Risk Assessment for Carriers of Variants of Uncertain Significance (VUS)

Women who carry inactivating mutations in the BRCAI and BRCA2 genes in their germline are at of significantly elevated risk of breast and ovarian cancer. Many mutation carriers are able to take advantage of surgical prevention options that dramatically reduce the risk of developing these cancers. However, many others are found to carry Variants of Uncertain Significance (VUS), which are predominantly missense mutations. Few of these VUS have been classified as cancer predisposing or neutral variants. Thus, many carriers of these VUS mutations do not know if they are at elevated risk of cancer. As a result many women carrying VUS that may be neutral unnecessarily undergo prophylactic surgery that is associated with significant long term side effects. Here we propose to determine the cancer relevance of VUS found throughout the BRCAI and BRCA2 genes by establishing genetic and laboratory assay based methods of VUS analysis. Specifically, in Aim 1 we will classify VUS using a series of studies focusing on family history of cancer of individuals with VUS and on breast tumor pathology of individuals with VUS. To facilitate this approach we have recently established the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA), a consortium aimed at classifying additional VUS through pooling of available family information from many research centers. Only through the data sharing proposed in ENIGMA will it be possible to classify a substantial number of additional mutations using genetic approaches. In Aim 2 we will focus on establishing the sensitivity and specificity of BRCA2 functional assays for classification of BRCA2 VUS. We will not study BRCAI because many of the variants in that gene have already been characterized by functional studies. By establishing the sensitivity and specificity of the assays relative to the genetic data from Aim 1 it may be possible to classify many additional VUS with insufficient family data for direct classification by genetic methods. In Aim 3, we will focus on developing methods for providing these results to providers and patients. This will involve evaluation of the current utilization of reclassification results, provision of results of reclassification efforts, provision of educational materials to improve this process, and evaluation of improvements in utilization of results.