Role of thoracic radiotherapy in extensive stage small cell lung cancer: a systemic review and meta-analysis

Ao-Mei Li; Han Zhou; Yang-Yang Xu; Xiao-Qin Ji; Tian-Cong Wu; Xi Yuan; Chang-Chen Jiang; Xi-Xu Zhu; Ping Zhan; Ze-Tian Shen

doi:10.21037/atm-20-5765

Role of thoracic radiotherapy in extensive stage small cell lung cancer: a systemic review and meta-analysis

Ann Transl Med. 2021 Feb;9(4):299. doi: 10.21037/atm-20-5765.

Authors

Ao-Mei Li¹, Han Zhou¹, Yang-Yang Xu², Xiao-Qin Ji¹, Tian-Cong Wu¹, Xi Yuan¹, Chang-Chen Jiang¹, Xi-Xu Zhu¹, Ping Zhan^{2

3}, Ze-Tian Shen¹

Affiliations

¹ Department of Radiation Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
² Department of Respiratory and Critical Care Medicine, Jinling Hospital, Nanjing Medical University, Nanjing, China.
³ Department of Respiratory and Critical Care Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.

Abstract

Background: The role of thoracic consolidation radiotherapy in patients with extensive stage small cell lung cancer (ES-SCLC) remains controversial. This study aimed to evaluate the efficacy of thoracic radiotherapy (TRT) in these patients.

Methods: A systematic literature search was performed in PubMed, Embase, and the Cochrane library to identify qualified clinical studies. The hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS), progression-free survival (PFS) and local recurrence-free survival (LRFS) were extracted, and toxicity of the TRT group versus non-TRT group was analyzed.

Results: A total of 12 studies were included in this meta-analysis, including 936 patients in the TRT group and 1,059 patients in the non-TRT group. The combined results showed that TRT significantly improved OS (HR =0.65; 95% CI: 0.55-0.77, P<0.00001), PFS (HR =0.64; 95% CI: 0.56-0.72, P<0.00001) and LRFS (HR =0.38, 95% CI: 0.26-0.53, P<0.00001). Subgroup analysis showed that OS benefits were observed in patients receiving sequential TRT (HR =0.67; 95% CI: 0.54-0.84, P=0.0006). The addition of TRT significantly improved OS in patients over 65 years of age (HR =0.55; 95% CI: 0.40-0.74, P=0.0001). For patients with only one organ metastasis, there was no significant difference in OS between the two groups (HR =0.61; 95% CI: 0.36-1.01, P=0.06). There was no statistical difference in hematologic toxicity (leukopenia, thrombocytopenia, anemia) and non-hematologic toxicity (nausea or vomiting) between the two groups. The incidence of grade ≥3 esophageal toxicity was 4.6% in the TRT group and 0% in the non-TRT group (P=0.0001). Grade ≥3 bronchopulmonary toxicity was 2.9% in the TRT group and 0.8% in the non-TRT group (P=0.02).

Conclusions: TRT improves OS, PFS and LRFS in patients with ES-SCLC, with a low increase in esophageal and bronchopulmonary toxicity. More randomized controlled trials (RCTs) are expected to confirm our conclusions.

Prospero registration number: CRD42020190575.

Keywords: Small cell lung cancer (SCLC); meta-analysis; thoracic radiotherapy (TRT).