Association between obesity, sex, medical comorbidities, and survival in cancer patients treated with immune checkpoint inhibitors.

Abstract

Background: Obesity's impact on cancer treatment outcomes is poorly understood, especially in the context of immuno-oncology. This study explores how obesity and medical comorbidities are associated with overall survival in cancer patients receiving immune checkpoint inhibitors (ICIs). Additionally, considering the influence of sex on body composition in obesity, this study examines the relationship between sex, obesity, medical comorbidities, and survival.

Methods: This cohort study involved 688 patients with metastatic cancer received ICIs as first- or second-line therapy. Obesity was assessed using body mass index (BMI). Cox proportional hazard models and Kaplan-Meier survival analysis were used to examine associations between predictors and overall survival.

Results: Patients with higher BMI had longer overall survival, and hazard ratio (HR) for death was 0.83 (95% CI 0.73-0.95) for every 10 units increased in BMI. Additionally, patients belonged to the highest BMI group (≥ 40) had the lowest risk of death when comparing to patients with BMI 18.5 to < 30 with HR 0.58 (95% CI 0.37-0.90). In subgroup analysis, a significant association between high BMI and decreased HR for death was predominantly observed in the male cohort. In multivariate analysis, the prognostic value of BMI remained significant after adjusting for performance status, line of therapy, age-adjusted medical comorbidities, and cancer type.

Conclusions: Obesity was associated with decreased mortality risk for cancer patients who had received ICIs. There could be a sex-dependent association between survival benefit and obesity.