BREAST CHEMO RELIEF

Many can skip it

Most women with the most common form of early-stage breast cancer can safely skip chemotherapy without hurting their chances of beating the disease, a study has found. The study, which used genetic testing to gauge each patient’s risk, is the largest ever done of breast-cancer treatment. The results are expected to spare up to 70,000 patients a year in the United States the ordeal and expense of these drugs.

“The impact is tremendous,” said the study leader, Dr. Joseph Sparano of Montefiore Medical Center in The Bronx.

Most women in this situation don’t need treatment beyond surgery and hormone therapy, he said.

The study focused on women with early-stage cancer that has not spread to lymph nodes, is hormone-positive (meaning its growth is fueled by estrogen or progesterone) and is not the type that the drug Herceptin targets.

The usual treatment is surgery, then years of hormoneblocking drugs. But many women also are urged to have chemo to kill any stray cancer cells. Doctors know most don’t need it, but evidence is thin on who can forgo it.

The study gave 10,273 patients a test called Oncotype DX to estimate the risk that a cancer will recur. The test uses a biopsy sample to measure the activity of genes involved in cell growth and response to hormone therapy.

About 17 percent of women had high-risk scores and were advised to have chemo. The 16 percent with low-risk scores now know they can skip chemo, based on earlier results from this study.

The new results are on the 67 percent of women at intermediate risk. All had surgery and hormone therapy, and half also got chemo.

After nine years, 94 percent of both groups were still alive, and 84 percent were alive without signs of cancer. Adding chemo made no difference.

All women like those in the study should get gene testing to guide their care, said Dr. Richard Schilsky, chief medical officer of the American Society of Clinical Oncology.

Oncotype DX costs around $4,000, which Medicare and many insurers cover. Similar tests, including one called MammaPrint, also are widely used.

The study was funded by the National Cancer Institute, various foundations and proceeds from the US breast-cancer postage stamp. Some study leaders consult for breast-cancer drugmakers or the company that makes the gene test.

Results were discussed Sunday at the oncology society’s conference in Chicago and published by the New England Journal of Medicine.