STAR Trial Update
By Jennifer Bucholtz, MS, CRNP, OCN

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The STAR (Study of Tamoxifen and Raloxifene) Trial officially opened for participation on July 1, 1999. Over 1,500 women from the Unites States, Canada and Puerto Rico have already entered this Breast Cancer Prevention Study, sponsored by the National Surgical Adjuvant Breast and Bowel Project (NSABP) and the National Cancer Institute (NCI). Over 500 sites are participating in this important study.

STAR is one of the largest breast cancer prevention trials ever to be undertaken. It is the first research study to compare a drug proven to reduce the risk of developing breast cancer with another drug that has the potential to reduce the incidence of breast cancer. The drug Tamoxifen was proven in the first Breast Cancer Prevention Trial sponsored by NSABP to reduce breast cancer incidence by 49% in women at an increased risk compared to a placebo. In October 1998, the Food and Drug Administration (FDA) approved the use of Tamoxifen for the reduction of breast cancer incidence in women at increased risk.

Raloxifene was approved by the FDA for the prevention of osteoporosis (thinning of the bones) in postmenopausal women. A trial that studied the effectiveness of the drug in preventing osteoporosis (Multiple Outcomes of Raloxifene Evaluation or MORE Trial) found that it also reduced the incidence of breast cancer. STAR randomizes women to either Tamoxifen or Raloxifene for a 5-year period. The study will compare their effectiveness in reducing breast cancer incidence and their side effects.

Women eligible for STAR must be 35 years of age or older, postmenopausal and have an increased risk for breast cancer. Increased risk is determined by many factors including age, age at first menstrual period, age at first live birth, family history of breast cancer, personal history of breast biopsies and race. Women with certain medical conditions are not eligible for STAR. These conditions include a history of breast cancer, blood clots, stroke, and certain types of heartbeat irregularities. Women with uncontrolled diabetes or uncontrolled hypertension also cannot participate.

Both Tamoxifen and Raloxifene have known side effects. The most common side effects are hot flashes and vaginal discharge. Rare but more serious side effects include blood clots in the leg, lung or possibly a stroke. Endometrial cancer can occur in a very small percentage of women who take Tamoxifen. Women who have had a hysterectomy are not at risk for endometrial cancer. Since Raloxifene has not been studied as long as Tamoxifen, not as much is known about its long-term side effects.

Postmenopausal women living in the United States or Puerto Rico who are interested in participating in STAR can call the National Cancer Institute's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). In Canada, women can call the Canadian Cancer Society at 1-888-939-3333.

Jennifer Bucholtz is Program Coordinator for the STAR Trial at Johns Hopkins. (410) 614-STAR (410-614-7827)