Clinicopathologic Features and Digital Imaging Analysis of HER2 Protein in Breast Carcinomas With Different HER2 Fluorescence in Situ Hybridization Patterns.
Aidan C Li, Scott Hammond, Debra Crosby, Zaibo Li, Anil V Parwani
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引用次数: 0
Abstract
Background: HER2-targeted therapies have significantly improved outcomes for patients with HER2-positive breast cancer (BC), which represents 15% to 20% of all BC cases. HER2 status is assessed via immunohistochemistry (IHC) and/or in situ hybridization (ISH), dividing BCs into five groups (G1-G5).
Patients and methods: In a study of 2,702 primary BC cases, comprising 12.7% G1, 0.2% G2, 2.8% G3, 8.5% G4, and 75.9% G5, we analyzed clinicopathologic features and HER2 protein expression digitally for each ISH group.
Results: Notably, G5 cases had a higher proportion of lobular carcinoma (13.9%) compared to other groups. G3 cases showed the highest percentage of grade 3 tumors (56.9%), while G5 cases had the lowest (21.4%). Additionally, G5 cases had the highest rate of estrogen receptor (ER) positivity (84.6%), while G1-HC (high copy number) cases had the lowest (70.4%). Most G1-HC cases were HER2 IHC 3+ (76.1%), while most G5 cases were IHC 0/1+ (75.7%). IHC 2+ was most common in G1-LC (low copy number) and G3 cases (83.8% and 90.7%, respectively), with G4 cases predominantly IHC 2+ (56.3%) and IHC 1+ (30.1%). Discordant HER2 IHC and ISH results were observed in 12 cases (0.4%), including 7 G1-HC (2.3%), 4 G1-LC (10.8%), and 1 G5 case (0.1%). Digital quantification of HER2 IHC levels in all groups except G5 revealed that G1-HC tumors had the highest HER2 protein expression, followed by G3, with G4 showing the lowest.
Conclusion: These findings offer valuable insights into the clinicopathologic characteristics and future management for different HER2 ISH groups.
期刊介绍:
Clinical Breast Cancer is a peer-reviewed bimonthly journal that publishes original articles describing various aspects of clinical and translational research of breast cancer. Clinical Breast Cancer is devoted to articles on detection, diagnosis, prevention, and treatment of breast cancer. The main emphasis is on recent scientific developments in all areas related to breast cancer. Specific areas of interest include clinical research reports from various therapeutic modalities, cancer genetics, drug sensitivity and resistance, novel imaging, tumor genomics, biomarkers, and chemoprevention strategies.