Conversion of ER and HER2 Status After Neoadjuvant Therapy in Chinese Breast Cancer Patients

Jiaqi Bo; Baohua Yu; Rui Bi; Xiaoli Xu; Yufan Cheng; Xiaoyu Tu; Qianming Bai; Wentao Yang; Ruohong Shui

doi:10.1016/j.clbc.2023.03.002

Conversion of ER and HER2 Status After Neoadjuvant Therapy in Chinese Breast Cancer Patients

Clin Breast Cancer. 2023 Jun;23(4):436-446. doi: 10.1016/j.clbc.2023.03.002. Epub 2023 Mar 8.

Authors

Jiaqi Bo¹, Baohua Yu², Rui Bi², Xiaoli Xu², Yufan Cheng², Xiaoyu Tu², Qianming Bai², Wentao Yang², Ruohong Shui³

Affiliations

¹ Department of Pathology, Fudan University Shanghai Cancer Center, China; Department of Pathology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China.
² Department of Pathology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, China; Institute of Pathology, Fudan University, Shanghai, China.
³ Department of Pathology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, China; Institute of Pathology, Fudan University, Shanghai, China. Electronic address: shuiruohong2014@163.com.

PMID: 36990841
DOI: 10.1016/j.clbc.2023.03.002

Abstract

Background: Few studies have focused on converting ER-low-positive and HER2-low status following neoadjuvant therapy (NAT). We aimed to assess the evolution in ER and HER2 status after NAT in breast cancer patients.

Patients and methods: Our study included 481 patients with residual invasive breast cancer after NAT. ER and HER2 status were assessed in the primary tumor and residual disease, and associations between ER and HER2 conversion and clinicopathological factors were explored.

Results: In primary tumors, 305 (63.4%) cases were ER-positive (including 36 cases of ER-low-positive), 176 (36.6%) were ER-negative. In residual disease, ER status changed in 76 (15.8%) cases, of which 69 cases switched from positive to negative. ER-low-positive tumors (31/36) were the most likely to change. In primary tumors, 140 (29.1%) tumors were HER2-positive, and 341 (70.9%) were HER2-negative (including 209 cases of HER2-low and 132 cases of HER2-zero). In residual disease, 25 (5.2%) cases had HER2 conversion between positive and negative. Considering HER2-low status, 113 (23.5%) cases had HER2 conversion, mostly driven by cases switching either to or from HER2-low. ER conversion had a positive correlation with pretreatment ER status (r = 0.25; P = .00). There was a positive correlation between HER2 conversion and HER2-targeted therapy (r = 0.18; P = .00).

Conclusion: Conversion of ER and HER2 status was observed in some breast cancer patients after NAT. Both ER-low-positive and HER2-low tumors showed high instability from the primary tumor to residual disease. ER and HER2 status should be retested in residual disease for further treatment decisions, especially in ER-low-positive and HER2-low breast cancer.

Keywords: Clinicopathological factor; ER-low-positive; HER2-low; Retrospective study.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Breast Neoplasms* / drug therapy
Breast Neoplasms* / pathology
East Asian People
Female
Humans
Neoadjuvant Therapy
Receptor, ErbB-2

Substances

Receptor, ErbB-2