A Major Advance on Breast Cancer

A drug that targets only diseased cells has proven effective against an aggressive form of early breast cancer - a long-sought breakthrough that has doctors talking about helping thousands of women each year in this country alone.

The drug, Herceptin, is already used or advanced cancer. But in three studies involving thousands of women with early-stage disease, it cut the risk of a relapse in half. The drug is part of a regimen of care - from early detection to chemotherapy - that in recent years has made breast cancer a highly treatable disease. It is still too early to assess Herceptin's true worth, because the women studied were followed for only three years at the most, said Debbie Saslow, director of the breast-cancer section of the American Cancer Society.

Moreover, Herceptin is only for the estimated 20 percent of breast-cancer cases in which tumors churn out too much of a protein known as HER2. Even then, the drug does not help everyone. Still, Herceptin could be the biggest addition to cancer care since research a decade demonstrated the extraordinary effectiveness of tamoxifen, another medicine that transformed the treatment of the disease by homing in on cancer cells but sparing healthy ones.

Herceptin, made by Genentech, appears to have helped change "one of the most worrisome kinds of cancers into one that may have a relatively good prognosis," said Ed Romond of the University of Kentucky. Genentech intends to apply to the U.S. government to add early-stage cancer use to Herceptin's label, spokeswoman Colleen Wilson said. Doctors are already free to prescribe the drug for early breast cancer on their own authority.

About 200,000 women are diagnosed with breast cancer each year in this country, and 40,000 die. About 30,000 American women will probably be taking Herceptin for breast cancer within a couple of years, curing perhaps 7,000 who would otherwise relapse, doctors predicted. However, doctors cautioned that some women get better without Herceptin, especially when there is little evidence that the cancer is spreading within the breast. Also, a small number taking the drug suffer heart failure.

A year of Herceptin could cost $48,000 even at wholesale prices. It is also unclear whether Herceptin should be taken with chemotherapy drugs, soon afterward, or even years later. Herceptin appears so potent, some researchers said, that patients might someday be able to skip chemotherapy, radiation and surgery, which destroy both healthy and diseased tissue.