Impact of cholesterolemia and body mass index on outcome of metastatic non small cell lung cancer treated with immunotherapy.

Abstract

e20691 Background: Immunotherapy (IO) is effective against metastatic Non Small Cell Lung Cancer (mNSCLC). Nonetheless, a minority of patients (pts) gains a benefit from IO and predictive variables of response are scarcely understood. Previous retrospective studies have showed a superior outcome for obese pts and preclinical data suggest a role of lipid profile. We aimed at investigating these topics in a cohort of pts with mNSCLC. Methods: We retrospectively collected data about all consecutive pts with mNSCLC treated with IO at our Institution between 12/2017 and 12/2018. Body Mass Index (BMI) was calculated as weight/height2; pts were classified as overweight if having a BMI≥25 kg/m2. Basal Cholesterolemia (BC) was dosed between one month (mo) before and one mo after the beginning of IO, with a cut-off for normality of 200 mg/dL. Survival was estimated with Kaplan-Meier method. Cox model was used for multivariate analyses. Results: We identified 55 pts. Thirty-three had a normal baseline BMI, the remaining were overweighted. Median BC was 171.5 mg/dL (range 15-313); 14 pts had hypercholesterolemia. No correlation was evident between BMI and BC ( p .1772). Neither BMI nor BC were associated to first and best response to IO. Median Progression Free Survival (PFS) was 3.75 mos; median Overall Survival (OS) was 6.78 mos. Hypercholesterolemia was related to longer PFS (9.44 vs 3.71 mos, p .0484), confirmed at multivariate analysis ( p.0392). Both hypercholesterolemia and BMI≥25 kg/m2 were associated to longer OS (15.56 vs 5.13 mos, p.0411, and 16.67 vs 4.97 mos, p.0222, respectively), but only BMI retained significance at multivariate analysis ( p .0279). Conclusions: Hypercholesterolemia shows a positive impact on outcome of mNSCLC treated with IO. The independence of this correlation from BMI suggests the existence of a true different metabolic pathways. Moreover, overweight patients have a longer OS than those with normal BMI. This result confirms previous data on obese patients, extending the range of BMI values that are linked to a better prognosis. In conclusion, the role of metabolism and body composition in defining the benefit from IO in mNSCLC is likely multifaceted, warranting further investigation.