The Study of Tamoxifen and Raloxifene or STAR is a breast cancer prevention clinical trial designed to determine whether the osteoporosis prevention and treatment drug raloxifene (Evista) is as effective as tamoxifen (Nolvadex) in reducing breast cancer risk. The trial began enrolling participants in July 1999 and will continue enrollment until 22,000 postmenopausal women are in the study.

• Since STAR began, 96,244 women have gone through the risk assessment process to determine their eligibility for the trial. Of these women, 54,890 were eligible for the trial because of their increased risk of developing breast cancer. Of those risk-eligible women, 11,307 have chosen to participate. STAR will ultimately include 22,000 postmenopausal women at increased risk of breast cancer.

• Of the 11,307 women who have joined STAR, 1,284 were from the placebo group of the Breast Cancer Prevention Trial (the study compared tamoxifen to a placebo).

• The estimated breast cancer risk of women joining STAR has been substantially above the minimum 1.7 percent risk of developing the disease within the next five years. (See Background for more information.)

Five Year Breast Cancer Risk//Percent of women in STAR

1.7- 2.0 percent// 10.8 percent

2.0-2.9 percent// 30.5 percent

3.0-4.9 percent// 31.5 percent

Greater than 5.0 percent// 27.2 percent

• Women joining STAR must be postmenopausal and at least 35 years of age. The ages of women joining STAR:

Age// Percent of women in STAR

35-49// 9.5 percent

50-59// 50.2 percent

60+// 40.3 percent

• 8.3 percent of the women who have joined STAR report a previous diagnosis of lobular carcinoma in situ (LCIS), a condition that is not cancer, but which indicates an increased chance of developing invasive breast cancer.

• More than half of the women who have joined STAR have had a hysterectomy prior to enrolling (52.1 percent). Women who have had a hysterectomy are not at risk for endometrial cancer; tamoxifen can raise a woman's chance of developing that disease (see Background section below for more information).

• Number of women who joined STAR by U.S. state and Canadian province:

U.S. States (and Puerto Rico)

Alabama 76

Alaska 11

Arizona 133

Arkansas 37

California 794

Colorado 200

Connecticut 189

Delaware 51

District of Columbia 11

Florida 316

Georgia 120

Hawaii 93

Idaho 32

Illinois 636

Indiana 224

Iowa 226

Kansas 210

Kentucky 114

Louisiana 107

Maine 52

Maryland 174

Massachusetts 276

Michigan 536

Minnesota 272

Mississippi 68

Missouri 410

Montana 61

Nebraska 86

Nevada 79

New Hampshire 44

New Jersey 198

New Mexico 72

New York 474

North Carolina 349

North Dakota 66

Ohio 465

Oklahoma 151

Oregon 120

Pennsylvania 702

Puerto Rico 43

Rhode Island 17

South Carolina 239

South Dakota 69

Tennessee 183

Texas 833

Utah 12

Vermont 64

Virginia 121

Washington 271

West Virginia 52

Wisconsin 250

Wyoming 8

Canadian Provinces

Alberta 97

British Columbia 61

Manitoba 88

New Brunswick 1

Nova Scotia 1

Ontario 187

Quebec 458

Saskatchewan 17

• Postmenopausal women of all races and ethnic backgrounds are encouraged to participate in STAR, and about 6 percent of the women in STAR are from minority groups. A total of 15,022 women from minority groups have gone through the risk assessment process; 3,781 had an increased risk of breast cancer that would qualify them for the study; and 636 have joined.

• 8,835 African-American women have gone through the risk assessment process, 1,582 were risk eligible, and 242 joined STAR. About 2.1 percent of STAR participants are African-American.

• 3,369 Hispanic/Latina women have gone through the risk assessment process, 861 were risk eligible, and 185 joined STAR. About 1.6 percent of the women on STAR are Hispanic/Latina.

• 2,818 women who defined themselves as representing another minority population, such as Native American or Asian American, have gone through the risk assessment process, 1,338 were risk eligible, and 209 joined STAR. About 1.8 percent of the women on STAR are ethnic minorities other than African American or Hispanic/Latina.

• In only the first two years of STAR, 30 percent more minority women have joined the trial as had joined the predecessor study to STAR over five years. That study, the Breast Cancer Prevention Trial had a total of 8,525 minority women go through the risk assessment process, 2,979 were risk-eligible, and 486 joined this 13,000-woman trial.

• More than 500 centers across the United States, Puerto Rico, and Canada are enrolling participants in STAR. STAR is conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP) and is supported by the U.S. National Cancer Institute (NCI).

• Women who participate in STAR have an increased risk of developing breast cancer as determined by their age, family history of breast cancer, personal medical history, age at first menstrual period, and age at first live birth. They also go through a process known as informed consent, during which they learn about the potential benefits and risks of tamoxifen and raloxifene before deciding whether to participate in STAR.

• Women can join STAR if they have an increased risk of developing breast cancer equivalent to the risk of an average 60-year-old woman. These women have a 1.7 percent risk of developing breast cancer within five years, meaning that about 17 of 1,000 would be expected to develop breast cancer within five years.

• Tamoxifen and raloxifene may also increase a woman's chances of developing several rare, but potentially life-threatening health problems: deep vein thrombosis (blood clot in a large vein), pulmonary embolism (blood clot in the lung), endometrial cancer (cancer of the lining of the uterus), and possibly stroke. Tamoxifen increases a woman's risk of endometrial cancer at a rate similar to that of estrogen replacement therapy without progesterone. In ongoing studies, raloxifene has not been associated with an increased risk of endometrial cancer. STAR will help further define the risks and benefits of tamoxifen and raloxifene therapy.

• Once a woman decides to participate, she is randomly assigned to receive either 20 mg tamoxifen or 60 mg raloxifene daily for five years and has regular follow-up examinations, including mammograms and gynecologic exams. Neither the woman nor her doctor will know which drug she is taking.

• The maker of tamoxifen, AstraZeneca Pharmaceuticals, Wilmington, Del., and the maker of raloxifene, Eli Lilly and Company, Indianapolis, Ind., are providing their drugs and matching placebos for the trial without charge.

• Tamoxifen was proven in the 13,000-woman Breast Cancer Prevention Trial to reduce breast cancer incidence by 49 percent in women at increased risk of the disease. The trial also showed that tamoxifen works like estrogen to preserve bone strength, decreasing fractures of the hip, wrist, and spine in the women who took the drug. In October 1998, the FDA approved the use of tamoxifen to reduce the incidence of breast cancer in women at increased risk of the disease. Tamoxifen has been approved by the FDA to treat women with breast cancer for more than 20 years and has been in clinical trials for about 30 years.

• In a large study using raloxifene, that included postmenopausal women with osteoporosis, the number of cases of breast cancer in women who took the drug was reduced compared to women who took a placebo. Raloxifene was approved by the FDA to prevent osteoporosis in postmenopausal women in December 1997, and to treat osteoporosis in postmenopausal women in September 1999. It has been under study for about eight years.

• Postmenopausal women in the United States and Puerto Rico who are interested in participating in STAR can call the NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) for information in English or Spanish. The number for callers with TTY equipment is 1-800-332-8615.

• Postmenopausal women in Canada who are interested in participating in STAR can call the Canadian Cancer Society's Cancer Information Service at 1-888-939-3333 for information in English or French.

• For more information via the Internet, visit NSABP's Web site at http://www.nsabp.pitt.edu or NCI's STAR Web site at http://cancer.gov/star

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