Access disparities and underutilization of germline genetic testing in Chilean breast cancer patients

• DOI: 10.1007/s10549-023-06909-z
• Publication Date: 2023-03-29T06:02:57Z
• Authors: Francisco Acevedo; Benjamín Walbaum; Mauricio Camus; Manuel Manzor; Sabrina Muñiz; Lidia Medina; Militza Petric; Paula Reyes; Francisco Domínguez; Klaus Puschel; Tomas Merino; M. Loreto Bravo; Mauricio P. Pinto; Carolina Ibáñez; Kevin Hughes; César Sánchez
• Keywords: BRCA2 Protein; BRCA1 Protein; Germinal gene testing; BRCA; 610; Breast Neoplasms; 613; Middle Aged; 03 Good health and well-being; 3. Good health; Breast cancer; 03 Salud y bienestar; Humans; Latin American; Female; Genetic Predisposition to Disease; Genetic Testing; Chile; Medicina y salud; Access disparities; Germ-Line Mutation; Retrospective Studies

Latin American reports on genetic cancer risk assessments are scarce. In Chile, current breast cancer (BC) guidelines do not define strategies for germline genetic testing. Our study sought to quantify the disparities in access to genetic testing in Chilean BC patients, according to international standards and their clinical characteristics to explore improvement strategies.Retrospective analysis of invasive BC databases including patients treated in a Public Hospital (PH) and in an Academic Private Center (AC) in Santiago, Chile between 2012 and 2021.Of 5438 BC patients, 3955 had enough data for National Comprehensive Cancer Network (NCCN) categorization. From these, 1911 (48.3%) fulfilled NCCN criteria for germline testing, of whom, 300 were tested for germline mutations and 268 with multigene panels. A total of 65 pathogenic variants were found in this subset. As expected, BRCA1/2 mutations were the most frequent (17.7%). Access to genetic testing was higher in AC versus PH (19.6% vs. 10.3%, p = 0.0001). Other variables associated with germline genetic testing were BC diagnosis after 2018, being 45 years old or younger at diagnosis, BC family history (FH), FH of ovarian cancer, non-metastatic disease, and triple-negative subtype.In our cohort, 15% of BC patients who met NCCN criteria for germline testing were effectively tested. This percentage was even lower at the PH. Current recommendations encourage universal genetic testing for BC patients; however, our findings suggest that Chile is far from reaching such a goal and national guidelines in this regard are urgently needed. To our knowledge, this is the first study of its kind in Chile and Latin America.