Purpose: Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the most common breast cancer types. While they differ biologically and pathologically, their association with axillary lymph node (ALN) metastasis and survival remains unclear. This study compares the clinical features of ILC and IDC to evaluate ALN surgery considerations for ILC patients. Materials and Methods: We retrospectively analyzed 3543 patients who underwent upfront surgery for early breast cancer at Yonsei University Severance Hospital between January 2015 and December 2019. Multivariate logistic regression assessed factors linked to ALN metastasis, while Cox regression identified predictors of recurrence and survival. Results: Among the patients, 92.1% had IDC and 7.9% had ILC. T2-stage tumors were more prevalent in ILC (31.4% vs. 18.1%,p< 0.001). The rates of ALN metastasis were similar between the groups (IDC: 21.1%, ILC: 24.6%,p= 0.655); however, the presence of more than two metastatic ALNs was more frequent in ILC (9.6% vs. 5.0%,p= 0.004). Factors associated with having >2 metastatic ALNs included histology, suspicious axillary ultrasound, T stage, and lymphovascular invasion. The median follow-up period was 65 months, with no significant differences observed in 8-year recurrence-free survival (ILC: 95.2%, IDC: 94.1%,p= 0.134) or 5-year overall survival (ILC: 97.1%, IDC: 97.4%,p= 0.289). Conclusions: ILC features larger tumors and a higher nodal burden but has similar survival rates to IDC with proper treatment. Caution is essential in axillary surgery to avoid underestimating the nodal burden.
目的：浸润性导管癌（IDC）与浸润性小叶癌（ILC）是最常见的乳腺癌类型。尽管二者在生物学和病理学上存在差异，但其与腋窝淋巴结（ALN）转移及生存预后的关系尚不明确。本研究通过比较ILC与IDC的临床特征，以评估ILC患者腋窝淋巴结手术的考量因素。材料与方法：我们回顾性分析了2015年1月至2019年12月期间在延世大学Severance医院接受早期乳腺癌初始手术的3543例患者。采用多因素逻辑回归分析与ALN转移相关的因素，并通过Cox回归分析确定复发和生存的预测因子。结果：患者中IDC占92.1%，ILC占7.9%。T2分期肿瘤在ILC中更为常见（31.4% vs. 18.1%，p<0.001）。两组间ALN转移率相近（IDC：21.1%，ILC：24.6%，p=0.655）；然而，ILC中出现两个以上转移性ALN的情况更为频繁（9.6% vs. 5.0%，p=0.004）。与存在>2个转移性ALN相关的因素包括组织学类型、可疑腋窝超声表现、T分期以及淋巴血管侵犯。中位随访时间为65个月，两组在8年无复发生存率（ILC：95.2%，IDC：94.1%，p=0.134）和5年总生存率（ILC：97.1%，IDC：97.4%，p=0.289）方面均未观察到显著差异。结论：ILC具有肿瘤体积更大、淋巴结负荷更高的特点，但在适当治疗下其生存率与IDC相似。在腋窝手术中需格外谨慎，以避免低估淋巴结负荷。
肿瘤(癌症)患者之家