A genetic marker has been discovered that will help accurately profile which women were more likely to have their breast cancer return years later.
The clinicopathological characteristics of breast cancer tumors remain imperfect prognostic classifiers, in part due to the molecular heterogeneity of breast cancer, as the predictive factors that utilize tumor-based markers are not optimal determinants of risk of breast cancer recurrence (BCR).
Medical Scientists at the University of Alberta (Edmonton, AB, Canada) scanned the entire human genome of 369 women who had been diagnosed with breast cancer. Of those, 155 had their cancer recurrence and 214 did not. DNA was extracted from the buffy coat fractions using commercially available DNA isolation kits (Qiagen; Mississauga, Ontario, Canada). Whole genome genotyping was conducted using the Genome-Wide Human Single Nucleotide Polymorphisms (SNP) Array 6.0, (Affymetrix; Santa Clara, CA, USA) which consisted of over 1.8 million probes consisting of 906,600 SNP and 946,000 copy number probes, with an overall inter-marker distance of 680 base pairs (bp).
The scientists identified ten germline copy-number aberrations (CNAs) as potential prognostic factors for disease recurrence in the early-stage nonmetastatic breast cancer. These germline signatures were particularly relevant to the luminal A subtype as large number of breast cancer cases with luminal A tumors experience disease recurrence despite their good prognosis based on tumor characteristics.
Sambasivarao Rao Damaraju, PhD, of the Cross Cancer Institute (Edmonton, AB, Canada) and the senior author said, "If we can accurately predict which women are at high risk of breast cancer recurrence, it gives the physicians and oncologists treating those women time to design a more aggressive therapy in hopes of preventing the cancer from coming back. The accuracy of prognosis could be improved by complementing tumor based markers with the DNA marker that can be found through a simple blood test." The study was published on January 16, 2013, in the journal Public Library of Science One