Neoadjuvant chemotherapy with trastuzumab in HER2-positive breast cancer: pathologic complete response rate, predictive and prognostic factors

Buzatto, I.P.C.; Ribeiro-Silva, A.; Andrade, J.M.; Carrara, H.H.A.; Silveira, W.A.; Tiezzi, D.G.

Abstract

The purpose of this study was to retrospectively review the pathologic complete response (pCR) rate from patients (n=86) with stage II and III HER2-positive breast cancer treated with neoadjuvant chemotherapy at our institution from 2008 to 2013 and to determine possible predictive and prognostic factors. Immunohistochemistry for hormone receptors and Ki-67 was carried out. Clinical and pathological features were analyzed as predictive factors of response to therapy. For survival analysis, we used Kaplan-Meier curves to estimate 5-year survival rates and the log-rank test to compare the curves. The addition of trastuzumab to neoadjuvant chemotherapy significantly improved pCR rate from 4.8 to 46.8%, regardless of the number of preoperative trastuzumab cycles (P=0.0012). Stage II patients achieved a higher response rate compared to stage III (P=0.03). The disease-free and overall survivals were not significantly different between the group of patients that received trastuzumab in the neoadjuvant setting (56.3 and 70% at 5 years, respectively) and the group that initiated it post-operatively (75.8 and 88.7% at 5 years, respectively). Axillary pCR post neoadjuvant chemotherapy with trastuzumab was associated with reduced risk of recurrence (HR=0.34; P=0.03) and death (HR=0.21; P=0.02). In conclusion, we confirmed that trastuzumab improves pCR rates and verified that this improvement occurs even with less than four cycles of the drug. Hormone receptors and Ki-67 expressions were not predictive of response in this subset of patients. Axillary pCR clearly denotes prognosis after neoadjuvant target therapy and should be considered to be a marker of resistance, providing an opportunity to investigate new strategies for HER2-positive treatment.

Citation

Buzatto, I., Ribeiro-Silva, A., Andrade, J., Carrara, H., Silveira, W., & Tiezzi, D. (2017). Neoadjuvant chemotherapy with trastuzumab in HER2-positive breast cancer: pathologic complete response rate, predictive and prognostic factors. #Journal not on list, 50(2), Article e5674. https://doi.org/10.1590/1414-431x20165674

• Journal Article Type: Article
• Acceptance Date: Sep 21, 2016
• Publication Date: Jan 26, 2017
• Deposit Date: Oct 25, 2024
• Publicly Available Date: Oct 25, 2024
• Journal: Brazilian Journal of Medical and Biological Research
• Electronic ISSN: 0100-879X
• Peer Reviewed: Peer Reviewed
• Volume: 50
• Issue: 2
• Article Number: e5674
• DOI: https://doi.org/10.1590/1414-431x20165674