Breast cancer patients can skip chemo, opt for lighter treatment: studies
Thousands of breast cancer patients each year could be spared chemotherapy or get gentler versions of it without harming their odds of beating the disease, new research suggests.
One study found that certain women did better — were less likely to die or have a relapse — if given a less harsh drug than Adriamycin, a mainstay of treatment for decades.
Another study found that a gene test can help predict whether some women need chemo at all— even among those whose cancer has spread to their lymph nodes, which currently typically leads to full treatment.
The findings are sure to speed the growing trend away from chemo for many breast cancer patients and targeting it to a smaller group of women who truly need it, doctors said Thursday at the San Antonio Breast Cancer Symposium, where the studies were reported.
"We are backing off on chemotherapy and using chemotherapy more selectively" in certain women, said Dr. Eric Winer of the Dana-Farber Cancer Institute in Boston.
Gene test predictive
The gene test in particular "will start changing practice nearly immediately," said Dr. Peter Ravdin of the University of Texas M.D. Anderson Cancer Center in Houston. "The results are compelling that this test … helps select patients who will most benefit from chemotherapy."
Breast cancer is the most common major cancer in American and Canadian women.
More than 178,000 new cases are expected in the U.S. this year, and 22,300 in Canada. Most are helped to grow by estrogen, and hormone-blocking medicines like tamoxifen are used to treat those types.
Chemotherapy usually is added if the disease has spread to lymph nodes — a situation faced by about 45,000 U.S. women each year. Doctors know that chemo won't help most of these women, but they have had no good way to tell who can safely skip its cost and misery.
Oncotype DX, a test that measures the activity of 21 genes and gives a score to predict a woman's risk of recurrence, has been used for several years to guide treatment for certain women with early breast cancers, especially those that have not spread.
The new study, led by Dr. Kathy Albain of Loyola University, looked at whether it accurately predicted chemotherapy's benefit in 367 women whose hormone-driven cancer had spread to lymph nodes.
A decade after these women were treated, those who had low scores on the gene test were found to have had no benefit from chemo. Conversely, chemo did a lot of good for those with high scores.
Because 40 per cent of the women scored low, it means that as many as 18,000 women each year might safely skip chemo.
The National Cancer Institute and the test's maker, Genomic Health of Redwood City, Calif., sponsored the study. Albain, Winer and Ravdin have consulted or been paid speakers for the company in the past.
Dr. Kelly Marcom, a Duke University cancer expert with no ties to the company, said the test would give valuable information to guide treatment for more patients in the future. He has used it on about 50 women in the last year.
"I've had it cut both ways" — ruling chemo in and out, Marcom said.