Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E57
Höfundar / Authors: Linda Vidarsdottir1,4, Snædís Ragnardóttir1, Elinborg J. Olafsdottir2, Rosa B. Barkardottir3,4, Olöf Bjarnadottir5, Jon Gunnlaugur Jonasson1,3, Stefan Sigurdsson1,4, Laufey Tryggvadottir1,2,4
Starfsvettvangur / Affiliations: 1Faculty of Medicine, University of Iceland, Sturlugata 8, Reykjavik, Iceland 2Research and Registration Center, Icelandic Cancer Society, Reykjavik, Iceland 3Department of Pathology, Landspitali – University Hospital, Reykjavik, Iceland 4BioMedical Center, University of Iceland, Sturlugata 8, Reykjavik, Iceland 5Department of Oncology, Landspitali – University Hospital, Reykjavik Iceland
Kynnir / Presenter: Linda Viðarsdóttir
Estrogen receptor (ER)-positive breast cancer is typically associated with better prognosis than ER-negative disease; however, this trend appears to differ in BRCA2 mutation carriers and younger patients. We tested 85% of all 2817 eligible women diagnosed with breast cancer in Iceland during 1980-2004 for the 999del5 BRCA2 pathogenic variant. We assessed breast cancer-specific survival and clinical characteristics based on ER-status across three distinct ER-positive groups. For ER-positive breast cancer, 15-year survival rates were 49.7%, 55.2%, and 74.7% for BRCA2 carriers, 40 years or younger non-carriers, and older non-carriers, respectively. In contrast, for ER-negative breast cancer, 15-year survival was comparable across all three groups, ranging from 64.0% to 69.3%. Next, we used the TCGA database to compare differentially expressed genes between young breast cancer patients and older patients with ER-positive tumors. We found numerous genes involved in cell proliferation, angiogenesis and metastasis to be dysregulated. Taken together, BRCA2 mutation carriers and young breast cancer patients with ER-positive tumors have an inferior prognosis, even worse than triple-negative breast cancer patients. These patients need special attention, and identification of new drug targets is vital to improve survival in these subgroups of breast cancer.