Levitt S H, Aeppli D M, Nierengarten M E
Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota, Minneapolis 55455, USA.
Acta Oncol. 1995;34(6):839-44. doi: 10.3109/02841869509127194.
The purpose of this study was to examine the meaning of local control, especially on survival, in breast cancer patients treated by lumpectomy with or without radiotherapy. We analyzed the survival results of four major published randomized trials that compare conservation surgery with or without radiation using three different statistical approaches: p-values, confidence intervals, and Bayesian techniques. All four trials report statistically significant increased local control and improved survival for the irradiated patients. Survival based on p-values and confidence intervals shows statistical significance for long-term follow-up of the NSABP-B06 trial, but not for the other trials, probably because of small sample sizes and short follow-up. At 10 years, the overall survival rates for the NSABP-B06 were 65% and 71% for lumpectomy alone or with radiation respectively. Interpreted in a Bayesian framework, the expected advantage in 10-year survival was 6% (the mean of NSABP-B06 10-year survival) with an 83% probability that the 10-year survival difference may lie between 2% and 10%. An 85% probability that 3% of patients will survive at 10 years because of irradiation translates into a 30% reduction in annual odds of death several years after treatment in stage I good prognosis patients and 15% in stage I poor prognosis patients. Analysis of the randomized trials comparing lumpectomy with or without radiation indicate a clear improvement in survival for the irradiated patients associated with increased local control. Combination of improved survival with the reduced psychological and economic costs associated with local recurrence argues well for the inclusion of radiation for many breast cancer patients.
本研究的目的是探讨局部控制，尤其是对生存的意义，在接受保乳手术加或不加放疗的乳腺癌患者中。我们分析了四项主要的已发表随机试验的生存结果，这些试验使用三种不同的统计方法比较了保乳手术加或不加放疗的情况：p值、置信区间和贝叶斯技术。所有四项试验均报告，接受放疗的患者局部控制有统计学显著改善，生存情况也有所改善。基于p值和置信区间的生存情况显示，NSABP - B06试验的长期随访有统计学显著性，但其他试验没有，这可能是由于样本量小和随访时间短。在10年时，NSABP - B06试验中单纯保乳手术或加放疗的总生存率分别为65%和71%。在贝叶斯框架下解释，10年生存的预期优势为6%（NSABP - B06试验10年生存的均值），10年生存差异在2%至10%之间的概率为83%。在I期预后良好的患者中，85%的概率表明3%的患者因放疗在10年时存活，这意味着治疗后数年每年死亡几率降低30%，在I期预后不良的患者中降低15%。对比较保乳手术加或不加放疗的随机试验分析表明，接受放疗的患者生存情况有明显改善，且局部控制有所增加。生存改善与局部复发相关的心理和经济成本降低相结合，有力地支持了许多乳腺癌患者应接受放疗。
