CLINICAL PROFILE OF PATIENTS AT RISK OF HEREDITARY BREAST CANCER IN THE PUBLIC HEALTH SYSTEM OF THE FEDERAL DISTRICT, BRAZIL

Introduction: Identifying patients (pts) with breast cancer (BC) harboring germline pathogenic variants (GPVs) is important due to clinical implications about genetic counseling and cancer surveillance for the patients and its relatives. Even though the cost-effectiveness of genetic testing for the detection of GPVs has already been proven, this technology is not available in the Brazilian public health system (PH). Objective: The present study aims to describe the clinical profile of patients at risk of hereditary BC in a tertiary PH hospital at the Federal District (DF). Methods: Patients with a previous diagnosis of BC, on treatment or follow-up at DF PH service, were evaluated for the risk of hereditary BC from October 2020 to March 2021. Pts who fulfilled criteria for genetic testing, according to NCCN criteria (version 1.2020), were defined as at risk of hereditary BC. All study participants signed an informed consent and received genetic counseling. Results: A total of 100 pts out of 125 met at least one of the NCCN clinical criteria for genetic testing. The median age at BC diagnosis was 41 yo (28 – 78 yrs). The most common histological subtype was invasive ductal carcinoma (93%) and immunohistochemistry was positive for hormonal receptors in 73% with overexpression of HER2 in 24% of the samples. Most pts with high risk were diagnosed at advanced stages: 79% at stages IIB to IIIC and 11% already with metastasis, while only 10% at stages IA to IIA. NCCN criteria more frequently found were age at diagnosis < or = 45 yo (68%), familial history of BC <50 yo or ovarian cancer (33%), >2 relatives with history of BC, ovarian, prostate, or pancreatic cancer (28%) and triple negative tumors in patients <60 yo (22%). Only 14 pts proceeded with out-of-pocket multigene panel testing, 5 (35,7%) had GPVs (2 BRCA2, 2 BRCA1, 1TP53). Conclusion: In our study, most patients at risk of hereditary BC had diagnosis at advanced stages of disease. This usually leads to worst disease outcomes. We hope to raise data about the need of providing genetic testing in Brazil, which could lead to the incorporation of risk reduction strategies (screening and prophylactic measures).