A Meta-Analysis Of Randomized Controlled Trials Comparing Early And Late Concurrent Thoracic Radiotherapy With Etoposide And Cisplatin/Carboplatin Chemotherapy For Limited-Disease Small-Cell Lung Cancer

The aim of the present study was to determine the optimal time for concurrent thoracic radiotherapy (TRT) with etoposide and cisplatin/carboplatin (EP/EC) chemotherapy for the treatment of limited-disease small-cell lung cancer (LD SCLC). Randomized controlled trials comparing early and late concurrent TRT with EP/EC chemotherapy for the treatment of patients with LD SCLC were identified through searching databases such as MEDLINE, the Cochrane Central Register of Controlled Trials and Embase. Early thoracic radiotherapy (ERT) was defined as initiating irradiation within 30 days after chemotherapy initiation. A total of 3 eligible randomized controlled trials were identified. No significant differences in the objective response rate were detected between early and late concurrent TRT [risk ratio (RR)=1.01; 95% confidence interval (CI): 0.86-1.18; P=0.90]. Similar results were observed in the 1-, 2-, 3- and 5-year survival rates between early and late concurrent TRT (RR=1.06, 95% CI: 0.88-1.27, P=0.56; RR=1.15, 95% CI: 0.77-1.71, P=0.49; RR=0.90, 95% CI: 0.66-1.22, P=0.49;and RR=1.18, 95% CI: 0.64-2.16, P=0.60, respectively). The total incidence of grade 3-4 adverse events, including anemia, leukopenia, neutropenia, thrombocytopenia, nausea and vomiting, infection, esophageal toxicity, pulmonary toxicity, alopecia and hemorrhage with early concurrent TRT was significantly higher compared to that with late concurrent TRT (RR=1.21, 95% CI: 1.03-1.43, P=0.02). Thus, the results of our study indicated that the prognosis of LD SCLC treated with late concurrent TRT and EP/EC chemotherapy is similar to that with early concurrent TRT, although the incidence of grade 3-4 adverse events was lower in LD SCLC patients treated with late concurrent TRT combined with EP/EC chemotherapy.