Trial Uses Genetic Test to Tailor Breast Cancer Treatment

Cincinnati—Researchers believe a genetic test used to calculate a woman’s risk for breast cancer recurrence may also help determine if a subset of patients would be better off with less aggressive therapy following surgery.

According to Jennifer Manders, MD, it is not always clear which follow-up treatment—chemotherapy, hormone therapy or a combination of both—is most effective for women who fall into the gray area of “intermediate risk” for breast cancer recurrence.

Currently, many patients with early stage breast cancer are given both hormones and chemotherapy to control recurring tumor growth and kill any residual cancer cells in the body.

Research suggests, however, that chemotherapy could have no measurable benefit to patients with less-aggressive cancers whose risk for recurrence is unclear.

A major phase-3 trial, led locally by surgeons Elizabeth Shaughnessy, MD, PhD, and Manders, is underway to investigate whether hormone therapy alone can produce better cancer-free survival for women who fall into the intermediate recurrence risk category.

“Research tells us that giving hormone therapy alone to women at low risk for recurrence and chemotherapy followed by hormonal therapy to women at a high risk for recurrence makes medical sense—it’s the women who fall in the middle that we’re unclear about,” explains Manders, an assistant professor at the University of Cincinnati (UC).

“We need to develop a method of tailoring follow-up treatment that addresses the specific characteristics of a patient’s tumor,” she adds. ”This will allow us to more accurately predict what medical treatments will be most effective at alleviating the disease long term.”

This National Cancer Institute-sponsored trial—known as TAILORx—uses genetic tests to obtain an individualized and quantitative analysis of how likely a specific patient’s breast cancer is to recur.

When a patient enrolls in the trial, a tumor tissue sample is sent to a central processing lab where scientists analyze it against a panel of 21 genes with known links to breast cancer.

Using a statistical risk prediction model, the scientists then calculate a “score” that represents the specific patient’s risk for breast cancer recurrence. The score is determined from the gene expression results using a range of zero to 100. Scores between 11 and 25 are considered to be in the intermediate or unclear risk category this trial focuses on.

Manders says information gathered from the genetic breast cancer test could give physicians a better understanding of the specific characteristics of their patients’ breast tumors, which is critical in planning accurate treatment plans and follow-up.

“This trial asks: will the majority of women in that moderate risk group will benefit from chemotherapy, hormonal therapy or a combination of both?” says Manders. “If we can answer that question, we can customize treatment based on a tumor’s specific characteristics and apply more logical medical regimens that minimize unnecessary treatment—and the correlating potential side effects.”

Study participants are placed into one of four treatment arms, based on their recurrence scores. Women considered at low risk (10 or less) will receive hormone therapy, with women on the other end of the scale (26 or more) will get both chemotherapy and hormone therapy. The remaining women falling into the intermediate risk group will be randomized to receive either hormone therapy alone or a combination of chemotherapy plus hormone therapy.

Women who have undergone surgery for localized stage 1 or 2 hormone receptor-positive breast cancer may be eligible for the trial.

Some insurance providers, including Medicare, provided coverage for genetic testing. Patients who qualify for this trial will receive the genetic testing and corresponding treatment visits at no cost.

For enrollment information, call Ruth Steele at (513) 584-2951.