The study found that combining two drugs that normally are given as single agents significantly extended the lives of women with metastatic breast cancer. Kathy Albain, MD, a breast cancer specialist at Loyola University Medical Center, is among the main authors of the study.
The study found that women who initially took the drugs anastrozole and fulvestrant together lived more than six months longer than women who took anastrozole alone, with fulvestrant given later when the disease progressed.
“This study is the first to show that combination hormonal therapy alone without chemotherapy improves survival in advanced breast cancer,” Albain said. “This most likely will change the standard of care for how we treat these patients.”
First author is Rita Mehta, MD, of the University of California at Irvine.
Anastrozole (brand name, Arimidex®) is a pill that is taken daily. It is in a class of medications called aromatase inhibitors. It works by decreasing the amount of estrogen the body makes. (Estrogen fuels breast cancer.) Fulvestrant (brand name Faslodex®) is given by injection. It binds to estrogen receptors, thereby blocking the effect estrogen has on cancer cells.
The study included 707 postmenopausal women who had metastatic breast cancer that was hormone-receptor-positive. About half the women were randomly assigned to receive the standard regimen: treat first with anastrozole, and after the disease progresses, switch to fulvestrant. The other half were randomly assigned to receive anastrozole and fulvestrant in combination.
Women who received the standard regimen survived a median of 41.3 months. Women who received the two drugs in combination survived a median of 47.7 months.
Among women who received the standard regimen, it took a median of 13.5 months for the disease to progress. Among those who received the drugs in combination, it took 15 months before the disease progressed.
The combination treatment produced even greater benefits among women who had not previously taken tamoxifen.
Side effects generally were similar in both treatment groups, although only the combination group experienced the most severe side effects (one stroke and two pulmonary embolisms).
Albain is a professor in the Department of Medicine, division of Hematology/Oncology, at Loyola University Chicago Stritch School of Medicine.
The study was conducted by the SWOG national clinical trials network and supported by grants from the National Cancer Institute and AstraZeneca.
Based in the western suburbs of Chicago, Loyola University Health System is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and 28 primary and specialty care facilities in Cook, Will and DuPage counties. The medical center campus is conveniently located in Maywood, 13 miles west of the Chicago Loop and 8 miles east of Oak Brook, Ill. The heart of the medical center campus, Loyola University Hospital, is a 569-licensed-bed facility. It houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children’s Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as the LUC Stritch School of Medicine, the LUC Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola’s Gottlieb Memorial Hospital campus in Melrose Park includes the 264-bed community hospital, the Gottlieb Center for Fitness and the Marjorie G. Weinberg Cancer Care Center.