New Drug Treatment Effective Against Some Breast Cancers

Oct. 19, 2005 — -- Knowing the news would change their lives forever, Sean Kearney decided not to immediately tell his wife about the results of her breast biopsy.

"He knew that if he told me, I'd never be able to get through the weekend," said Connie Kearney, of Beaver Falls, Pa. "It was homecoming weekend and our daughter was on the court. He knew I'd want to enjoy the weekend with her."

But three days later, Connie learned from Sean that she did indeed have breast cancer. So, in October of last year, she underwent surgery, radiation and several weeks of chemotherapy. As she completed therapy, her doctor approached her about enrolling in a clinical trial to test the effects of an experimental medication named Herceptin.

"I had to try anything they offered me," Connie, 46, said. "It's not just me, I've got a family … four kids to think about."

Hope for Those With 'HER2-Positive' Cancer

She didn't know it at the time, but she was given a treatment option that new research shows may have drastically reduced her chances of dying.

In a study published in the Oct. 20 issue of the New England Journal of Medicine, researchers from cancer centers around the world evaluated the effects of adding Herceptin to the treatment of women diagnosed with HER2-positive breast cancer.

Overall, the study showed that the women who received Herceptin reduced their chance of dying by 33 percent, and these results were so promising that trial was ended early so all eligible women could have the chance to take Herceptin.

Put another way, at three years into the study, 87 percent of the women who received Herceptin were cancer-free, while 75 percent of the women who did not receive the drug were cancer-free. At four years, 85 percent of the Herceptin group still remained disease-free while only 67 percent of the women who didn't receive the medication were.

HER2 is a gene that regulates cell growth. Women are diagnosed with that form of cancer if testing reveals that they have either extra copies of the gene that makes HER2 or a single but overactive gene. It's estimated that between 15 percent and 20 percent of invasive breast cancers are HER2 positive.

All of the 3,351 women in the study were given standard medical treatment that generally included surgery, radiation and chemotherapy. But 1,672 of the women received 52 weeks of Herceptin, clinically known as trastuzumab. Trastuzumab is an antibody that sticks to the HER2 receptor and prevents it from allowing the cancer cells to grow. It is manufactured by the drug company Roche, which funded the study.

"It was exhilarating ... the magnitude of difference between the two groups is very exciting," said Dr. Charles Geyer, director of Medical Breast Oncology at Allegheny General Hospital in Pittsburgh. Geyer was one of the study's lead authors.

Dr. Clifford Hudis, chief of the Breast Cancer Medicine Service at Memorial Sloan-Kettering Cancer Center in New York, estimated that the findings would influence the care of about 25 percent of women who have been newly diagnosed with invasive breast cancer. The findings do not apply to an earlier stage of breast cancer known as ductal carcinoma in situ.

The study noted that Herceptin does carry risks, particularly for the cardiovascular system. So, prior to starting Herceptin therapy, study participants underwent extensive cardiac testing to make sure their hearts were healthy. Still, 51 of the women who received Herceptin developed congestive heart failure while five of the women in the other group did. However, for those who did suffer heart damage, many regained normal heart function eventually.

Though he recommends the medication for most patients with HER2-positive disease, Dr. Eric Winer of the Dana-Farber Cancer Institute in Boston said it wouldn't likely benefit women with very small tumors and cancer that hasn't spread to the lymph nodes.

But it likely did benefit Kearney, who now considers herself lucky for being in the trial.

"This is what you hope for ... maybe it's why I'm here today," she said.