Division of Breast and Melanoma Surgical Oncology, Department of Surgery, Mayo Clinic, Rochester, MN, USA.
Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA.
Ann Surg Oncol. 2022 Sep;29(9):5747-5756. doi: 10.1245/s10434-022-11871-z. Epub 2022 May 15.
Neoadjuvant chemotherapy (NAC) is standard for most triple-negative and human epidermal growth factor receptor 2 (HER2)+ breast cancers, and frequently downstages node-positive (cN+) disease, permitting omission of axillary dissection. In estrogen receptor (ER)+/HER2- disease, response rates are lower. Whether Ki67 is associated with axillary downstaging in ER+/HER2- disease is unknown.
With institutional review board approval, we queried our institutional database to identify all patients with primary ER+/HER2- biopsy-proven cN+ breast cancer treated with NAC followed by surgery from January 2012 to December 2021. Nodal pathologic complete response (pCR) rates were evaluated by pretreatment Ki67 and patient age.
315 patients (median age 50 years) were included. Nodal pCR rate was 24.8% (78/315) and was higher in patients aged < 50 years than ≥ 50 years (31.8% versus 17.7%, p = 0.004). Ki67 was available on 236 patients (74.9%). Median Ki67 was 29.0% (range 1-98%) and did not differ by age category (p = 0.23). Patients with nodal pCR had higher Ki67 (median 40.3% versus 25.0%, p < 0.001). Nodal pCR rates were 28.4% (Ki67 ≥ 20%) versus 8.1% (Ki67 < 20%) (p < 0.001). On multivariable analysis, Ki67 and age category were predictive of nodal pCR. Combining these two parameters together, nodal pCR rates in age < 50 years were 35.8% when Ki67 ≥ 20% versus 14.3% with Ki67 < 20% (p = 0.02). In contrast, for age ≥ 50 years, nodal pCR was 21.0% for Ki67 ≥ 20% versus 2.6% with Ki67 < 20% (p = 0.008).
In ER+/HER2- breast cancer, nodal downstaging with NAC is associated with age (< 50 years) and Ki67 (≥ 20%). Age and Ki67 should be considered for NAC decision-making and can identify patients with high rates of nodal downstaging (36%) who would benefit from NAC to enable axillary preservation.
新辅助化疗（NAC）是大多数三阴性和人表皮生长因子受体 2（HER2）+乳腺癌的标准治疗方法，常使淋巴结阳性（cN+）疾病降级，从而避免腋窝清扫。在雌激素受体（ER）+/HER2-疾病中，反应率较低。Ki67 是否与 ER+/HER2-疾病中的腋窝降级有关尚不清楚。
经机构审查委员会批准，我们查询了机构数据库，以确定 2012 年 1 月至 2021 年 12 月期间接受 NAC 治疗后行手术的原发性 ER+/HER2-活检证实的 cN+乳腺癌且有完整治疗记录的所有患者。通过治疗前 Ki67 和患者年龄评估淋巴结病理完全缓解（pCR）率。
共纳入 315 例患者（中位年龄 50 岁）。淋巴结 pCR 率为 24.8%（78/315），年龄<50 岁的患者高于年龄≥50 岁的患者（31.8%比 17.7%，p=0.004）。236 例患者（74.9%）的 Ki67 水平可获取。Ki67 的中位数为 29.0%（范围 1-98%），且与年龄类别无关（p=0.23）。淋巴结 pCR 的患者 Ki67 水平较高（中位数 40.3%比 25.0%，p<0.001）。淋巴结 pCR 率为 28.4%（Ki67≥20%）比 8.1%（Ki67<20%）（p<0.001）。多变量分析显示，Ki67 和年龄类别是淋巴结 pCR 的预测因素。将这两个参数结合在一起，年龄<50 岁的患者中，Ki67≥20%时淋巴结 pCR 率为 35.8%，Ki67<20%时为 14.3%（p=0.02）。相比之下，年龄≥50 岁的患者中，Ki67≥20%时淋巴结 pCR 率为 21.0%，Ki67<20%时为 2.6%（p=0.008）。
在 ER+/HER2-乳腺癌中，NAC 引起的淋巴结降级与年龄（<50 岁）和 Ki67（≥20%）相关。年龄和 Ki67 应考虑用于 NAC 决策，并可识别出淋巴结降级率较高（36%）的患者，这些患者从 NAC 中获益，能够实现腋窝保留。
