New research finds a genetic test can predict, for some patients, whether breast cancer will return after treatment. The study in the New England Journal of Medicine provides more evidence that treatment for breast cancer should be individualized instead of just the standard chemotherapy.
"The test told me that it would be less than 1 percent that the chemo would really help me, so I was very glad to hear that and I decided not to do chemotherapy," says Susan Laporta, a breast cancer patient.
Tumor samples were analyzed to determine the expression of 21 key genes. Researchers say the predictions held regardless of a patient's age or tumor size. Researchers tested key genes in tumor samples from over 400 patients with estrogen dependent breast cancer that hadn't spread to the lymph nodes. Based on the test, the patients were ranked as either low, intermediate or high risk for recurrence. The test was actually approved for use by the FDA in February. But now, after ten years of study, researchers say they know their predictions were accurate in identifying early which patients could be helped by chemotherapy and those for whom the side effects may not be worth the effort.
Women ranked as low risk had a 6% recurrence rate after ten years, intermediate patients a 7% rate of recurrence and high risk women had a 30% recurrence rate. Experts say the findings are evidence that breast cancer treatment is moving toward individualized care. About a quarter of the women in the study were classified as high-risk for recurrence. These women had the most benefit from chemo. Low risk women made up about half of the patients, these women had minimal chemo benefits now working to determine whether chemo is harmful to the low-risk group.
The study was presented Friday at the San Antonio Breast Cancer Symposium.