Abstract P3-07-06: BRCA mutations among Hispanic breast cancer patients of Mexican origin in El Paso, TX

Abstract

Abstract Introduction: El Paso, TX is a large American-Mexican border city of population around 900,000, 85% Hispanic of Mexican origin. Limited cancer research has been conducted in this population. The relative homogeneity of this Hispanic population lends a unique opportunity to study the prevalence of BRCA mutations among Hispanic patients of Mexican origin, to identify reported Mexican founder or recurrent mutations, and to study the breast cancer characteristics in mutation carriers. Methods: Hispanic women with a personal history of breast cancer, who presented consecutively for genetic cancer risk assessment, were enrolled in an Institutional Review Board -approved registry and underwent BRCA testing bases on NCCN guidelines. The characteristics of tumors and patients with positive BRCA mutation were analyzed. Descriptive statistics were utilized. Results: 59 patients were screened; 13 patients (22%) tested positive. Mean age was 50 years; 8 patients (62%) had stages I or II, 2 patients stage III, and 3 unknown. 10 (77%) ductal, 1 (7%) lobular and 2 undetermined; 30% had ER positive tumors versus 61% ER negative; 69% had HER2 -neu negative tumors and 23% HER2-neu positive; 62% were triple negative. Nine patients (69%) were diagnosed with breast cancer at younger than 50 years. Median BMI was 31.78. Ten patients had BRCA1 mutations and 3 BRCA2 mutations. A total of 9 unique deleterious BRCA Mutations were observed, BRCA1 R71G (330A>G);del exons 1-2;C1787S(5478T>A) and G1788D(5482 G>A); C1225X (3794 C>A); A 1708E(5242 C>A); R1751X(5370C>T; and del exons 9-12 and BRCA2 Q742X (2452 C>T); and 3492 insT Conclusion: This study confirms that breast cancer patients with BRCA mutations in the El Paso, TX present at a younger age, and have predominantly triple negative tumors. Of particular interest is 44% (4 of 9) BRCA mutations (BRCA1 exon 9-12 del; C1787S & G1788D and BRCA 2 3492insT; Q742X) identified have been reported as recurrent mutations in Hispanic individuals from Mexico as the country of origin, including BRCA1 ex9-12del, the 1st Mexican founder mutation and 100% of the BRCA2 mutations. A more cost-effective approach to initial screening of Hispanic individuals based on country of origin may be desirable and would potentially decrease the number of cases requiring complete sequencing. Increasing breast cancer awareness and encouraging genetic counseling among high risk younger patients of Mexican descent is also needed. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-07-06.