Background and objective: Although evidence for a significant survival benefit of chest radiotherapy has been proven, no conclusion could be drawn regarding the optimal timing of chest radiation. The aim of this study is to explore whether the timing of chest radiation may influence the survival of the patients with limited-stage small-cell lung cancer (LSSCLC) by performing a literature-based meta-analysis.
Methods: By searching Medline, CENTRAL (the Cochrane central register of controlled trials), CBM, and CNKI, et al, we collected both domestic and overseas published documents about randomized trials comparing different timing chest radiotherapy in patients with LS-SCLC. Early chest radiation was regarded as beginning within 30 days after the start of chemotherapy. Random or fixed effect models were applied to conduct meta-analysis on the trials. The combined odds ratio (OR) and the 95% confidence interval (CI) were calculated to estimate the mortality in 2 or 3 years and toxicity of the two treatments. The statistical heterogeneity was determined by cochran's Chi-square test (Q test). The Begg' test was used to determine the publication bias.
Results: Six trials that included a total of 1 189 patients were analyzed in the meta-analysis 587 patients were in the early radiation group and 602 patients were in the late radiation group. Considering all 6 eligible trials, the overall survival at 2/3 years was not significantly different between early and late chest radiation (OR=0.78, 95%CI: 0.55-1.05, Z=1.68, P=0.093). For the toxicity, no obvious difference was observed for early chest radiotherapy compared with late irradiation in pneumonitis (OR=1.93, 95%CI: 0.97-3.86, P=0.797), esophagitis (OR=1.43, 95%CI: 0.95-2.13, P=0.572) and thrombocytopenia (OR=1.23, 95%CI: 0.88-1.77, P=0.746), respectively.
Conclusions: No statistical difference was observed in 2/3 years survival and toxicity, including pneumonitis, esophagitis and thrombocytopenia, between early radiation and late radiotherapy in LS-SCLC.
背景与目的: 研究结果显示序贯化放疗是小细胞肺癌主要的治疗手段，它可以提高患者的生存率，但是何时开始实施放疗仍然存在争议。本研究旨在探讨放疗实施时间对局限期小细胞肺癌预后的影响。
方法: 通过计算机检索Medline、CENTRAL(the Cochrane central register of controlled trials)、中国生物医学文献数据库系统(CBM)、中国期刊全文数据库(CNKI)等收集国内外公开发表的关于早期放疗(化疗开始后30天内开始放疗)对比后期放疗(化疗开始30天以后开始放疗)治疗局限期小细胞肺癌的随机对照研究。应用统计软件Stata 11.0进行数据分析。研究人群为局限期小细胞肺癌；干预措施为胸部放疗+化疗；结局指标为2/3年死亡率和放疗相关副反应。以优势比(odds ratio, OR)及相应的95%置信区间(confidence interval, CI)作为效应指标对结局进行比较。Q统计量的I2检验来检测各研究间的统计学异质性。双侧P＜0.05认为各研究间存在明显的异质性。采用Begg法对发表偏倚进行量化检测。
结果: 最终纳入分析的文章6篇，共1 189例患者，其中早期放疗组587例，后期放疗组602例。接受早期放疗与接受后期放疗相比，两者2/3年生存优势差别无统计学意义(OR=0.78, 95%CI: 0.55-1.05, P=0.093)；单独分析放疗性肺炎(OR=1.93, 95%CI: 0.97-3.86, P=0.797)疗性食管炎(OR=1.43, 95%CI: 0.95-2.13, P=0.572)相关血小板减少(OR=1.23, 95%CI: 0.88-1.77, P=0.746)差别均无统计学意义。
结论: 接受早期放疗与接受后期放疗相比，2/3年生存优势、放疗相关副反应无明显区别。