Evaluation of the BRCAPRO model in a cohort of Hispanic families.

A32

Background: Approximately 7-10% of breast cancers and 10-15% of ovarian cancers are hereditary, the majority of which are caused by mutations in the BRCA1 and BRCA2 genes. Mutations in BRCA1 and BRCA2 are not unique to any one race or ethnicity. Currently, there are limited data available on the Hispanic American population's experience with BRCA genetic testing, and the utility of the BRCAPRO risk assessment model has not been evaluated in the Hispanic population. In this single institution study, our aim was to assess the performance of the BRCAPRO model in Hispanics who underwent genetic testing for BRCA1 and BRCA2. Materials and Methods: A total of 239 self-identified Hispanic individuals were evaluated for genetic risk assessment at MD Anderson Cancer Center's Clinical Cancer Genetics Program, of which 95 underwent BRCA genetic testing. After obtaining IRB approval, an analysis was performed to describe the mutational frequency and spectrum. In addition, BRCAPRO scores were calculated for the 78 Hispanics who were the first individual in their family to have genetic testing for BRCA1 and BRCA2. These values were then compared to the BRCAPRO scores of 79 randomly-selected Caucasians. The performance of the BRCAPRO model was evaluated by visually assessing the ROC curves and by calculating the area under the curve (AUC). Results: Of the 95 Hispanics who underwent genetic testing, 22 individuals were found to carry a deleterious mutation (15 BRCA1, 6 BRCA2, 1 with both BRCA1 and BRCA2), 9 were found to carry a variant of uncertain significance (5 BRCA1, 4 BRCA2), and 64 were found to be negative. Twenty-three different BRCA1 and BRCA2 mutations/variants were identified in Hispanics. When we evaluated the performance of the BRCAPRO model, we found that the model performed equally well in Hispanics as it did in Caucasians, with an area under the ROC curve of 0.774 in Hispanics and .770 in Caucasians. Discussion: A significant number of mutations/variants were identified in our Hispanic population. Our data support the use of the BRCAPRO model when assessing a Hispanic family's risk to carry a mutation in BRCA1 or BRCA2.