Abstract P5-09-15: Is BRCA-testing based on risk models still a valid approach in developing countries?

Abstract

Abstract Background: Genetic testing is not affordable in Mexico; average BRCA1&2 testing is $900, while average income in Mexico is $6423 per year. Genetic testing can be an economic burden for public-funded institutions. Current NCCN for genetic counselling and testing are broad to avoid missing patients at risk. Nonetheless, this approach could not be realistic in developing countries, thus we still must select our pts with risk evaluation models. This study describes the features of our BRCA mutation carriers. Methods: New Breast Cancer (BrCa) cases were selected from nov2016 to march2018 according to NCCN criteria for genetic counseling. We gathered demographic, family and medical data. We also calculated the likelihood of carrying a BRCA mutation in each patient with one of two risk models: the Family History Assessment Tool (FHAT) or BRCAPRO. NGS analysis and MLPA for BRCA1&2 were performed in selected pts according to coverage, and availability of the test. The main target of the study was to compare the features of patients carrying a BRCA mutation (mBRCA) vs non-carriers, and the eligibility of the pts according to the risk models. Results: We offered genetic counseling to 180 pts based on personal or familial BrCa history. Median age was 44y (range 21-71). 18 (10%) pts had bilateral cancer, 2 (1.1%) had Br and ovarian Ca. 160 (88.9%) tumors were DCI, 10 (5.6%) pts didn't have cancer. 63 (35%) were TN, 87 (48.3%) were HR positive. All of them met criteria according to NCCN guidelines, but only 87 (48.3%) pts met criteria according to the risk evaluation models. 15 pts refused genetic testing because of lack of coverage. 63 (35.6%) pts had genetic testing, 21/64 (32.8%) of them were carriers of BRCA1 or BRCA2 mutation. TBNC was more frequent seen in BRCA mutated carriers vs non-carriers (p>0.024). Family History (FH) was seen in all but one carrier vs non-carriers (p>0.001), and all carriers met criteria by any risk model p>0.0001. Age was not statistically different between groups (p=0.472), but none carrier was younger than 30y. Conclusions: We confirm that the use of risk evaluation models are useful to identify mBRCA carriers, 32.8% in our cohort. Some features such as TNBC with family history were statistically different between carriers vs non-carriers. 23 pts were positive for risk model but were not mBRCA carriers, which underlines the need to offer larger genetic testing. Also, younger patients (21-30y) had more frequently triple positive phenotypes, and all were negative for BRCA testing; a TP53 testing would also needed. Unfortunately, multi-gene panels are more expensive than BRCA testing. Citation Format: Pacheco-Cuellar G, Valdes-Andrade J, Campos-Gomez KA, Campos-Gomez S. Is BRCA-testing based on risk models still a valid approach in developing countries? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-15.