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

Breast Cancer Res Treat. 2023 Jun;199(2):363-370. doi: 10.1007/s10549-023-06909-z. Epub 2023 Mar 29.

Abstract

Purpose: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Access disparities; BRCA; Breast cancer; Germinal gene testing; Latin American.

MeSH terms

  • BRCA1 Protein / genetics
  • BRCA2 Protein / genetics
  • Breast Neoplasms* / diagnosis
  • Breast Neoplasms* / epidemiology
  • Breast Neoplasms* / genetics
  • Chile / epidemiology
  • Female
  • Genetic Predisposition to Disease
  • Genetic Testing
  • Germ-Line Mutation
  • Humans
  • Middle Aged
  • Retrospective Studies

Substances

  • BRCA1 protein, human
  • BRCA1 Protein
  • BRCA2 protein, human
  • BRCA2 Protein