PITTSBURGH (KDKA) – Can breast cancer recurrence be predicted? Typically doctors use tumor size, spread, and what it looks like under the microscope.
“Based on that information,” says Allegheny General Hospital Breast Cancer Geneticist Dr. D. Lawrence Wickerham, “We’ve been able to be reasonably certain about broad categories of prognosis.”
But it turns out the tumor’s genetic signature gives an even more accurate glimpse into the future.
“[It’s] an additional step to personalize breast cancer treatment,” Dr. Wickerham said.
Researchers studied three genetic signature tests on the tumors of more than 600 post-menopausal women with estrogen receptor positive breast cancer who were treated with the drugs tamoxifen and anastrazole. From their tumor specimens, the cancer DNA was decoded in a lab.
While all three tests were predictive, one called the Breast Cancer Index was most predictive of recurrence five to ten years later.
“The test itself is new. It’s not commercially available. We’ll need additional validation, repeat testing to make sure it’s accurate, but it clearly has promise,” Dr. Wickerham said.
Right now, more than half the patients with the estrogen receptors who are treated with these drugs will have a recurrence after five years.
For that reason, nearly all women with this type of cancer receive hormonal therapy for ten years. If this new test becomes available, it could predict which ones can have a shorter course of what can be expensive medicine.
“With this test, we could potentially stop treatment in 60 percent of the women in five years,” Dr. Wickerham said. “For the other 40 percent at increased risk, we could convince them that taking this medication is the right thing for them to do.”