Clinical Significance of Kinetics of Low-Density Lipoprotein Cholesterol and Its Prognostic Value in Limited Stage Small Cell Lung Cancer Patients

OBJECTIVES: To investigate the clinical significance of dynamic alteration of serum lipids in limited stage small cell lung cancer (LS-SCLC) patients and the risk that different lipid profiles poses to patients’ health. METHODS: We retrospectively analyzed the variation trends and prognostic values of serum lipids in 310 LS-SCLC patients who had received standard chemotherapy between 2002 and 2017. In addition to serum lipid level, which were measured at the time of pretreatment, after-chemotherapy and during disease progression and later analyzed, the dynamic lipid alteration trend and its correlation to progression-free survival (PFS) and overall survival (OS) were also statistically analyzed using Log-rank test and COX regression analyses. RESULTS: A significant decrease in HDL-C level was observed after standard chemotherapy (Post-CT baseline = −0.08 ± 0.34, P < 0.001), and this trend of reduction was further enhanced by thoracic radiotherapy (P = 0.046). Increase in LDL-C level was also observed to be associated with higher likelihood of disease progression (P = 0.003). Moreover, the extent of the increase in LDL-C was also associated with the number of progression sites, as patients with higher increase in LDL-C in exhibiting a progression at more than 2 sites outside thorax (P = 0.037). The patients’ median PFS and OS were 14.04 months (95%CI: 25.12-33.81) and 22.40 months (95%CI: 33.19-42.13), respectively. For both PFS and OS, LDL-C elevation remained an independent prognostic factor in the multivariate model (P = 0.007 and P = 0.022, respectively). CONCLUSION: Overall, for LS-SCLC patients, standard chemotherapy decreases the level of HDL-C, the level of increase in LDL-C could predict disease progression and even the number of progression sites, and LDL-C elevation could be an independent prognostic factor for poor OS and PFS.