Valdís Gunnarsdóttir, Magnea Guðríður Frandsen, Soffía R. Gunnarsdottir, Marey Sif Björgvinsdóttir, Stefán Þórarinn Sigurðsson, Jón Gunnlaugur Jónasson and Sigríður Klara Böðvarsdóttir
Introduction: Breast cancer remains the most prevalent cancer among women globally and a leading cause
of cancer-related deaths, with the heterogeneity of BC presenting challenges in treatment efficacy and
patient outcomes. Routine clinical immunohistochemical (IHC) analysis of the estrogen receptor (ER),
progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), along with
clinicopathological variables, currently serve as the key determinants in decision making for adjuvant
treatments. This study aims to analyse IHC expression of three proteins (Aurora-A, BRCA1 and PLK1) and
tumour-stroma ratio (TSR) in relation to breast cancer specific survival.
Methods: A well-defined Icelandic tissue microarray (TMA) cohort of approximately 1,000 breast tumours
were IHC stained for Aurora-A, BRCA1, and PLK1 and analysed for histological TSR. Association between
categorical variables was examined using either Fisher’s exact test or Chi-square test. Other statistical
methods used include Kaplan-Meier survival curves and Cox hazards regression for relative risk and
prognostic significance of different breast cancer subgroups including the breast cancer subtypes,
clinicohistological variables and BRCA2 mutation carriers.
Results: This study is still ongoing but first results from high histological stroma-ratio in breast tumours
indicate worse prognosis among patients with non-luminal breast cancer and high Nottingham grade.
