Correlation analysis of serum cystatin C, uric acid and lactate dehydrogenase levels before chemotherapy on the prognosis of small-cell lung cancer

Related studies have reported that cystatin C (Cys C), uric acid (UA) and lactate dehydrogenase (LDH) affect tumor growth and invasion; however, the correlation between them and the prognosis of patients with small-cell lung cancer (SCLC) remains unclear. The present study aimed to investigate the effects of serum Cys C, UA and LDH concentrations on the prognosis of patients with SCLC prior to initial treatment, in order to identify potential targets for determining the clinical outcome of patients with SCLC. A total of 205 patients with SCLC were enrolled in the present study, and the clinical and laboratory data were obtained from the medical records. The receiver operating characteristic curve was used to determine the optimal cut-off values of Cys C, UA and LDH, while the Kaplan-Meier method was used for survival analysis. The Cox proportional hazard model was used for univariate and multivariate analyses to identify independent prognostic factors. The optimal cut-off values for Cys C, UA and LDH were 0.775 mg/l, 296.45 µmol/l and 198.5 U/l, respectively. The survival curves demonstrated that progression-free survival (PFS) and overall survival (OS) time were shorter in patients with high levels of Cys C, UA and LDH prior to chemotherapy. Univariate and multivariate analyses indicated that LDH concentration prior to chemotherapy may be an independent prognostic factor for both PFS and OS in patients with SCLC, while Cys C concentration may be an independent prognostic factor for PFS in patients with SCLC. The concentrations of Cys C, UA and LDH prior to chemotherapy were associated with prognosis of patients with SCLC. PFS and OS time were shorter, and the prognosis was poor in patients with elevated serum levels of Cys C, UA and LDH. Taken together, the results of the present study suggest that high concentrations of LDH and Cys C prior to chemotherapy may indicate rapid disease progression, thus it is important to focus on the progression and recurrence of the disease. High LDH concentration may also indicate a shorter survival time.