Additional analyses compared OS and functional outcomes in the cohort with normal BMI and cohorts with overweight BMI (25.0-29.9) and underweight BMI (<20.0). Results Among the 166 patients included in the PSM analysis (112 men [67.1%]; mean [SD] age, 62.9 [15.4] years), obesity BMI was associated with significantly improved OS at 6 months (hazard ratio [HR], 0.54 [95% CI, 0.31-0.96]), 3 years (HR, 0.56 [95% CI, 0.38-0.83]), and 5 years (HR, 0.62 [95% CI, 0.44-0.86]) after ICI treatment, compared with patients with normal BMI. Obesity BMI was also associated with decreased risk of gastrostomy tube dependence at 6 months (odds ratio [OR], 0.41 [95% CI, 0.21-0.80]), 1 year (OR, 0.41 [95% CI, 0.21-0.78]), 3 years (OR, 0.35 [95% CI, 0.18-0.65]), and 5 years (OR, 0.34 [95% CI, 0.18-0.65]). Obesity was also associated with decreased risk for tracheostomy dependence at 1 year (OR, 0.52 [95% CI, 0.28-0.90]), 3 years (OR, 0.45 [95% CI, 0.45-0.90]), and 5 years (OR, 0.45 [95% CI, 0.45-0.90]). There were no differences in rates of dysphagia or immune-related adverse events between cohorts at any points. Conclusions and Relevance Using population-level data for patients with HNSCC treated with ICIs, these results suggest that having obesity was associated with improved 6-month, 3-year, and 5-year OS compared with having normal BMI. Additionally, obesity was associated with decreased gastrostomy and tracheostomy tube dependence compared with normal BMI. Further investigation is required to understand the mechanism of these findings.