Abstract: Objective To explore the impact of sarcopenic obesity(SO) and chronic inflammation on the prognosis of the elderly patients with metastatic driver gene-negative non-small cell lung cancer(NSCLC). Methods A total of 99 elderly patients with metastatic driver gene-negative NSCLC treated at Department of Oncology of the First Affiliated Hospital with Nanjing Medical University and Geriatric Hospital of Nanjing Medical University from January 2020 to December 2022 were enrolled retrospectively. The patients were divided into SO group and non-SO group according to the result of CT body composition analysis. The first-line treatment regimen consisted of platinum-based doublet chemotherapy plus immunotherapy. Chronic inflammation was assessed using the fibrinogen-to-albumin ratio(FAR). Median progression-free survival (mPFS), median overall survival (mOS), FAR, and adverse reactions were compared between the groups. Results In SO group and non-SO group, mPFS was 7.0 months (95%CI:6.7-7.3) and 10.2 months (95%CI:8.9-11.5), and mOS was 12.0 months (95%CI:10.1-13.9) and 18.2 months (95%CI:14.2-22.2) respectively. Both mPFS and mOS in SO group were significantly lower than those in non-SO group(P＜0.05) .FAR was 0.090(0.079-0.098) and 0.060(0.050-0.068) in SO group and non-SO group, respectively (P＜0.001). High FAR was present in 18.4% (9 cases) of SO group and 4.0% (2 cases) in non-SO group. The proportion of chemotherapy intensity reduced to <50% of standard due to adverse reactions in SO group was significantly higher than that in non-SO group(49.0% vs 20.0%, P＜0.05). Conclusions SO may induce chronic low-grade inflammation, which is associated with poor treatment tolerance and prognosis in the elderly patients with metastatic driver gene-negative NSCLC.

Key words: sarcopenic obesity, chronic inflammation, aged, non-small cell lung cancer