A consortium of US scientists has reported that an easy-to-perform analysis of 50 genes can reliably sort breast cancer tissue samples by type and predict which therapies are most likely to work.
Philip Bernard, Joel Parker, Matthew Ellis and many others published the heartening findings in the Journal of Clinical Oncology.
“Unlike a widely used genomic test that applies only to lymph-node negative, estrogen-receptor positive breast cancer, this new genomic test is broadly applicable for all women diagnosed with breast cancer,” Ellis, a breast cancer expert from Washington University told BurrillReport.
To develop and validate the 50 gene test, the scientists reviewed more than 1,000 breast cancer tissue specimens. They were able to establish a genetic signature for each major form of breast cancer: luminal A, luminal B, basal-like and HER2-enriched.
Then, having accurately classified 133 consecutive tissue specimens using their tool, the scientists assessed how the different breast cancer phenotypes responded to chemotherapy.
The test turned out to be highly predictive of chemotherapy response, and superior to currently used tests like estrogen and progesterone receptor status and HER2 gene expression status.
For example, patients with luminal A cancers did not respond to chemotherapy, suggesting that they ought to forgo chemotherapy in lieu of hormone-based treatment.
Conversely, basal-like breast cancer, which carries an ominous prognosis, turned out to be “the most sensitive to chemotherapy. By identifying (the cancer types correctly) we can ensure they are treated adequately,” Ellis said.
The scientists are now studying how each breast cancer type responds to the 20 or so chemotherapeutic drugs on the market.
When it’s ready, the new genomic test will be marketed by University Genomics, which is owned by Washington University, the University of Utah and the University of North Carolina.