TEST FINDS WHICH BREAST CANCER PATIENTS CAN SKIP CHEMOTHERAPY

Many women with earlystage breast cancer can skip chemotherapy without hurting their chances of beating the disease, a major new study has found.

The 21-gene test accurately identified a group of women whose cancers are so likely to respond to hormoneblocking drugs that adding chemo would do little, if any, good while also exposing them to side effects and other risks, the researchers found.

“You can’t do better than that,” says the study leader, Dr. Joseph Sparano of Montefiore Medical Center in New York.

An independent expert, Dr. Clifford Hudis of New York’s Memorial Sloan Kettering Cancer Center, agreed.

“There is really no chance that chemotherapy could make that number better,” Hudis says.

Using the gene test “lets us focus our chemotherapy more on the higher-risk patients who do benefit” while sparing others the ordeal, says Hudis.

“This should provide a lot of reassurance to women and their physicians,” says Dr. Kathy Albain of Loyola University Medical Center in Maywood, who was among the other authors of the multi-center study sponsored by the National Cancer Institute. “The test provides us with greater clarity of who can safely avoid chemotherapy.”

The study was published by the New England Journal of Medicine.

It 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.

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 might have spread and could seed a new cancer later.

Doctors know that most of these women don’t need chemo, but there have been no great ways till now to tell who can safely skip it.

A California company, Genomic Health Inc., has been selling the multigene test, called Oncotype DX Recurrence Score, since 2004 to help gauge this risk. The test measures the activ- ity of genes that control cell growth and others that indicate a likely response to hormone-therapy treatment.

Past studies have looked at how women classified as low-, intermediate- or highrisk by the test have fared. The new study is the first to assign women treatments based on their scores and to track recurrence rates.

Of the 10,253 women in the study, including 41 at Loyola, 16 percent were classified by the test as low-risk, 67 percent as intermediate- and 17 percent as high-risk for recurrence.

The high-risk group was given chemotherapy and hormone-blocking drugs. Women in the middle group were randomly assigned to get just the standard hormone therapy or to add chemo. Results on these groups are not yet ready — the study is continuing.

But independent monitors recommended the results on the low-risk group be released now because it was clear that adding chemo wouldn’t improve their fate.

After five years, about 99 percent hadn’t relapsed, and 98 percent were alive. About 94 percent were free of any invasive cancer, including new cancers at other sites or in the opposite breast.