The Value of Single Nucleotide Polymorphisms in Projecting Breast Cancer Risk

• Activity Number: 191
• Type: Invited
• Date/Time: Monday, August 3, 2009 : 2:00 PM to 3:50 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Mitchell H. Gail*+ and Ruth Pfeiffer
• Companies: National Cancer Institute and National Cancer Institute
• Keywords: Cumulative risk ; Discriminatory accuracy ; Evaluating risk models ; Breast cancer ; Medical decision analysis ; Genetic marker

Abstract

Seven single nucleotide polymorphisms (SNPs) have recently been confirmed to be associated with breast cancer. We assessed the value of adding these SNPs to the Breast Cancer Risk Assessment Tool (BCRAT), which is based on standard risk factors such as family history. The model with these SNPs (BCRATplus7) had an area under the receiver operating characteristic curve (AUC) of 0.632, compared to 0.607 for BCRAT.. We also assessed how much BCRATplus7 reduced expected losses, compared to BCRAT, in deciding whether a woman should take tamoxifen to prevent breast cancer, in deciding whether a woman should have a mammogram, and in allocating a scarce public health resource, such as access to mammography. In none of these applications did BCRATplus7 outperform BCRAT substantially. Hundreds of such SNPs would be needed to achieve high discriminatory accuracy.