Background: Breast cancer is the most prevalent women’s cancer, representing about a third of all cancers diagnosed in women. Estrogen receptor (ER) is an important transcription factor expressed in 70% to 75% of all breast cancers. Of these breast cancers, the majority express ER robustly in 91–100% of tumor cells. However, a minority of breast cancers express ER in intermediate levels between 11% and 90% of tumor cells. The characteristics and outcomes of this intermediate subset of ER-positive breast cancers are not well studied. Methods: We retrospectively reviewed the medical records of all breast cancer patients treated in our Cancer Center over a period of 8 years. Patients were grouped according to the level of ER expression in tumors with negative/low ER expression, intermediate ER expression, and high ER expression, and the groups were compared for tumor characteristics and outcomes. Results: Patients with high ER levels (91% to 100%) represented 75.6% (600 of 794 patients), patients with intermediate ER expression represented 11.5% of the entire group (91 of 794 patients), and patients with negative/low ER expression (ER expression 0–10%) represented 12.9% of the entire cohort (103 of 794 patients). Patients with intermediate ER expression presented at a younger age than patients with high-ER cancers, as well as a more advanced stage and higher grade. These characteristics were more akin to patients with negative/low ER levels. Mastectomy was the surgical method of resection more commonly in ER-intermediate tumors than in ER-high tumors. The relapse-free survival (RFS) of patients with ER-intermediate cancers was worse than the RFS of patients that expressed ER robustly. Conclusion: The level of expression of ER defines groups of patients with varying characteristics and prognoses. Patients in the intermediate ER expression group had notable differences from patients in the high ER expression group including younger age, (more often) a higher grade, and low PR positivity. Differences observed between the group of patients with intermediate ER expression and that with high ER expression may help to prioritize therapeutic algorithms.
背景：乳腺癌是最常见的女性恶性肿瘤，约占女性所有确诊癌症的三分之一。雌激素受体（ER）作为一种重要的转录因子，在70%至75%的乳腺癌中表达。在这些乳腺癌中，绝大多数肿瘤细胞（91%-100%）呈现ER高表达。然而，少数乳腺癌的ER表达水平处于中等范围（肿瘤细胞表达率为11%-90%）。目前对这类中等ER表达水平乳腺癌的临床特征及预后研究尚不充分。 方法：我们回顾性分析了本癌症中心8年间收治的所有乳腺癌患者的病历资料。根据肿瘤组织中ER表达水平将患者分为阴性/低表达组、中等表达组和高表达组，比较各组患者的肿瘤特征及临床结局。 结果：在794例患者中，ER高表达组（91%-100%）占75.6%（600例），ER中等表达组占11.5%（91例），ER阴性/低表达组（0%-10%）占12.9%（103例）。与ER高表达组相比，ER中等表达组患者发病年龄更轻，临床分期更晚，组织学分级更高。这些特征更接近于ER阴性/低表达组患者。在手术方式上，ER中等表达组比ER高表达组更常采用乳房切除术。ER中等表达组患者的无复发生存期显著差于ER高表达组。 结论：ER表达水平可界定具有不同临床特征和预后的患者群体。ER中等表达组患者与高表达组相比存在显著差异，包括发病年龄更轻、组织学分级更高、孕激素受体阳性率更低。两组间观察到的差异可能为临床治疗策略的优化选择提供依据。
肿瘤(癌症)患者之家