Clinicopathological response to neoadjuvant therapies and pathological complete response as a biomarker of survival in human epidermal growth factor receptor-2 enriched breast cancer – A retrospective cohort study. (October 2021)

• Record Type: Journal Article
• Authors: Davey, Matthew G.; Kerin, Eoin; O'Flaherty, C.; Maher, Elizabeth; Richard, Vinitha; McAnena, Peter; McLaughlin, Ray P.; Sweeney, Karl J.; Barry, Michael K.; Malone, Carmel M.; Wyns, William; Soliman, Osama; Miller, Nicola; Keane, Maccon M.; Lowery, Aoife J.; Kerin, Michael J.
• Is Part Of: Breast. Volume 59(2021)
• Page Start: 67
• Page End: 75
• Publication Date: 2021-10
• Subjects: Breast cancer -- HER2 gene -- Pathological complete response -- Personalised medicine -- Precision medicine; Breast -- Diseases -- Periodicals; Breast -- Tumors -- Periodicals; Breast -- Periodicals; Electronic journals; Periodicals; 616
• DOI: 10.1016/j.breast.2021.06.005
• Languages: English
• ISSNs: 0960-9776

Abstract

Abstract: Background: Human epidermal growth factor receptor-2 (HER2) is overexpressed in 20–25% of breast cancers. Complete eradication of disease following neoadjuvant therapies and chemotherapy has been referred to as pathological complete response (pCR). Aims: To determine clinicopathological predictors of pCR to neoadjuvant therapies and to evaluate pCR as a surrogate to enhanced survival. Methods: Consecutive female patients with HER2 positive (HER+) breast cancer managed surgically in a single institution between 2005 and 2015 were included. Descriptive statistics and binary logistic regression were used to determine predictors of pCR. Appraisal of pCR as a predictor of survival was performed using Kaplan-Meier curves and Cox regression analysis. Results: 451 patients were included with a mean age of 56.6 ± 13.4 years (range 23–95). Disease-free (DFS) and overall survival (OS) was 82.3% (371/451) and 82.6% (376/451) respectively with a median follow-up of 108.0 months (range 3–184.0). 118 were treated in the neoadjuvant setting (26.2%): tumour size <50 mm (Odds Ratio (OR): 12.156, P = 0.023) and progesterone receptor negativity (OR: 2.762, P = 0.008) independently predicted breast pCR, while ductal carcinoma (OR: 3.203, P = 0.030) and grade 3 disease (OR: 2.788, P = 0.018) predicted axillary pCR. Both breast and axillary pCR predicted enhanced DFS (Hazard Ratio (HR): 0.470 & HR: 0.449) and OS (HR: 0.383 & HR: 0.307). Axillary pCR independently predicted improved OS (HR: 0.326). Conclusion: pCR is sensitive biomarker and surrogate to survival outcomes in HER2+ breast cancer. Patients likely to achieve pCR may be predicted from traditional clinicopathological characteristics and molecular parameters. Highlights: Clinicopathological data predict patients who achieve pCR in HER2+ breast cancer. pCR is a sensitive biomarker of survival in HER2 positive breast cancer. Patients achieving pCR have reduced risk of breast cancer recurrence and mortality. pCR can aid patient prognostication in the era of personalised medicine.