With new test, many women with early breast cancer can skip chemo
|
Version 0 of 1. Many women with early-stage breast cancer can skip chemotherapy without hurting their odds of beating the disease, according to a major study that shows the value of a gene-activity test for gauging a patient’s risk. The test accurately identified a group of women whose cancers were so likely to respond to hormone-blocking drugs that adding chemo would do little if any good while exposing them to side effects and other health risks. In the study, women who skipped chemo based on the test had less than a 1 percent chance of having cancer recur in places such as the liver or lungs within the next five years. “You can’t do better than that,” said the study leader, Joseph Sparano of Montefiore Medical Center in New York. Clifford Hudis of Memorial Sloan Kettering Cancer Center, who wasn’t involved with the study, agreed and said using the gene test “lets us focus our chemotherapy more on the higher-risk patients who do benefit” and spare others the ordeal. The study involved the most common type of breast cancer: early-stage, without spread to lymph nodes; hormone-positive, meaning the tumor’s growth is fueled by estrogen or progesterone; and not the type that the drug Herceptin targets. Each year, more than 100,000 women in the United States are diagnosed with this form of cancer. The usual treatment is surgery followed by years of a hormone-blocking drug. But many women also are urged to have chemo, to help kill any stray cancer cells that may have spread beyond the breast and could seed a new cancer later. Doctors know that most of these women don’t need chemo, but there has been no conclusive way to tell who can safely skip it. To help gauge this risk, a California company, Genomic Health, has sold a test called Oncotype DX since 2004. The test measures the activity of genes that control cell growth and of others that indicate a likely response to hormone therapy treatment. Of the 10,253 women in the study, 16 percent were classified as at low risk, 67 percent as at intermediate risk and 17 percent as at high risk for recurrence by the test. The high-risk group was given chemotherapy and hormone-blocking drugs. Women in the middle group were randomly assigned to get hormone therapy alone or to hormones with add chemo. These two parts of the study are continuing. But independent monitors recommended that the results about the low-risk group be released, because it was clear that adding chemo would not improve their fate. |