Meta-analysis of postoperative adjuvant chemotherapy without radiotherapy in early stage non-small cell lung cancer

Abstract

Yuan-Yuan Chen,* Lin-Wei Wang,* Shu-Yi Wang, Bi-Bo Wu, Zhen-Meng Wang, Fang-Fang Chen, Bin Xiong Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan, Hubei, People’s Republic of China *These authors contributed equally to this work Background: Many clinical trials have confirmed that postoperative adjuvant therapy can prolong survival of non-small cell lung cancer. However, the efficiency of postoperative chemotherapy without radiotherapy is unclear, especially in early stage (stages I and II). We aimed to assess the effect of postoperative chemotherapy without radiotherapy in early stage patients.Methods: Databases and manual searches were adopted to identify eligible randomized control trials. Hazard ratio (HR) was used to assess the advantage of disease-free survival (DFS) and overall survival (OS) by fixed or random-effects models.Results: Fourteen trials with 3,923 patients were included based on inclusion criteria. Compared with surgery alone, postoperative chemotherapy significantly improved DFS and OS with HR of 0.71 (P=0.005) and 0.74 (P<0.00001), respectively. Subgroup analysis showed both cisplatin-based (HR: 0.75, P<0.0001) and single tegafur–uracil (UFT) chemotherapy (HR: 0.72, P=0.002) yielded significant survival benefits, but the latter did not improve DFS (HR: 1.04, P=0.81). Indirect treatment comparison showed cisplatin-based chemotherapy was superior to single UFT in DFS, but comparable in OS. The benefits of postoperative chemotherapy were maintained in patients in stage I (HR: 0.74, P<0.00001) and IB (HR: 0.74, P=0.0003), but not in stage IA, although the trend supported chemotherapy (HR: 0.76, P=0.43).Conclusion: This meta-analysis demonstrates that postoperative chemotherapy without radiotherapy improves survival of stage I–II, I, and IB non-small cell lung cancer patients, but not for IA. Meanwhile, efficacy of cisplatin-based chemotherapy is comparable to single UFT in OS, but better in DFS, which should be paid more attention in future clinical practice. Keywords: postoperative chemotherapy, disease-free survival, overall survival