Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz

Gewählte Publikation:

Steiner, D.
Outcome of breast cancer patients with immunohistochemistry HER2 score 2 and 3 at the Division of Oncology, Graz HER2 diagnostical and clinical refinement.
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2020. pp. 62 [OPEN ACCESS]


Autor*innen der Med Uni Graz:
Balic Marija
Suppan Christoph

Background: Breast cancer is the most common malignancy in women and one of the leading causes of cancer death worldwide. HER2 expressing breast cancer can be targeted with several different established therapeutic options, therefore definition and assessment of HER2 positivity is of clinical relevance. Materials and Methods: We conducted a single-center, retrospective data analysis at the Division of Oncology in Graz. Patients were eligible having invasive breast cancer with a HER2 IHC score of 2+ or 3+ and being diagnosed or treated for breast cancer at our institution between 2006 and 2016. Our aim was to assess the patient composition regarding molecular subtypes and treatment setting. Co-primary end point was clinical outcome in different subgroups. Secondary end point was to assess the number of patients affected by the change in ASCO/CAP guidelines regarding HER2 positivity and whether this element influenced therapeutic decisions and outcomes. Results: Of 611 patients included, 353 had a score of 2+ and 258 of 3+, resulting in 343 HER2 positive, 264 HER2 negative, i.e. 230 luminal-like and 34 triple-negative subtypes, and 4 unknown cases. Of HER2 positive patients, 168 were in adjuvant, 142 in neoadjuvant, and 33 in palliative setting, whereas 155, 77, and 32 HER2 negative patients were in these settings, respectively. OS at 10 years in (neo)adjuvant setting was more than 75%, OS at 5 years in palliative setting was less than 25%. OS at 10 years for HER2 positive patients in (neo)adjuvant setting was significantly better when patients received HER2 targeted therapy (81.38% and 63.48%; p<0.005). Of 353 patients with a score of 2+, 12 patients had a HER2/CEP17 ratio between 2.0 and 2.2 and were therefore affected by the guideline change. Due to the low case number, the influence on therapeutic decisions and outcomes could not be determined. Conclusion: Breast cancer patients with a HER2 IHC score of 2+ and 3+ are a diverse population in different settings. In our study, HER2 targeted therapy was a crucial component in treating HER2 positive patients, leading to significant changes in outcomes. The clinical importance of the change of the ASCO/CAP guidelines could not be determined.

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