Meta-analysis of postoperative adjuvant chemotherapy without radiotherapy in early stage non-small cell lung cancer
the ONA take:
Postoperative adjuvant chemotherapy without radiotherapy improves survival of patients with stage I-II, I, and IB non-small cell lung cancer (NSCLC), but not for those with IA disease, a study published in the journal OncoTargets and Therapy has shown.
According to the American Cancer Society, the 5-year observed survival rates, which were calculated from the National Cancer Institute’s SEER database, for patients with stage IA, IB, IIA, and IIB NSCLC are 49%, 45%, 30%, and 31%, respectively.
For the meta-analysis, researchers at Zhongnan Hospital of Wuhan University in China sought to evaluate the effectiveness of postoperative chemotherapy without radiotherapy in patients with early stage NSCLC. Researchers analyzed data from 14 trials that included 3,923 patients with histologically confirmed stage I and/or II NSCLC who underwent radical resection and received surgery followed by chemotherapy or surgery alone.
Results showed that postoperative chemotherapy significantly improved disease-free survival and overall survival compared with surgery alone. Subgroup analyses demonstrated that postoperative chemotherapy was not beneficial in patients with stage IA disease, but there was a trend toward supporting the use of adjuvant chemotherapy.
Researchers also found that the efficacy of cisplatin-based regimens is comparable to single tegafu-uracil, an agent similar to 5-fluorouracil that is commonly used in the United States, in overall survival; however, cisplatin-based chemotherapy resulted in a better disease-free survival.
The findings suggest that further prospective clinical trials should be conducted to evaluate the efficacy of postoperative chemotherapy in patients with stage IA and II NSCLC.
OncoTargets and Therapy
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