New test to spot breast cancer patients most at risk

Scientists have developed a new test that can identify patients with the most lethal forms of triple-negative breast cancer, a disease which requires aggressive and innovative treatment.
Triple-negative breast cancers tend to be aggressive cancers with a poor prognosis. They lack three primary components - the estrogen receptor, the progesterone receptor and a protein called HER2 - that are the targets of effective therapies with few side effects.
The new test was able to distinguish between patients with a good or poor prognosis, even within groups of patients already stratified by existing tests such as MammaPrint and Oncotype.
"We were able to detect bad guys hiding among the good guys," said study author Marsha Rosner, professor in the Ben May Department for Cancer Research at the University of Chicago.

"When we applied our approach to clusters of patients sorted by the existing tests, we could spot exceptions," Rosner said.
The researchers studied genetic pathways around a gene known as RKIP (Raf Kinase Inhibitory Protein) to generate prognostic gene signatures.

This RKIP-based pathway suppresses metastasis, the spread of cancer to distant sites, leading them to the BPMS (BACH1 Pathway Metastasis Signature).
The researchers mapped out a series of testable genetic signals, involving about 30 genes, and correlated the combination of signals with long-term outcomes in about 1,600 breast cancer patients.
They found that variations in the BPMS could predict prognosis for a wide array of patients, especially those with advanced or triple-negative disease.

"Specifically, BPMS can significantly differentiate between higher and lower risk patients with the highly aggressive basal subtype," the authors wrote in the journal PLOS ONE.
The test was particularly informative for patients with triple-negative disease, where it could estimate the odds of a cancer spreading to other sites.