The landmark BCPT and the follow-up STAR (Study of Tamoxifen against Raloxifene) trials, 2 separate randomized controlled studies, enrolled a total of >32 000 women at risk for breast cancer (2, 8).
Together, the BCPT and STAR trials demonstrated that safety can be improved in iterative generations of agents and trials.
I have to ask, why aren't the results of the BCPT
and STAR trials more vigorously applied in clinical practice?
In the aforementioned BCPT, launched in 1992, 13,388 women 35 years and older who were deemed to be at high risk of developing breast cancer were enrolled at numerous sites throughout the United States and Canada.
The BCPT was stopped 14 months before planned because the Data and Safety Monitoring Board felt it was unethical to continue to allow one half of such high-risk participants to take placebo in light of the dramatic reduction in both invasive and noninvasive breast cancer among women who took tamoxifen.
In the BCPT, more than 13,000 women were randomly assigned to take either placebo or 20 mg of tamoxifen per day for approximately 4 years.
Among patients who took tamoxifen in the BCPT, there were 33 cases of endometrial cancer versus 14 cases in those who took placebo ("Breast Cancer," 1998).
She reported on 13,388 women at high risk for developing breast cancer who were randomized to tamoxifen or placebo in the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial (NSABP BCPT
The recently completed US Breast Cancer Prevention Trial (BCPT
) showed that tamoxifen reduced the risk of developing breast cancer by 45% in women at high risk (number needed to treat = 94).
Interim results of the BCPT
released in April showed 45% fewer cases of breast cancer among women who took tamoxifen than among those who took placebo.