Survival effects of postmastectomy adjuvant radiation therapy using biologically equivalent doses: A clinical perspective
Survival effects of postmastectomy adjuvant radiation therapy using biologically equivalent doses: A clinical perspective
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DOI：
10.1093/jnci/djj002
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发表时间：
2006-01-04
影响因子：
10.3
通讯作者：
Langlands, AO
中科院分区：
文献类型：
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作者：
Gebski, V;Lagleva, M;Langlands, AO
背景乳腺切除术后放射治疗可减少可手术乳腺癌患者的局部复发，但是否能提高生存率一直存在争议。我们重新分析了36项无混杂试验的结果（即，放射治疗的添加是所比较的治疗之间的唯一判别因素），其在提供38项比较的先前荟萃分析中被鉴定。研究方法：我们对个体患者数据使用了三种预定义的治疗类别：1）生物等效剂量（BED）为40-60戈伊，分2-戈伊次，具有适当的靶体积，2）放射治疗剂量不足或过量，以及3）靶体积不适当。放射治疗对5年和10年生存率的影响在每个治疗类别中从13199例患者的队列中进行估计，如果这些数据不可用，则从已发表的生存曲线中进行估计。我们还使用这种分类来重新分析早期乳腺癌试验者协作组（EBCTCG）乳房切除术后研究的数据。在10年时，我们研究中的19项比较中有16项（84%）与EBCTCG报告的结果一致。所有统计检验均为双侧检验。结果：38个可用的比较中有25个使用了最佳和完整的放疗（即，第1类）。在这25项比较中，17项有5年数据，这些数据显示辅助放疗与生存率绝对增加2.9%相关（死亡的比值比[OR]= 0.87，95%置信区间[CI] = 0.79至0.96; P = 0.006）。13个1类试验有10年的数据，这些数据显示辅助放疗与生存率的统计学显著性绝对增加6.4%相关（死亡OR = 0.78，95%CI = 0.70 - 0.85; P <0.001）。在2类（死亡OR = 0.91，95% CI = 0.75 - 1.11）或3类（死亡OR = 0.97，95% CI = 0.61 - 1.55）试验中未观察到生存率的统计学显著变化。在33项EBCTCG研究中，第1类试验（低80%）的局部复发几率比第2类（低70%）或第3类（低64%）试验降低得更多（P-异质性<0.001）。1类试验中全因死亡的几率（低13%）也低于2类（高3%）或3类（高26%）试验（P-异质性= 0.01）。结论：采用最佳BED和靶体积的辅助放射治疗与长达10年的生存率改善在统计学上显著相关。
Background. Postmastectomy radiation therapy reduces locoregional recurrence among women with operable breast cancer, but whether it improves survival has been controversial. We reanalyzed the results from 36 unconfounded trials (i.e., addition of radiation therapy was the sole discriminant between treatments being compared) that were identified in previous meta-analyses, which provided 38 comparisons. Methods: We used three predefined treatment categories for individual patient data: 1) a biologically equivalent dose (BED) of 40-60 Gy in 2-Gy fractions with an appropriate target volume, 2) an inadequate or excessive dose of radiation therapy, and 3) an inappropriate target volume. Effects of radiation therapy on 5-year and 10-year survival in each of the treatment categories were estimated from a cohort of 13 199 patients from the published rates or, if these were unavailable, from the published survival curves. We also used this categorization to reanalyze data from Early Breast Cancer Trialists' Collaborative Group (EBCTCG) postmastectomy studies. At 10 years, 16 (84%) of the 19 comparisons in our study coincided with those reported by the EBCTCG. All statistical tests were two-sided. Results: Twenty-five of the 38 available comparisons had used optimal and complete radiotherapy (i.e., category 1). Of these 25 comparisons, 17 had 5-year data, and these data showed that adjuvant radiation therapy was associated with a 2.9% absolute increase in survival (odds ratio [OR] of death = 0.87, 95% confidence interval [CI] = 0.79 to 0.96; P = .006). Thirteen category 1 trials had data at 10 years, and these data showed that adjuvant radiation therapy was associated with a statistically significant 6.4% absolute increase in survival (OR of death = 0.78, 95% CI = 0.70 to 0.85; P < .001). No statistically significant change in survival was observed among category 2 (OR of death = 0.91, 95% CI = 0.75 to 1.11) or 3 (OR of death = 0.97, 95% CI = 0.61 to 1.55) trials. Among the 33 EBCTCG studies, odds of local recurrence were reduced more among category 1 trials (80% lower) than among category 2 (70% lower) or 3 (64% lower) trials (P-heterogeneity < .001). Odds of all-cause death were also lower among category 1 trials (13% lower) than among category 2 (3% tower) or 3 (26% higher) trials (P-heterogenity = .01). Conclusions: Adjuvant radiation therapy with an optimal BED and target volume was statistically significantly associated with improved survival for up to 10 years.