The efficacy of postoperative radiotherapy for patients with non-small cell lung cancer: An updated systematic review and meta-analysis

The controversy over the efficacy of postoperative radiotherapy (PORT) has existed for a long time. The present study reassessed the overall survival (OS) and disease-free survival (DFS) data to investigate whether PORT can improve survival in resectable non-small cell lung cancer (NSCLC) patients. The following databases were used to perform literature search: PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Embase (from January 1, 1986 to July 5, 2021). The results of overall survival (OS) and disease-free survival (DFS) were calculated as hazard ratio (HR). Confidence intervals are chosen with 95% confidence intervals. A total of 12 RCTs and 19 retrospective cohort studies were found to meet the inclusion criteria. A significant DFS improvement was detected in the PORT group (4111 patients from 15 studies), although statistical difference was not detected for OS between the non-PORT and PORT groups (31 studies, 49,342 total patients). PORT prolonged OS in patients undergoing PORT plus postoperative chemotherapy (POCT) and in pN2 patients. Patients with a median radiation dose of 50.4 Gy and a median radiation dose of 54 Gy had a better OS after PORT. However, if the total radiotherapy dose went up to 60 Gy, PORT increased the risk of death in NSCLC patients. Significant difference in OS was not found in the results of studies with regard to treatment methods, pathologic stages, study type, radiation beam quality, and radiation dose. Patients undergoing postoperative chemoradiotherapy and pN2 patients can benefit from PORT. Patients exposed to median radiation doses of 50.4 and 54 Gy demonstrated relatively good efficacy. For patients with non-small-cell lung cancer, PORT has not been proven to extend OS, but its effect on DFS remains strong.