No Benefit Seen in Extending Herceptin for Breast Cancer

One year of the drug was as effective as two in study of women with certain type of disease.

FRIDAY, Dec. 7 (HealthDay News) -- For women with a specific type of breast cancer, taking Herceptin for a year after initial treatment is just as effective -- and safer -- than staying on it for a longer period, new research suggests.

Many of the women in the study, who had HER2-postive early stage breast cancer, were cancer-free eight years later and experienced no major heart problems, the international study on Herceptin (trastuzumab) found.

"Giving trastuzumab for [two years] did not improve disease-free or overall survival, compared with one year of trastuzumab treatment," study author Dr. Martine Piccart, president of the European Society for Medical Oncology and chairwoman of the Breast International Group, said in a news release from the American Association for Cancer Research.

The study was run by the Breast International Group and Roche, the maker of Herceptin.

HER2-positive cancers are a particularly aggressive form of the disease and occur in 20 percent of breast cancer diagnoses, according to the U.S. National Cancer Institute.

The new phase 3 trial involved more than 5,000 women from several countries. After completing initial treatment for their early stage HER2-positive breast cancer, the women were randomly assigned to received Herceptin every three weeks for one year, two years or not at all.

Although the two-year treatment was no more effective than one year, heart problems occurred more frequently among the women who received Herceptin for the longer period. Most of the heart problems were reversible when the treatment was stopped, the researchers said.

The study proved "that a significant proportion of patients treated with trastuzumab ... are alive and free of disease recurrence after a median follow-up of eight years," said Piccart, who is chief of the medicine department at the Jules Bordet Institute in Brussels, Belgium.

"It is also reassuring with regard to the low cardiac toxicity of trastuzumab when given after adjuvant chemotherapy," she added. "Finally, it confirms that one year of adjuvant trastuzumab should remain the standard of care in women with HER2-positive early breast cancer."

The research was scheduled for Friday presentation at the 2012 San Antonio Breast Cancer Symposium. The data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The U.S. Centers for Disease Control and Prevention has more about breast cancer treatment.