Aug. 1, 2012 -- Older women with the most common type of metastatic breast cancer may soon have a new treatment option that may improve their survival.
A new study shows that postmenopausal women with advanced disease treated with a combination of two anti-estrogen therapies lived longer than women who took one drug followed by another.
The study is the first to show that combination hormonal therapy can slow disease progression and improve survival in advanced breast cancer, says researcher Kathy Albain, MD, of Loyola University Medical Center.
The research appears in the Aug. 2 issue of the New England Journal of Medicine.
"This is exciting because we have not seen progression-free survival of this length or any length in these women with previous treatments," she tells WebMD.
Both drugs are widely used to treat breast cancer, although not at the same time.
Taken by pill, Arimidex works by decreasing the amount of estrogen the body produces.
Given by injection, Faslodex helps to get rid of estrogen receptors and blocks the hormone's effect on cancer cells.
About half the women in the study received standard treatment with Arimidex followed by Faslodex if their disease progressed. The rest took the two drugs together from the time they enrolled in the trial.
Compared to women in the standard treatment group, women who took the combination therapy survived about six months longer -- meaning that for some women the benefit was even greater.
The combination therapy also appeared to slow the progression of their disease and it was well tolerated with a side effect profile similar to that of single-drug treatment.
Three years into the trial, women taking the combination therapy were 13% more likely to have stable disease with no evidence of progression, Albain says.
Combo Treatment May Work for Early Disease
The researchers believe the two drugs' different modes of action may explain why they seem to work better in combination than on their own.