UNASSIGNED: In this study, histological specimens were obtained from 120 male patients diagnosed and treated for primary invasive breast cancer from 1995 to 2022 at Breast Cancer Units in Bergisch Gladbach, Chemnitz, and Zwickau, Germany. HER2 immunostaining and in situ hybridization were performed by central pathology and evaluated based on the ASCO/CAP guidelines. The correlation of expression of HER2 low with tumor biological characteristics and patient outcomes was investigated.
UNASSIGNED: Out of all cases, four patients (3.3%) showed HER2 positivity (3+), 39 (32.5%) patients were classified as HER2 low, 7 (5.8%) were HER2 2+ (no amplification), 32 (26.7%) were HER2 1+, and 77 (64.2%) were classified as HER2 zero. Out of 77 HER2 zero cases, 47 tumors (61.0%) showed incomplete staining, with <10% of tumor cells classified as HER2 ultralow. No statistical correlation between HER2 low and tumor biological characteristics and patients\' survival was found.
UNASSIGNED: Our findings show a notable, albeit lower, prevalence of HER2 low expression in primary MBC. However, tumors expressing HER2 low do not show specific tumor biological features to define a new breast cancer subtype in MBC. Our results suggest that a significant number of MBC patients could benefit from ADCs, as shown in FBC. Further studies are required to better understand HER2 low breast cancer, both generally and in MBC.
■在这项研究中,组织学标本是从1995年至2022年在BergischGladbach的乳腺癌单位诊断和治疗的120名男性患者中获得的,Chemnitz,和Zwickau,德国。通过中心病理学进行HER2免疫染色和原位杂交,并根据ASCO/CAP指南进行评估。研究HER2低表达与肿瘤生物学特性和患者预后的相关性。
■在所有情况下,4例患者(3.3%)显示HER2阳性(3+),39例(32.5%)患者被归类为低HER2,7例(5.8%)为HER2+(无扩增),32例(26.7%)为HER21+,77(64.2%)被归类为HER2零。在77例HER2中,零病例,47例肿瘤(61.0%)染色不完全,<10%的肿瘤细胞被分类为HER2超低。HER2低与肿瘤生物学特征和患者生存期无统计学相关性。
■我们的研究结果表明,尽管更低,原发性MBC中HER2低表达的患病率。然而,低表达HER2的肿瘤不显示特定的肿瘤生物学特征来定义MBC中的新乳腺癌亚型。我们的结果表明,大量的MBC患者可以从ADC中受益,如FBC所示。需要进一步的研究来更好地了解HER2低乳腺癌,一般和MBC。