Preliminary results of the STAR ( Study of Tamoxifen and Raloxifene ) trial showed that the drug Raloxifene ( Evista ), currently used to prevent and treat osteoporosis in postmenopausal women, works as well as Tamoxifen in reducing breast cancer risk for postmenopausal women at increased risk of the disease.
In STAR trial, both drugs reduced the risk of developing invasive breast cancer by about 50 percent.

STAR enrolled 19,747 women. The data analysis is based on the 19,471 women for whom complete study information was available.

The numbers of invasive breast cancers in both groups of women were statistically equivalent. Among the 9,745 women in the Raloxifene group, 167 developed invasive breast cancer, compared to 163 of 9,726 women in the Tamoxifen group.

More than half of the women who joined STAR had had a hysterectomy and, therefore, were not at risk of uterine cancer. For those women with a uterus, 36 of 4,732 who were assigned to take Tamoxifen developed uterine cancers ( mainly endometrial cancer ) compared to 23 of 4,712 women who were assigned to take Raloxifene.

In STAR, women in the Raloxifene group had 29 percent fewer deep vein thromboses (blood clots in a major vein) and pulmonary embolisms than women in the Tamoxifen group. Specifically, 87 of 9,726 women in the Tamoxifen group had a deep vein thrombosis compared to 65 of 9,745 women taking Raloxifene. In addition, 54 of 9,726 women taking Tamoxifen developed pulmonary embolisms compared to 35 of 9,745 women taking Raloxifene.

The number of strokes occurring in both groups of women was statistically equivalent: 53 of 9,726 women in the Tamoxifen group and 51 of 9,745 women in the Raloxifene group had a stroke during the trial. There was no difference in deaths from strokes: 6 of 9,726 women in the Tamoxifen group and 4 of 9,745 women in the Raloxifene group died from this event.
Women at increased risk of stroke ( those with uncontrolled hypertension or uncontrolled diabetes, or a history of stroke, transient ischemic attack, or atrial fibrillation ) were not eligible to participate in STAR.

While Tamoxifen has been shown to reduce, by half, the incidence of lobular carcinoma in situ ( LCIS ) and ductal carcinoma in situ ( DCIS ), Raloxifene did not have an effect on these diagnoses.
Of the 9,726 women taking Tamoxifen, 57 developed LCIS or DCIS, compared to 81 of 9,745 taking Raloxifene. This result confirms data reported in 2004 in a large study of Raloxifene, the Continued Outcomes Relevant to Evista ( CORE Trial ).

Source: National Institutes of Health, 2006


XagenaMedicine2006