Prognostic Significance of Serum Lipids in Patients with Non-Small Cell Lung Cancer Treated with Radiotherapy: A Multicenter Prospective Study

Abstract

Although lipids have been assessed for their possible roles in cancer survival prediction, studies on the association between serum lipids levels and the prognosis of non-small cell lung cancer (NSCLC) patients are limited. This study aimed to evaluate whether serum lipids are associated with outcomes in patients with NSCLC treated with radiotherapy. We conducted a multicenter prospective study on patients diagnosed with NSCLC between January 2018 and February 2021. Participants received thoracic radiotherapy of 60ཞ80 Gy to the primary lung tumor and positive lymph node metastases. We measured patients' serum lipids levels (serum triglyceride, TGs; total cholesterol, TC, high density lipoprotein cholesterol, HDL-C; low density lipoprotein cholesterol, LDL-C) before radiotherapy. The association between serum lipids levels and overall survival (OS) was evaluated using hazard ratios. We sought to determine a threshold point using optimal stratification. Survival analysis was performed using Kaplan-Meier curves. Of the 300 participants diagnosed with NSCLC treated with radiotherapy, 165 (55.0%) were men. Median follow-up time was 24.4 months (range 1.0- 101.9 months). Using univariate and multivariate Cox proportional hazard analysis, among those serum lipids, only serum TG was shown to be independent prognostic factors for OS (hazard ratio: 1.203, 95% confidence interval: 1.038 - 1.393, p = 0.014). The cut-off for TG associated with OS was 2.04 mmol/L. Based on the TG cut-off value, 55 NSCLC patients were categorized into the high TG group (>2.04 mmol/L) and 245 in the low TG group (<2.04 mmol/L). The NSCLC patients in the low TG group exhibited higher OS than the high group (median OS, not reach vs 41.4 months, p = 0.025). TG levels were found to be a significant negative prognostic biomarker for OS in NSCLC patients treated with radiotherapy.