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Bai Q, Lv H, Bao L, Yang Y, Zhang X, Chang H, Xue T, Ren M, Zhu X, Zhou X, Yang W. Invasive Breast Cancer with HER2 ≥4.0 and <6.0: Risk Classification and Molecular Typing by a 21-Gene Expression Assay and MammaPrint Plus BluePrint Testing. BREAST CANCER (DOVE MEDICAL PRESS) 2023; 15:563-575. [PMID: 37554155 PMCID: PMC10406110 DOI: 10.2147/bctt.s420738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/26/2023] [Indexed: 08/10/2023]
Abstract
PURPOSE To investigate the HER2 status and clinicopathological features in invasive breast cancer with HER2 ≥4.0 and <6.0, which has always been controversial. METHODS Forty breast cancer cases with HER2 ≥4.0 and <6.0 by fluorescence in situ hybridization (FISH) were collected and classified into two groups based on the HRE2/CEP17 ratio (Group A: ≥2.0, n=22; Group B: <2.0, n=18). Clinicopathological characteristics, HER2 status, risk classification, and molecular typing were further analyzed and compared by 21-Gene expression assay and MammaPrint plus BluePrint test. RESULTS The majority of cases in both groups were invasive carcinoma (NOS), with histological grade II, HR+, Ki-67 ≥20%, HER2 2+, and a high risk of recurrence, although younger patients and lymph node metastases were more common in Group A. Surprisingly, all HR+ breast cancers in both groups were classified as luminal-type, HR- cases were all basal-type or unknown, and the index of HER2 in all cases was <0.000 using the BluePrint test, which indicated that HER2 status should be negative. Furthermore, the level of HER2 mRNA expression in all cases of both groups was <10.7, which was defined as HER2 negative by the 21-Gene expression assay. In addition, 10 patients of Group A received anti-HER2 neoadjuvant therapy; only one patient with HR- achieved Grade 5 based on the Miller-Payne system, whereas none of the patients achieved pathological complete response (pCR) based on the Residual Cancer Burden system. CONCLUSION Group A breast cancer, which has always been unquestionably diagnosed as HER2 amplification, was more likely to be HER2 negative and derived less benefit from anti-HER2 neoadjuvant chemotherapy. Group A breast cancer should be distinguished from classical HER2-positive breast cancers when assessing HER2 FISH, and a larger cohort of Group A patients should be included in further studies.
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Affiliation(s)
- Qianming Bai
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Hong Lv
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Longlong Bao
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Yu Yang
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Xin Zhang
- Department of Pathology, Fudan University Zhongshan Hospital, Shanghai, 200032, People’s Republic of China
| | - Heng Chang
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Tian Xue
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Min Ren
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Xiaoli Zhu
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Xiaoyan Zhou
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
| | - Wentao Yang
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, People’s Republic of China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, People’s Republic of China
- Institute of Pathology, Fudan University, Shanghai, 200032, People’s Republic of China
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