Does adding thoracic radiation therapy to systemic chemotherapy increase 1-year and 2-year overall survival in patients with extensive-stage small-cell lung cancer? meta-analysis.

BACKGROUND

Lung cancer is the leading cause of cancer-related mortality worldwide. Approximately 15-20% of newly diagnosed individuals with primary lung cancer have small cell lung cancer, and more than 60% of patients have advanced-stage small cell lung cancer at the time of diagnosis. Patients with advanced-stage small-cell lung cancer may benefit from thoracic radiation therapy. This comprehensive meta-analysis was conducted to determine whether adding thoracic radiation to systemic chemotherapy increases 1-year and 2-year survival in patients with advanced-stage small-cell lung cancer.

METHODS

The Science Direct, PubMed, Embase, and Wanfang databases were comprehensively searched from 1980 to 2022. The inclusion criteria for studies were as follows: (1) all patients had advanced-stage small cell lung cancer; (2) a group receiving thoracic radiation therapy combined with chemotherapy was compared with a group receiving only chemotherapy; and (3) 1-year and 2-year overall survival data were provided. Pooled relative risks (RRs) and risk differences (RDs) were calculated, publication bias was evaluated, and sensitivity analysis was conducted.

RESULTS

Ten studies met the inclusion criteria. These studies included 922 patients (534 patients in the chemotherapy combined with thoracic radiation therapy (ChT/TRT) group and 388 patients in the chemotherapy (ChT) group). The results of the meta-analysis revealed that the addition of thoracic radiotherapy to chemotherapy increased the 1-year overall survival rate to 52%, whereas the 1-year overall survival rate was 32.2% when chemotherapy alone was used. The addition of thoracic radiotherapy to chemotherapy also increased the 2-year survival rate to 18.7%, compared with 10% in the ChT group. The ChT/TRT group had a significantly better 1-year overall survival rate than the ChT group, with a pooled RR of 1.61 (95% CI, 1.36-1.90, P < 0.00001) and a pooled RD of 0.2 (95% CI, 0.13-0.26, P < 0.00001). The ChT/TRT group also had a significantly better 2-year overall survival rate than the ChT group, with a pooled RR of 1.90 (95% CI, 1.34-2.68, P = 0.0003) and a pooled RD of 0.09 (95% CI, 0.05-0.13, P < 0.0001).

CONCLUSION

This study revealed that adding thoracic radiation therapy to chemotherapy increases both 1-year and 2-year survival in patients with extensive-stage small-cell lung cancer.