Women diagnosed with a common type of breast cancer now have a more effective, safer drug for follow-up care intended to prevent the disease from returning or spreading, according to a national study.
The study, released Saturday, found that anastrozole was more effective than tamoxifen, the medication of choice for the past 10 or 15 years, to prevent additional episodes of cancer in post-menopausal women already treated for the ductal cancer known as DCIS. The study was described as the first to compare the medications’ use in patients with DCIS.
“The bottom line is that this changes the way we treat” DCIS, said Adam Brufsky, a study co-author and co-director of the University of Pittsburgh Medical Center’s Comprehensive Breast Cancer Center.
The study “has tremendous merit,” said Thomas Julian, division director of breast surgical oncology for the Allegheny Health Network, noting as many as 50,000 women are diagnosed with DCIS each year. The drug especially benefited women younger than 60, he said.
The federally supported study is to be presented Monday at a meeting of the American Society of Clinical Oncology in Chicago.
The study involved 3,104 patients from Pittsburgh and other cities who were post-menopausal and diagnosed with a form of DCIS stimulated by estrogen. Each had a lumpectomy and radiation. After 10 years, 93.5 percent of those taking anastrozole remained cancer-free, compared with 89.2 percent of those taking tamoxifen, a difference described as statistically significant.
Tamoxifen blocks estrogen from attaching to cancer cells, while anastrozole suppresses the body’s hormone production.
“The good news is, tamoxifen and anastrozole are both very effective. But it seems that women have better chances of staying well with anastrozole,” the lead author, Richard G. Margolese, professor of surgical oncology at Jewish General Hospital at McGill University in Montreal, said in a statement.
Effectiveness isn’t the only benefit, said Ms.Julian and Lawrence Wickerham, chief of cancer Genetics at Allegheny General Hospital. Anastrozole doesn’t carry tamoxifen’s elevated risk of uterine cancer or blood clots.
“We always try to find new and improved treatments,” Wickerham said. “New and improved can be more effective, but it also can mean fewer and less severe side effects.”
Anastrozole does carry an increased risk of osteroporosis. But that would not necessarily keep a patient from taking the medication.
“We have a series of compounds that prevent osteoporosis,” said Brufsky, professor of medicine at the University of Pittsburgh and associate director of clinical investigations at Pitt’s Cancer Institute.