PDF(Pubmed)
Abstract：
Background This study was aimed at analyzing the impact of postoperative radiotherapy (PORT) after breast-conserving surgery (BCS) on Japanese patients with early-stage breast cancer and exploring the potential of PORT omission. Materials and methods Data from 794 patients with early-stage breast cancer (T1-2, N0-1), who underwent BCS with (n = 310) or without PORT (n = 484) were retrospectively analyzed. Local control (LC) rate and breast cancer-specific survival (BCSS) were compared between the groups that received and did not receive PORT in the whole cohort and low-risk cohort (i.e., the cohort with negative surgical margin, lymph node negativity, and estrogen receptor positivity, excluding young age of 49 or less), and in low-risk subgroup using propensity-score matching. Results PORT was associated with better LC but not BCSS in the total population. In the low-risk cohort, the incidence of local recurrence in patients without and with PORT was 5.3% and 4.8%, respectively, at 10 years (p = 0.591), and 7.8% and 4.8%, respectively, according to propensity-score matching (p = 0.485). Conclusion PORT improved LC in the total population, but not BCSS or overall survival (OS). In the low-risk group analysis (negative surgical margin, lymph node negativity, estrogen receptor positivity, and age 50 years or more), equivalent LC, BCSS, and OS were found including propensity-matched comparison. Therefore, this study showed that the omission of PORT could be a treatment option for low-risk Japanese patients. Further multi-center prospective studies are warranted to validate these findings and reduce the unnecessary burden of PORT for patients and institutions.
摘要：
背景本研究旨在分析保乳手术（BCS）后放疗（PORT）对日本早期乳腺癌患者的影响，并探讨PORT遗漏的可能性。材料和方法数据来自794例早期乳腺癌患者（T1-2，N0-1），对有（n=310）或无PORT（n=484）的BCS患者进行回顾性分析。在整个队列和低风险队列中接受和未接受PORT的组之间比较了局部控制（LC）率和乳腺癌特异性生存率（BCSS）（即，手术切缘阴性的队列，淋巴结阴性,和雌激素受体阳性，不包括49岁或以下的年轻人)，在低风险亚组中使用倾向得分匹配。结果在总人口中，PORT与更好的LC相关，但与BCSS无关。在低风险队列中，没有和有PORT的患者局部复发的发生率分别为5.3％和4.8％，分别,在10年(p=0.591)，7.8%和4.8%，分别,根据倾向评分匹配（p=0.485）。结论PORT改善了总人群的LC,但不是BCSS或整体生存（OS）。在低风险组分析中(阴性手术切缘，淋巴结阴性,雌激素受体阳性，年龄50岁或以上)，等效LC,BCSS,和OS被发现包括倾向匹配比较。因此,这项研究表明,对于日本低危患者,省略PORT可能是一种治疗选择.需要进一步的多中心前瞻性研究来验证这些发现，并减少PORT对患者和机构的不必要负担。
