HER2 intratumoral heterogeneity is independently associated with distal metastasis and overall survival in HER2-positive breast carcinomas.
Breast Cancer Res Treat 2020;
181:519-527. [PMID:
32335801 DOI:
10.1007/s10549-020-05650-1]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 04/17/2020] [Indexed: 01/02/2023]
Abstract
PURPOSE
Human epidermal growth factor receptor 2 (HER2) intratumoral heterogeneity (ITH) occurs in a subset of breast cancers. Our recent study revealed it as an independent predictive factor for the response to anti-HER2 neoadjuvant therapy. In this study, we aimed to investigate its association with distal metastasis.
METHODS
HER2 ITH was assessed using HER2 gene protein assay (GPA) on whole tissue sections of pretreatment biopsies from a cohort of 158 HER2-positive invasive breast carcinomas and correlated with patients' clinical follow-up outcomes along with other clinicopathologic characteristics.
RESULTS
Fifty-seven cases (36%) showed HER2 ITH including 19 with genetic, 8 with both genetic and non-genetic, and 30 with non-genetic ITH. Multivariate analysis demonstrated larger tumor size, positive resected lymph node(s), negative PR, and the presence of HER2 ITH were independently associated with distal metastasis. Additionally, multivariate analysis demonstrated larger tumor size and the presence of HER2 ITH were the only independent factors associated with decreased overall survival (death).
CONCLUSION
The presence of HER2 ITH is an independent factor associated with poor overall survival and increased distal metastasis in HER2-positive breast cancer patients.
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