Criteria for the identification of hereditary breast cancer syndromes. Review of the literature and recommendations for the Instituto Nacional de Cancerologia Colombia

Introduction: Hereditary breast and ovarian cancer syndromes (HBOC) represents 5% to 10% of all breast cancer cases, and BRCA1 and BRCA2 explain most of these syndromes. Multiple guidelines and updated recommendations have been published to define which patients should be selected for genetic testing based on a clinical suspicion of a HBOC syndrome. For context, the Instituto Nacional de Cancerologia from Colombia developed an "Institutional Program for the identification and management of families with suspected hereditary cancer" for healthcare purposes, within which breast cancer is the most referred pathology to the genetics service (55%; 540/986). Inherited cancer was diagnosed in 21% of the patients with breast cancer who met NCCN criteria; most of these were associated with BRCA1 and BRCA2 mutations (12.3%) and to a lesser extent to other breast cancer susceptibility genes (8.6%). Objective: To identify the most implemented selection criteria to diagnose inherited breast cancer cases, through a review of the literature, and to achieve an institutional consensus on the indications for referral to genetic counseling and genetic testing for diagnostic and systemic treatment with PARPi. Materials and methods: A narrative review of the scientific literature published in the last 10 years as of August 30, 2021 on the prevalence of germline mutations in the BRCA1 and BRCA2 genes, and in other non-BRCA genes, in patients with breast cancer was carried out. Overall, 146 articles were first identified but only 41 were selected. Within the functional units of breast and soft tissue, genetics and clinical oncology, the available evidence was presented and a broad discussion was carried out; finally the indications for referral to genetic counseling, for genetic testing and for systemic treatment with PARPi were defined. Results: As reported in the literature, clinical criteria for HBOC syndrome should include: triple negative subtype, bilateral presentation, very early age of diagnosis and family history (FH) of breast cancer before 50 years of age or ovarian cancer at any age. Conclusions: The NCCN recommendations for referral to genetic counseling and ordering genetic testing to diagnose HBOC cases are adopted at the Instituto Nacional de Cancerologia from Colombia, as well as the OlympiA study criteria for ordering genetic testing to guide systemic PARPi therapy. This will allow our Institution to adequately offer this service to the Colombian population.