Department of Breast Surgery, the Second Affiliated Hospital of Zhejiang, University School of Medicine, Hangzhou, Zhejiang Province, China.
Department of Pathology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
BMC Cancer. 2023 Sep 8;23(1):841. doi: 10.1186/s12885-023-11368-2.
Breast cancers with 1-10% cell staining for estrogen receptor (ER) present particular clinical features. The clinical data of estrogen receptor expression level and treatment effect are limited, particularly regarding chemotherapy benefit. We evaluated the pathologic response to neoadjuvant chemotherapy (NAC) in ER low positive tumors (ER staining 1-10%) and compared it with ER > 10% positive tumors (ER staining > 10%) and ER-negative tumors. We further explored the differences in recurrence and survival with respect to the ER expression level.
Patients with stages II and III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery were categorized according to their ER percentages into three groups: ER-negative, ER low positive, and ER > 10% positive. Logistic regression models were used to assess the association between each variable and pathologic complete response (pCR). Kaplan‒Meier analysis was used to estimate survival outcomes. Cox models were used to adjust for patient and tumor characteristics.
A total of 241 patients were analyzed. Of all patients included, 22 (9.1%) had ER low positive tumors, 159 (66.0%) had ER > 10% positive tumors, and 60 (24.9%) were ER-negative. Low ER positivity was significantly associated with a higher pCR rate than ER > 10% positivity (OR, 0.249; 95% CI, 0.067-0.923; P = 0.038). After a median follow-up time of 32 months, the disease-free survival (DFS) and overall survival (OS) of the patients with ER low positive tumors were significantly worse than those of the patients with ER > 10% positive tumors but similar to those with ER-negative tumors. After adjustment for covariates, ER low positive tumors were significantly associated with worse DFS than ER > 10% positive tumors.
Our results indicated that ER low positive breast cancer presents a better response to neoadjuvant chemotherapy and significantly worse prognosis for patients than those with ER > 10% positive tumors, but similar to the ER-negative group. These data support that this category of patients behaves clinically like patients with ER-negative breast cancer and should be treated differently from patients with ER > 10% positive tumors. Further prospective study is needed.
雌激素受体（ER）阳性率为 1%-10%的乳腺癌具有特殊的临床特征。目前关于 ER 低表达水平乳腺癌的临床数据及治疗效果有限，尤其是化疗获益方面。本研究评估了 ER 低表达（1%-10%）的乳腺癌患者对新辅助化疗（NAC）的病理反应，并与 ER 阳性率>10%和 ER 阴性的乳腺癌患者进行了比较。我们进一步探讨了 ER 表达水平与复发和生存之间的差异。
接受新辅助化疗后行确定性手术的 II 期和 III 期 HER2 阴性原发性乳腺癌患者，根据 ER 百分比分为三组：ER 阴性、ER 低表达阳性（1%-10%）和 ER 阳性率>10%。采用逻辑回归模型评估各变量与病理完全缓解（pCR）之间的相关性。采用 Kaplan-Meier 分析估计生存结果。采用 Cox 模型调整患者和肿瘤特征。
共分析了 241 例患者。所有患者中，22 例（9.1%）为 ER 低表达阳性，159 例（66.0%）为 ER 阳性率>10%，60 例（24.9%）为 ER 阴性。与 ER 阳性率>10%相比，ER 低表达阳性与更高的 pCR 率显著相关（OR，0.249；95%CI，0.067-0.923；P=0.038）。中位随访时间 32 个月后，ER 低表达阳性患者的无病生存（DFS）和总生存（OS）明显差于 ER 阳性率>10%患者，但与 ER 阴性患者相似。调整协变量后，ER 低表达阳性与较差的 DFS 显著相关。
本研究结果表明，与 ER 阳性率>10%的乳腺癌患者相比，ER 低表达阳性乳腺癌对新辅助化疗反应更好，但患者预后更差，与 ER 阴性组相似。这些数据支持该类患者的临床行为与 ER 阴性乳腺癌患者相似，应与 ER 阳性率>10%的患者区别对待。需要进一步的前瞻性研究。
