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Name of the Trial

Phase III Randomized Study of Anastrozole With or Without Fulvestrant as First-Line Therapy in Postmenopausal Women With Metastatic Breast Cancer (SWOG-S0226). See the protocol summary ³.

Principal Investigators

Dr. Rita S. Mehta Principal Investigator

Dr. Rita S. Mehta, Southwest Oncology Group, and Dr. Theodore Vandenberg, National Cancer Institute of Canada.

Why Is This Trial Important?

In women with breast cancer, cancer cell growth may be promoted by estrogen (referred to as hormone-sensitive disease). Postmenopausal women whose tumors are hormone sensitive often take an antiestrogen drug following initial treatment of their cancer. The most common antiestrogen drug used is tamoxifen, which blocks the binding of estrogen to its receptors inside cells.

Recent studies, however, indicate that another drug, anastrozole, is more effective than tamoxifen and has fewer side effects. Anastrozole reduces estrogen levels in the body by inhibiting production of the hormone, thereby suppressing hormone-sensitive tumor growth. If breast cancer progresses while a patient is on hormonal therapy, fulvestrant, a drug that lowers estrogen receptor levels, may be given.

In this phase III trial, researchers are comparing the effectiveness of anastrozole alone or in combination with fulvestrant as first-line therapy in treating postmenopausal women who have hormone-sensitive, metastatic breast cancer.

"This study will show us whether there is an added benefit to combining fulvestrant with anastrozole as a first-line therapy," said Dr. Mehta. "Furthermore, this type of regimen may ultimately serve as a treatment for earlier breast cancer."

Who Can Join This Trial?

Researchers seek to enroll 690 postmenopausal women with advanced metastatic breast cancer and whose tumors are hormone sensitive. See the full list of eligibility criteria ⁴ for this trial.

Where Is This Trial Taking Place?

Multiple study sites in the United States and Canada are recruiting patients for this trial. See the list of study sites ⁵.

Contact Information

See the list of study contacts ⁵ or call the NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). The call is toll free and completely confidential.

Glossary Terms

An anticancer drug that is used to decrease estrogen production and suppress the growth of tumors that need estrogen to grow. It is a type of nonsteroidal aromatase inhibitor.

A type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions.

Initial treatment used to reduce a cancer. First-line therapy is followed by other treatments, such as chemotherapy, radiation therapy, and hormone therapy to get rid of cancer that remains. Also called induction therapy, primary therapy, and primary treatment.

A drug used to treat certain types of breast cancer in postmenopausal women. It is also being studied in the treatment of other types of cancer. Fulvestrant blocks estrogen activity in the body and is a type of antiestrogen. Also called Faslodex and ICI 182780.

A study to compare the results of people taking a new treatment with the results of people taking the standard treatment (for example, which group has better survival rates or fewer side effects). In most cases, studies move into phase III only after a treatment seems to work in phases I and II. Phase III trials may include hundreds of people.

A drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast) and in women who are at a high risk of developing breast cancer. Tamoxifen is also being studied in the treatment of other types of cancer. It blocks the effects of the hormone estrogen in the breast. Tamoxifen is a type of antiestrogen. Also called tamoxifen citrate.