Association of HER-2/CEP17 Ratio and HER-2 Copy Number With pCR Rate in HER-2-Positive Breast Cancer After Dual-Target Neoadjuvant Therapy With Trastuzumab and Pertuzumab

Fanfan Li; Qian Ju; Cong Gao; Jingjing Li; Xiaolei Wang; Min Yan; Liying Zhang; Meiling Huang; Qihe Long; Xiangting Jin; Nanlin Li

doi:10.3389/fonc.2022.819818

Association of HER-2/CEP17 Ratio and HER-2 Copy Number With pCR Rate in HER-2-Positive Breast Cancer After Dual-Target Neoadjuvant Therapy With Trastuzumab and Pertuzumab

Front Oncol. 2022 Mar 4:12:819818. doi: 10.3389/fonc.2022.819818. eCollection 2022.

Authors

Fanfan Li¹, Qian Ju¹, Cong Gao¹, Jingjing Li¹, Xiaolei Wang¹, Min Yan¹, Liying Zhang², Meiling Huang³, Qihe Long¹, Xiangting Jin¹, Nanlin Li³

Affiliations

¹ Department of Oncology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China.
² Department of Pathology, Xijing Hospital of Air Force Military Medical University, Xi 'an, China.
³ Department of Breast Surgery, Xijing Hospital of Air Force Military Medical University, Xi 'an, China.

Abstract

Objective: To explore the correlation between HER-2 status and pathological complete response (pCR) in HER-2-positive breast cancer after dual anti-HER-2 neoadjuvant therapy with trastuzumab and pertuzumab.

Methods: A total of 57 HER-2-positive breast cancer patients admitted to the Second Affiliated Hospital of Anhui Medical University and Xijing Hospital Affiliated to Air Force Military Medical University, between January 1, 2019 and September 30, 2020, were enrolled in this multicenter retrospective study. HER-2 status, including HER-2/CEP17 ratio and HER-2/cell number ratio, was detected by FISH. The correlation between HER-2 status/clinicopathological data and pCR was analyzed. The ROC curve was drawn to determine the cutoff value.

Results: IHC assessment revealed 40 (70.18%) patients with IHC 3+ and 17 (29.82%) with IHC 2+. 41/57 (71.93%) patients achieved pCR. FISH revealed that the ratio of HER-2/chromosome 17 centromere (HER-2/CEP17) (p<0.001) and the ratio of HER-2/cell number (p<0.001) was significantly correlated with the pCR rate. ROC analysis showed that patients with an HER-2/CEP17 ratio ≥4.495 or HER-2/cell number ≥11.650 have a high pCR rate after dual anti-HER-2 neoadjuvant therapy, suggesting its predictive significance.

Conclusion: The response to dual-targeted neoadjuvant therapy with trastuzumab and pertuzumab was adequate in hormone receptor-negative, HER-2-positive breast cancer patients. HER-2/CEP17 ratio and HER-2/cell number ratio were crucial for predicting efficacy.

Keywords: FISH; HER-2 positive; IHC; breast cancer; dual-target neoadjuvant therapy.