Abstract A27: The genomic profile of BRCA1-associated estrogen-receptor positive breast cancer does not resemble BRCA1-associated triple negative cancers, but is more similar to BRCA2-associated breast cancer

Conclusion: The majority of BRCA1-associated ER+ tumors did not show a BRCA1-like genomic profile, even though LOH analysis indicated that loss of the wildtype BRCA1 allele was a frequent event. Therefore, it is likely that the complete loss of the BRCA1 gene plays a crucial role in tumorgenesis in this group of breast tumors. Remarkably, a BRCA2-like genomic profile was observed in the majority of ER+ BRCA1 associated tumors in this series. A clinical consequence of our findings is that ER+ BRCA1-associated breast tumors are probably highly sensitive to PARP inhibitors, similar to TN BRCA1-associated breast cancers. However, as ER+ BRCA1-mutated tumors clearly have different tumor characteristics compared to TN BRCA1-mutated tumors, they should be considered as a special group, and response to therapies exploiting the BRCA1 gene defect should be specifically monitored in this subgroup.Citation Format: Esther H. Lips, Rashmie Debipersad, Esther Scheerman, Lennart Mulder, Lizet E. van der Kolk, Jelle Wesseling, Frans B.L. Hogervorst, Petra M. Nederlof. The genomic profile of BRCA1-associated estrogen-receptor positive breast cancer does not resemble BRCA1-associated triple negative cancers, but is more similar to BRCA2-associated breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A27.
Source: Molecular Cancer Research - Category: Cancer & Oncology Authors: Tags: Genomics - Sporadic and Hereditary: Poster Presentations - Proffered Abstracts Source Type: research