The performance of the models can vary in specific ethnic groups. The BRCAPRO model appeared to best fit a series of French Canadian families. There have been variable results in the performance of the BRCAPRO model among Hispanics,[96,97] and both the BRCAPRO model and Myriad tables underestimated the proportion of mutation carriers in an Asian American population. Further information is needed to determine which model performs best in each ethnic group.
Table 2. Characteristics of Common Models for Estimating the Likelihood of a BRCA 1/2 Mutation
AJ = Ashkenazi Jewish; BOADICEA = Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm; BRCAPRO = Berry-Aguilar-Parmigiani Model; FDR = first-degree relatives; SDR = second-degree relatives.
|�||Myriad Prevalence Tables||BRCAPRO [71,93]||BOADICEA [71,83]||Tyrer-Cuzick |
|Method||Empiric data from Myriad Genetics based on family and personal history reported on requisition forms||Statistical model||Statistical model||Statistical model|
|Features of the Model||Proband may or may not have breast or ovarian cancer ||Proband may or may not have breast or ovarian cancer||Proband may or may not have breast or ovarian cancer||Proband must be unaffected |
|Considers age of breast cancer diagnosis as <50 y, >50 y ||Considers exact age at breast and ovarian cancer diagnosis||Considers exact age at breast and ovarian cancer diagnosis ||Also includes reproductive factors and body mass index to estimate breast cancer risk |
|Considers breast cancer in ?1 affected relative only if diagnosed <50 y ||Considers prior genetic testing in family (i.e., BRCA1/BRCA2 mutation-negative relatives) ||Includes all FDR and SDR with and without cancer ||�|
|Considers ovarian cancer in ?1 relative at any age ||Considers oophorectomy status ||Includes AJ ancestry ||�|
|Includes AJ ancestry ||Includes all FDR and SDR with and without cancer ||�||�|
|Very easy to use ||Includes AJ ancestry ||�||�|
|Limitations||Simplified/limited consideration of family structure||Requires computer software and time-consuming data entry ||Requires computer software and time-consuming data entry||Designed for individuals unaffected with breast cancer |
|Early age of breast cancer onset ||Incorporates only FDR and SDR; may need to change proband to best capture risk and to account for disease in the paternal lineage ||Incorporates only FDR and SDR; may need to change proband to best capture risk ||�|
|�||May overestimate risk in bilateral breast cancer ||�||�|
|�||May perform better in Caucasians than minority populations [97,101]||�||�|
Genetic testing for BRCA1 and BRCA2 mutations has been available to the public since 1996. As more individuals have undergone testing, risk assessment models have improved. This, in turn, gives providers better data to estimate an individual patient's risk of carrying a mutation. There remains an art to risk assessment. There are factors that might limit the ability to provide an accurate risk assessment (i.e., small family size, paucity of women, or ethnicity) including the specific circumstances of the individual patient (such as history of disease or prophylactic surgeries).