J Cancer 2021; 12(17):5365-5374. doi:10.7150/jca.62830

Research Paper

Discrepancy of Breast and Axillary Pathologic Complete Response and Outcomes in Different Subtypes of Node-positive Breast Cancer after Neoadjuvant Chemotherapy

Shin-Cheh Chen1*✉, Chi-Chang Yu1*, Hsien-Kun Chang2, Yung-Chang Lin2, Yung-Feng Lo1, Shih-Che Shen1, Wen-Lin Kuo1, Hsiu-Pei Tsai1, Hsu-Huan Chou1, Chia-Hui Chu1, Wen-Chi Shen2, Ren-Chin Wu3, Shir-Hwa Ueng3, Yi-Ting Huang4

1. Department of General Surgery, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
2. Department of Hematology-Oncology, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
3. Department of Pathology, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
4. Department of Radiation Oncology, Chang Gung Memorial Hospital at Linkou, Chang Gung University Medical College, Taoyuan, Taiwan
*Shin-Cheh Chen and Chi-Chang Yu contribute equally to this work

This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). See http://ivyspring.com/terms for full terms and conditions.
Citation:
Chen SC, Yu CC, Chang HK, Lin YC, Lo YF, Shen SC, Kuo WL, Tsai HP, Chou HH, Chu CH, Shen WC, Wu RC, Ueng SH, Huang YT. Discrepancy of Breast and Axillary Pathologic Complete Response and Outcomes in Different Subtypes of Node-positive Breast Cancer after Neoadjuvant Chemotherapy. J Cancer 2021; 12(17):5365-5374. doi:10.7150/jca.62830. Available from https://www.jcancer.org/v12p5365.htm

File import instruction

Abstract

Few studies have analyzed the discrepancy between breast pathologic complete response (B-pCR) and axillary node pCR (N-pCR) rates and their impact on survival outcomes in different intrinsic subtypes of early breast cancer after neoadjuvant chemotherapy (NAC). We retrospectively reviewed B-pCR, N-pCR, and total (breast and axillary node) pCR (T-pCR) after NAC to assess the discrepancy and outcomes between 2005 and 2017. A total of 968 patients diagnosed with cT1-4c, N1-2, and M0 breast cancer were enrolled in the study. The median age was 49 years and the median follow-up time was 45 months. Of these patients, 213 achieved T-pCR, 31 achieved B-pCR with axillary node pathologic non-complete response (N-non pCR), 245 achieved N-pCR with breast pathologic non-complete response (B-non pCR), and 479 achieved total (breast and axillary node) pathologic non-complete response (T-non pCR) after NAC. The highest B-pCR and N-pCR rates were found in the hormone receptor-negative, human epidermal growth factor receptor 2-positive HR(-)HER2(+) subtype, while the lowest B-pCR rate was found in the HR(+)HER2(-) subtype. The N-pCR rate was correlated to the B-pCR rate (P<0.001), but was higher than the B-pCR rate in all subtypes. The 5-year overall survival (OS) rates for patients with T-pCR, B-pCR, and N-pCR were 91.2%, 91.7%, and 91.9%, respectively. For non-pCR, non-pCR, and non-pCR, the 5-year OS rates were 73.6%, 78.9%, and 74.7%, respectively (P<0.0001). B-non pCR patients had a lower risk of recurrence than T-non pCR or N-non-pCR patients, although there were no differences in OS among them. In conclusion, the N-pCR rate was higher than the B-pCR rate after NAC in all intrinsic subtypes, and N-non pCR or T-non pCR patients had the worst outcomes.

Keywords: breast cancer, neoadjuvant chemotherapy, pathologic complete response, intrinsic subtype