Myriad Validates Polygenic Score to Predict Breast Cancer Risk in Women of Hispanic Ancestry Who Test Negative for Hereditary Cancer Mutations

Myriad Genetics, Inc a leader in molecular diagnostics and personalized medicine, today announced results from an important study to validate the polygenic component of a forthcoming riskScore™ test for Hispanic women who test negative for a hereditary cancer mutation with the myRisk® Hereditary Cancer test.  The results are being presented at the 2018 San Antonio Breast Cancer Symposium (SABCS) in San Antonio, Texas.

“A year ago, we launched riskScore as a significant enhancement to myRisk® to provide women of European ancestry with additional genetic information about their lifetime risk of developing breast cancer,” said Jerry Lanchbury, Ph.D., chief scientific officer, Myriad Genetics.  “This year we are excited to presents results from almost 14,000 women which is the largest polygenic study ever conducted for Hispanic ancestry.  It is another step in our commitment to make riskScore accessible to all women, including those most underrepresented in our health care system.”

Graph 1: Polygenic Score Accurately Predicts Risk of Breast Cancer in Unaffected Hispanic women with a Negative myRisk® Hereditary Cancer Test Result

This study evaluated 87 single nucleotide polymorphisms (SNPs) as breast cancer risk factors through the validation of a polygenic score in 8,487 women of Hispanic ancestry.  The results show that the 87-SNP polygenic score was highly predictive of breast cancer risk in unaffected Hispanic women with a significant family cancer history who tested negative for germline mutations in known breast cancer risk genes (p=7.1x10-19).  Estimates of relative risk due to SNPs ranged from 0.2 to 3.6 (Graph 1). The clinical implementation of riskScore for women of Hispanic ancestry may significantly improve the management of high-risk Hispanic women who test negative for mutations in with the myRisk Hereditary Cancer test.

“In this study, we identified a novel SNP-based polygenic score that provides significant breast cancer predictive value in individuals of Hispanic ancestry,” said Lanchbury.  “Our next task is to validate the combination of the polygenic score with the Tyrer-Cuzick model in Hispanic women.”