Impact of BMI on the Survival Outcomes of non-Small Cell Lung Cancer Patients Treated with Immune Checkpoint Inhibitors: A Meta-Analysis

Objectives: ICIs have become the standard treatment for advanced NSCLC patients. Currently, PD-L1 is the most widely useful biomarker to predict ICI efficacy, but the sensitivity and specificity are limited. Therefore, the useful predictive biomarkers of ICI efficacy is urgently needed. BMI is an internationally used measure of body health. Obesity may affect ICI efficacy by changing T cell functions. This meta-analysis aimed to clarify the relationship between BMI and survival outcomes of NSCLC patients treated with ICIs. Methods: A systematic review was conducted to identify studies that assessed the association between BMI and survival outcomes in patients treated with ICIs. OS was the primary endpoint, and PFS was the secondary endpoint. Random-effect models or fixed-effect models were utilized to combine study effects according to the Cochran Q and I 2 tests. Results: Nine studies, including 4602 NSCLC patients treated with ICIs, that met the inclusion criteria were selected for this meta-analysis. There was no significant difference in PFS (HR 0.885; 95% CI 0.777–1.009, p  = 0.068) or OS (HR 0.947; 95% CI 0.789–1.137, p  = 0.560) between the low BMI group and the high BMI group. However, in the subgroup analysis, compared with normal-weight patients, overweight and obese patients achieved prolonged PFS (HR 0.862; 95% CI 0.760–0.978, p  = 0.021) and OS (HR 0.818; 95% CI 0.741–0.902, p ＜0.0001). Conclusion: Overweight and obese NSCLC patients tend to achieve prolonged survival time with ICI regimens. Further prospective studies are needed to strengthen the association between ICI outcomes and BMI levels.