Patients with IIIA-pN2 non-small cell lung cancer (NSCLC) are a heterogeneous group, So this meta-analysis aimed to determine prognostic factors and compare different postoperative adjuvant therapies on survival.
MEDLINE, Embase, Web of Science were searched to identify relevant trials up to May 2017. Datas of univariate and multivariate analyses of prognostic factors for overall survival (OS) were extracted and calculated by hazard ratios (HR) and 95% confience intervals (95% CI). Pooled survival curves were constructed by Engauge Digitizer and RStudio.
Overall 26 trials comprising 11,384 patients were included. The subgroup analysis for OS indicated that increased age (HR 1.02, 95%CI 1.02-1.02, P < 0.00001), male (HR 1.37, 95%CI 1.25–1.49, P < 0.00001), increased pathologic T stage (HR 1.27, 95%CI 1.12–1.45, P = 0.0003), multiple N2 metastases (HR 1.53, 95%CI 1.34–1.74, P < 0.0001), positive of skip matestasis (HR 2.07, 95%CI 1.25–3.42, P < 0.0001), involvement of N1 nodal station (HR 1.42, 95%CI 1.13–1.70, P = 0.003), pneumonectomy (HR 1.42, 95%CI 1.16–1.73, P = 0.0007), increasing clinical T classification (HR 1.48, 95%CI 1.09–2.02, P = 0.01), increasing clinical N classification (HR 1.75, 95%CI 1.23–1.48, P = 0.002) were significantly associated with poor OS and N downstaging (HR 0.46, 95%CI 0.37–0.68, P < 0.0001), PORT (HR 0.76, 95%CI 0.64–0.72, P = 0.004), adjuvant chemotherapy (HR 0.69, 95%CI 0.56–0.85, P = 0.007) were significantly associated with better OS. The 5-year disease-free survival rate was 38.9% in postoperative chemoradiotherapy group and 29.5% in postoperative chemotherapy group (p = 0.001). Survival was improved in patients with pN2 disease who received postoperative radiotherapy, both in the chemotherapy (5-year survival rate, 65.3% vs. 49.3%) and observation arm (5-year survival rate, 53.3% vs. 32.3%).
The main prognostic factors were age, gender, clinical T stage, pathologic T stage, operation procedure, clinical N status, involved N2 stations, N1 nodes involved, N2 Skip metastasis, N downstaging, postoperative radiotherapy as well as adjuvant chemotherapy. And these should be considered as stratification factors for further trials.
Clinical trial identification
Legal entity responsible for the study
Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University.
China “863” Plan Project.
All authors have declared no conflicts of interest.