Impact of obesity on outcomes for patients with head and neck cancer

Objectives: The prognostic role of obesity in head and neck squamous cell carcinoma (HNSCC) is not well defined. This study aims to determine its effect on disease-specific outcomes such as recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) in addition to overall survival (OS). Methods: For patients with newly diagnosed HNSCC undergoing radiation therapy (RT) at a single institution, body mass index (BMI) at diagnosis was categorized as normal (18.5 to 24.9 kg/m²), overweight (25 to 29.9 kg/m²) and obese (≥30 kg/m²). Outcomes were compared by BMI group using Cox regression. Results: 341 patients of median age 59 (range, 20–93) who underwent curative RT from 2010 to 2017 were included. 58% had oropharynx cancer, 17% larynx and 15% oral cavity. 72% had stage IVA/B disease and 28% stage I-III. At diagnosis, 33% had normal BMI, 40% overweight, and 28% obese. 59% had definitive RT and 41% had postoperative RT. Alcoholic/smoking status, advanced tumor stage, hypopharynx/larynx tumors, and feeding tube placement were more common in patients with lower BMI (P <.05 for each). Median follow-up was 30 months (range, 3–91). Higher BMI was associated with improved OS (P <.05) and obesity was associated with longer RFS (P <.05) and DMFS (P <.05), but not LRRFS (P =.07) after adjusting for confounding variables. Conclusion: Being overweight/obese at the time of HNSCC diagnosis is an independent prognostic factor conferring better survival, while obesity is independently associated with longer time to recurrence, primarily by improving distant control.