Vila Jose, Gandini Sara, Gentilini Oreste
Division of Breast Surgery, European Institute of Oncology, Milan, Italy.
Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy.
Breast. 2015 Jun;24(3):175-81. doi: 10.1016/j.breast.2015.02.002. Epub 2015 Feb 23.
Young age is an independent risk factor for local recurrence after breast conserving surgery (BCS) and whole breast radiotherapy (WBRT) for breast cancer. The aim of this study was to carry out a systematic meta-analysis to address the issue as to whether type of surgery might have an impact on overall survival (OS) of young patients with early breast cancer.
We summarized six studies comparing OS between BCS + WBRT vs. mastectomy in young patients (≤40 years) with T1-T2 N0-N + M0 breast cancer. Primary endpoint was OS or distant metastasis free survival (DMFS). Only studies with fully adjusted Hazard Ratios (HR) were analyzed. Summary HRs were calculated through random effects models. We investigated publication bias and heterogeneity by means of sensitivity analyses and meta-regression models.
Five population-based studies and a pooled study of two clinical trials, for a total of 22598 patients 40 years old or younger, were considered: 10898 patients underwent BCS and 11700 underwent mastectomy. After all the adjustments, including nodal status and tumor size, no difference in risk of death was found between the two groups (10% not significant risk reduction in patients who underwent BCS compared to mastectomy; summary HR = 0·90; 95%CI: 0·81 to 1·00). Between-study heterogeneity was not statistically significant (I(2) = 34% and Chi-square P = 0·15). Heterogeneity investigation did not find any variable influencing results. No indication for publication bias was found (P-value = 0·37). Excluding the only study presenting DMFS the results did not change (HR = 0·88; 95%CI: 0·78 to 1·01).
Considering all the limitations, from the present meta-analysis carried out on 22598 patients it appears unlikely that mastectomy provides better OS compared to BCS + WBRT in early breast cancer patients aged 40 years or younger.
年轻是乳腺癌保乳手术（BCS）及全乳放疗（WBRT）后局部复发的独立危险因素。本研究旨在进行一项系统的荟萃分析，以探讨手术方式是否会对早期乳腺癌年轻患者的总生存期（OS）产生影响。
我们总结了六项比较BCS + WBRT与乳房切除术对年龄≤40岁、T1 - T2 N0 - N + M0乳腺癌年轻患者OS的研究。主要终点为OS或无远处转移生存期（DMFS）。仅分析具有完全调整风险比（HR）的研究。通过随机效应模型计算汇总HR。我们通过敏感性分析和荟萃回归模型研究发表偏倚和异质性。
共纳入五项基于人群的研究以及一项两项临床试验的汇总研究，总计22598例40岁及以下患者：10898例患者接受了BCS，11700例接受了乳房切除术。在进行包括淋巴结状态和肿瘤大小在内的所有调整后，两组之间未发现死亡风险差异（与乳房切除术相比，接受BCS的患者死亡风险降低10%，无统计学意义；汇总HR = 0·90；95%CI：0·81至1·00）。研究间异质性无统计学意义（I(2)=34%，卡方检验P = 0·15）。异质性研究未发现任何影响结果的变量。未发现发表偏倚迹象（P值 = 0·37）。排除唯一一项呈现DMFS的研究后，结果未改变（HR = 0·88；95%CI：0·78至1·01）。
考虑到所有局限性，基于对22598例患者进行的本次荟萃分析，对于40岁及以下的早期乳腺癌患者，乳房切除术似乎不太可能比BCS + WBRT提供更好的OS。
