Abstract P2-09-11: Prevalence of patients with indication of genetic evaluation for hereditary breast and ovarian syndrome in the Brazilian cohort study - AMAZONA III

Abstract

INTRODUCTION: The evaluation of an individual with risk of hereditary breast cancer is based on the patient's family history and the characteristics of the neoplasia. BRCA1 and BRCA 2 are the most common genes associated with hereditary predisposition for breast or ovarian cancer. The evaluation of an individual with risk of hereditary breast cancer is key to identify patients with indication to BRCA test. Recent studies in US suggests that 31 to 34% of patients with breast cancer should be referred for genetic evaluation. In Brazil, the proportion of BC patients with indication to genetic evaluation is unknown. OBJECTIVE: To describe the prevalence of breast cancer patients enrolled in the AMAZONA III study with indication for genetic evaluation considering the criteria for hereditary breast and ovarian cancer syndrome (HBOC). METHOD: We evaluated the database of the AMAZONA III observational, prospective cohort study which included 2950 patients newly diagnosed with BC in the period of 2016-18 within 23 Brazilian sites. The criteria used to select patients who should be referred for genetic testing were extracted from the National Comprehensive Cancer Network (NCCN) guideline 2018. The characteristics of interest were summarized through descriptive statistics. RESULTS: A total of 1094 (37%) BC patients had at least one criteria for HBOC syndrome test. The most common criteria for testing was age equal or inferior 45 years (27%), BC diagnosis under 50 years and family history of breast cancer (13.5%). From the 2950 enrolled patients, 651 (22%) had the information about whether an evaluation of BRCA test was performed. Of them only 45 (6.9%) performed BRCA test, one patient from public health system and the others from private health system and from those tested 18 (40%) had an identified pathogenic mutation. CONCLUSION: A high proportion of patients diagnosed with BC in Brazil have a criteria for HBOC syndrome testing. Nonetheless a few patients have access to genetic counseling and BRCA test, especially in the public health system. Therefore its critical to implement health policies to facilitate the access to specialized care in hereditary cancer. Frequency of each criteria regarding all 2950 patientsTotal - n (%)Missing - n (%)<=45 years806 (27.32)62 (2.10)<= 60 years and molecular subtype triple negative234 (7.93)681 (23.08)Family history of ovarian cancer101 (3.42)214 (7.25)<= 50 years and family history of breast cancer388 (13.15)214 (7.25)<= 50 years and personal history of breast cancer26 (0.88)142 (4.81)Personal history of ovarian cancer4 (0.14)142 (4.81) Citation Format: Alessandra BorbaAnton de Souza, Daniela Rosa, Antonio LuiZ Frasson, Felipe Pereira Zerwes, Nathalia Cunha Rossato, Patricia Asthon-Prolla, Sergio Simon, Jose Bines, Carlos Barrios, Alessandra Morelle, Carlos AlbertoSampaio Filho, Max Mano, Rafaela Gomes, Gustavo Werutsky. Prevalence of patients with indication of genetic evaluation for hereditary breast and ovarian syndrome in the Brazilian cohort study - AMAZONA III [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-09-11.

Real-world data on triple-negative breast cancer in Latin America and the Caribbean

“…In Brazil, in a subanalysis of the AMAZONA observational study including 2,950 patients, 1,094 (37%) had at least one criterion for hereditary breast and ovarian cancer syndrome. Of all patients, only 45 (6.9%) underwent BRCA testing, and of those tested, 18 (40%) had an identified pathogenic mutation [45]. Among Latin American cancer patients, the frequency of pathogenic variants in the BRCA gene has been reported to be between 1.2% and 15.6% [46][47][48][49] and between 15% and 28% of breast and ovarian cancer patients unselected for family history of BC in Mexico [50].…”