"It works and it works great. It has really changed the way we manage a substantial proportion of our breast cancer patients," says Susan K. Boolbol, MD, chief of breast surgery at Beth Israel Medical Center in New York City.
Boolbol tells WebMD that after the diagnosis itself, "getting chemotherapy and losing their hair is the biggest concern" of women with breast cancer.
The findings were presented at the American Society of Breast Surgeons (ASBS) Ninth Annual Meeting.
Moving Away From One-Size Fits All
The test is used to help guide the treatment of estrogen-fueled breast cancers that have not spread to the lymph nodes. Nearly half of the 182,000 invasive breast tumors that will be diagnosed in the U.S. this year fall into that category.
In the past, about 90% of women with so-called estrogen-dependent, lymph-node negative breast cancer were given chemotherapy to reduce the odds of the cancer returning, says Nashville Breast Center's Pat Whitworth, MD, chairman of the board at the ASBS.
"We couldn't identify who would benefit from treatment, so we had to treat everyone," he tells WebMD.
Enter OncoType DX, which measures the activity of 21 genes that can raise breast cancer risk. Based on their activity, women are assigned a recurrence score: low, medium, or high risk of recurrence.
Studies have shown that women who fall into the low-risk category gain little, if any, benefit from chemotherapy. Based on those studies, recently updated guidelines recommend that the test be incorporated into the care of some women with breast cancer.
"It's really helping to individualize therapy," Whitworth says.
Studies Show Test Spares Women From Chemo
One study presented at the meeting involved 18 premenopausal and 60 postmenopausal women with estrogen-dependent, node-negative breast cancer.
"Prior to Oncotype DX, 39 of the 78 women, or 50%, would have been given chemotherapy," says Leila C. Thanasoulis, MD, a fellow in surgical oncology at Bryn Mawr Hospital in Pennsylvania.
With Oncotype DX, chemotherapy was recommended for only nine of the 78, or 12% of the women.
The cost savings: nearly $7,000 per woman, Thanasoulis tells WebMD.
The second study involved 66 women with estrogen-fueled tumors that hadn't spread to the lymph nodes.
"The recurrence score influenced our treatment decision in 44% of them," says Juhi Asad, MD, a fellow in the department of surgery at St. Luke's-Roosevelt Hospital in New York City.