Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.
Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
Cancer Res Treat. 2023 Apr;55(2):592-602. doi: 10.4143/crt.2022.998. Epub 2022 Oct 11.
The utility of postmastectomy radiation therapy (PMRT) for breast cancer patients after neoadjuvant chemotherapy (NAC) is highly controversial. This study evaluated the impact of PMRT according to pathologic nodal status after modern NAC.
We retrospectively reviewed 682 patients with clinical stage II-III breast cancer who underwent NAC and mastectomy from 2013 to 2017. In total, 596 patients (87.4%) received PMRT, and 86 (12.6%) did not. We investigated the relationships among locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), overall survival (OS), and various prognostic factors. Subgroup analyses were also performed to identify patients who may benefit from PMRT.
The median follow-up duration was 67 months. In ypN+ patients (n=368, 51.2%), PMRT showed significant benefits in terms of LRRFS, DFS, and OS (all p < 0.001). In multivariate analyses, histologic grade (HG) III (p=0.002), lymphovascular invasion (LVI) (p=0.045), and ypN2-3 (p=0.02) were significant risk factors for poor LRRFS. In ypN1 patients with more than two prognostic factors among luminal/human epidermal growth factor receptor-2-negative subtype, HG I-II, and absence of LVI, PMRT had no significant effect on LRRFS (p=0.18). In ypN0 patients (n=351, 48.8%), PMRT was not significantly associated with LRRFS, DFS, or OS. However, PMRT showed better LRRFS in triple-negative breast cancer (TNBC) patients (p=0.03).
PMRT had a major impact on treatment outcomes in patients with residual lymph nodes following NAC and mastectomy. Among ypN0 patients, PMRT may be beneficial only for those with TNBC.
新辅助化疗（NAC）后乳腺癌患者行乳腺癌根治术后放疗（PMRT）的作用存在较大争议。本研究旨在评估现代 NAC 后根据病理淋巴结状态行 PMRT 的影响。
我们回顾性分析了 2013 年至 2017 年期间接受 NAC 和乳腺癌根治术的 682 例临床 II-III 期乳腺癌患者。共有 596 例（87.4%）患者接受了 PMRT，86 例（12.6%）患者未接受 PMRT。我们研究了局部区域无复发生存率（LRRFS）、无病生存率（DFS）、总生存率（OS）与各种预后因素之间的关系。还进行了亚组分析，以确定可能从 PMRT 中获益的患者。
中位随访时间为 67 个月。ypN+患者（n=368，51.2%）中，PMRT 在 LRRFS、DFS 和 OS 方面均有显著获益（均 p<0.001）。多因素分析显示，组织学分级（HG）III（p=0.002）、脉管侵犯（LVI）（p=0.045）和 ypN2-3（p=0.02）是 LRRFS 不良的显著危险因素。在 luminal/人表皮生长因子受体-2 阴性型 ypN1 患者中，若存在两个以上预后因素（包括 HG I-II 和无 LVI），则 PMRT 对 LRRFS 无显著影响（p=0.18）。ypN0 患者（n=351，48.8%）中，PMRT 与 LRRFS、DFS 或 OS 无显著相关性。然而，PMRT 使三阴性乳腺癌（TNBC）患者的 LRRFS 获益（p=0.03）。
NAC 和乳腺癌根治术后，残留淋巴结患者行 PMRT 对治疗结局有重大影响。在 ypN0 患者中，PMRT 可能仅对 TNBC 患者有益。
