Effectiveness of neoadjuvant chemotherapy on the survival outcomes of patients with resectable non-small-cell lung cancer: A meta-analysis of randomized controlled trials

Purpose: To determine the effectiveness of neoadjuvant chemotherapy (NACT) versus primary surgery on survival outcomes for resectable non-small-cell lung cancer (NSCLC) using an approach based on a meta-analysis. Methods: The PubMed, EmBase, Cochrane library, and CNKI databases were systematically browsed to identify randomized controlled trials (RCTs) which met a set of predetermined inclusion criteria throughout January 2020. Hazard ratios (HRs) were applied for the pooled overall survival (OS) and progression-free survival (PFS) values, and the pooled survival rates at 1-year and 3-year were used as the relative risk (RR). All the pooled effect estimates with 95% confidence intervals (CIs) were calculated using the random-effects model. Results: Nineteen RCTs contained a total of 4372 NSCLC at I-III stages was selected for final meta-analysis. We noted NACT was significantly associated with an improvement in OS (HR: 0.87; 95%CI: 0.81-0.94; P < 0.001) and PFS (HR: 0.86; 95%CI: 0.78-0.96; P = 0.005). Moreover, the survival rate at 1-year (RR: 1.07; 95%CI: 1.02-1.12; P = 0.007) and 3-year (RR: 1.16; 95%CI: 1.06-1.27; P = 0.001) in the NACT group was significantly higher than the survival rate for the primary surgery group. Finally, the treatment effects of NACT versus primary surgery on survival outcomes might be different when stratified by the mean age of patients and the tumor stages. Conclusions: NACT could improve survival outcomes for patients with resectable NSCLC, suggesting its suitable future applicability for clinical practice. However, large-scale RCT should be conducted to assess the chemotherapy regimen on the prognosis of resectable NSCLC.