Prognostic effect of body mass index in patients with advanced NSCLC treated with chemo-immunotherapy combinations

Introduction: It has been recognised that increasing body mass index (BMI) is associated with improved outcome from immune checkpoint inhibitors (ICI) in patients with various malignancies including NSCLC. However, it is unclear whether baseline BMI may influence outcomes from first-line chemo-immunotherapy combinations. Methods: In this international multicentre study we evaluated the association between baseline BMI, progression free survival (PFS) and overall survival (OS) in a cohort of patients with stage IV NSCLC consecutively treated with first-line chemo-immunotherapy combinations. BMI was categorized according to World Health Organization criteria. Results: Among the 853 included patients, 5.3% were underweight, 46.4% were of normal weight, 33.8% were overweight and 14.5% were obese. Overweight and obese patients were more likely aged ≥70 years (p=0.00085), never smokers (p<0.0001), with better baseline ECOG-PS (p=0.0127), lower prevalence of CNS (p=0.0002) and liver metastases (p=0.0395). Univariable analyses showed a significant difference in the median OS across underweight (15.5 months), normal weight (14.6 months), overweight (20.9 months) and obese (16.8 months) patients (log-rank for trend: p = 0.131), whilst no difference was found with respect to the median PFS (log-rank for trend: p = 0.510). Neither OS nor PFS were significantly associated with baseline BMI on multivariable analysis. Conclusions: In contrast to what observed in the context of chemotherapy free ICI-based regimens, baseline BMI does not affect clinical outcomes from chemo-immunotherapy combinations in patients with advanced NSCLC