Abstract 1721P
Background
In recent years, a greater number of germinal mutations that predispose to the development of tumors have been found. Understanding the interactions between mutations and breast cancer’s subtype is essential for opening new therapeutic and preventive strategies. It is well known what type of breast cancer develops in a hereditary syndrome context; however, the prevalence of HER2 positive tumors with some deleted mutation in genes predisposing to breast cancer, is still not entirely clear.
Methods
This study aims to know the prevalence of HER2-positive tumors, either with positive or negative estrogen and/or progesterone receptors, associated with some germline mutation in a hereditary syndrome context. It is a descriptive and longitudinal study, with retrospective collection of data from patients diagnosed of HER2-positive breast cancer and positive or negative hormone receptors in the intercenter Clinical Management Unit of Medical Oncology.
Results
A total of 1,070 patients diagnosed with HER2-positive breast carcinoma were obtained. Of it, 189 (17.66%) patients underwent a genetic study, finding a germline mutation in 33 patients (3.08% of the global population and 17.46% of the population studied). The most frequent genes were BRCA 1 and 2, MUTYH and ATM.
Conclusions
Breast cancer with overexpression of the HER2 protein and a germline mutation is rare, with an unknown true prevalence. It is associated with mutations in prevalent genes such as BRCA 1 and 2, but also with less frequent ones such as TP53. Prospectives studies are needed to elucidates which patients with HER2 positive breast cancer are better candidates for a germinal test.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.