AB012. SOH21AS238. The natural history and oncological outcomes of HER2 positive breast cancer in the West of Ireland
Clinical Breast Session

AB012. SOH21AS238. The natural history and oncological outcomes of HER2 positive breast cancer in the West of Ireland

Eoin Kerin1, Colm O’Flaherty1, Matthew Davey1, Peter Francis McAnena1, Elizabeth Maher2, Atif Shahzad2, Taqbal Iqbal2, Mattia Lunardi2, Ray McLaughlin1, Karl Sweeney1, Carmel Malone1, Michael Kevin Barry1, Aoife Lowery1, William Wyns2, Osama Soliman2, Michael Kerin1

1The Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland; 2Department of Cardiovascular Medicine, National University of Ireland, Galway, Ireland

Background: Human epidermal growth factors receptor-2 (HER2) positive breast cancer accounts for 10–25% of new diagnoses. The aim of the current study was to outline clinicopathological and immunohistochemical characteristics and determine oncological outcomes in HER2+ breast cancer.

Methods: Consecutive female patients with HER+ BC managed in a single institution between 2005–2015 were included. Clinicopathological features of HER2 BC were determined. Predictors of complete pathological response (pCR) were assessed using binary logistic regression. Disease-free survival (DFS) and overall survival (OS) were determined using Kaplan-Meier (log-rank) analyses.

Results: Five hundred and seven consecutive patients were included with mean age 56.9±13.7 years (23.0–95.0 years). Median follow up was 111.5 months. Seventy-four percent of patients had T1–2 disease (375/507), 46.5% had nodal involvement (236/507), 93.9% had grade 2–3 disease (476/507) and 83.2% had ductal histological subtype (422/507). One hundred and twenty-six patients underwent neoadjuvant therapies, 44.4% of whom achieved pCR (56/126). T1–2 cancers [odds ratio (OR): 8.793, 95% confidence interval (95% CI): 1.088–71.076, P=0.041], estrogen receptor negativity (ER−) (OR: 2.556, 95% CI: 1.239–5.269, P=0.011) and progesterone receptor negativity (PgR−) (OR: 2.450, 95% CI: 1.184–5.068, P=0.016) all predicted pCR. DFS was 74.2% (376/507) and OS was 76.5% (388/507) at median follow up. Age greater than 65 (both P<0.001), increased tumour stage (both P<0.001), increased nodal stage (both P<0.001), ER− (both P<0.001), PgR− (DFS: P=0.005 & OS: P<0.001) and pCR (DFS: P=0.033 & OS: P=0.032) all predicted DFS and OS.

Conclusions: In patients with HER2+ breast cancer, pCR rates can be predicted from routine clinicopathological and immunohistochemical data. Furthermore, survival outcomes may be predicted based on age, disease burden and immunohistochemical tumour properties.

Keywords: Breast cancer; personalised medicine; precision medicine; molecular medicine


Funding: None.


Conflicts of Interest: AL serves as an unpaid editorial board member of Mesentery and Peritoneum. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

doi: 10.21037/map-21-ab012
Cite this abstract as: Kerin E, O’Flaherty C, Davey M, McAnena PF, Maher E, Shahzad A, Iqbal T, Lunardi M, McLaughlin R, Sweeney K, Malone C, Barry MK, Lowery A, Wyns W, Soliman O, Kerin M. SOH21AS238. The natural history and oncological outcomes of HER2 positive breast cancer in the West of Ireland. Mesentery Peritoneum 2021;5:AB012.

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