Pre-treatment Body Mass Index as a Predictive Biomarker for Immunotherapy Outcomes in Advanced Lung Cancer

Abstract Objectives To analyze the clinicopathological parameters of advanced lung cancer patients who received Immune checkpoint inhibitors (ICIs) treatment to establish pre-treatment body mass index (BMI) as a predictor of immunotherapy response, patient survival, and immune-related adverse events (irAEs). Methods We retrospectively evaluated a cohort of 92 patients who received therapy with ICIs for advanced lung cancer at our hospital between January 2018 and January 2021. Patients were categorized into three groups based on BMI; an underweight group (BMI < 18.5 kg/m2), a normal-weight group (18.5 kg/m2 ≤ BMI ≤ 24.9 kg/m2), and an overweight group (BMI ≥ 25 kg/m2). The correlations were observed between BMI and immunotherapy response, progression-free survival (PFS), and irAEs based on ICIs treatment. Results Pretreatment BMI levels were significantly associated with response to ICIs therapy in disease control rate (DCR) (p = 0.034) and PFS (p = 0.006) of patients with advanced lung cancer, and it was a non-significant trend towards objective response rate (ORR) (p = 0.086). Pretreatment BMI, gender, and PD-L1 expression level were independent prognostic factors for PFS in univariate and multivariate analyses: HR = 0.323, 95% CI: 0.141–0.737, p = 0.007, and HR = 0.277, 95% CI: 0.115–0.670, p = 0.004; gender: HR = 2.609, 95% CI: 1.198–5.683, p = 0.016; PD-L1: HR = 6.599, 95% CI: 1.555–27.996, p = 0.001). Higher BMI is a significant predictor for irAEs (p = 0 .016). Conclusion High pre-treatment BMI is associated with positive immunotherapy outcomes, while decreased BMI was associated with irAEs development.