Tamoxifen trial resumes.

On Nov.9, the University of Pittsburgh resumed its enrollment of healthy women into the Breast Cancer Prevention Trial--the first of some 300 participating centers to do so. Directed by the National Surgical Adjuvant Breast and Bowel Project (NSABP), this study began in early 1992. But recruitment of new volunteers to it and all other NSABP studies came to an abrupt halt in April, pending a federal investigation of data-handling irregularities by NSABP, a research cooperative (SN: 4/30/94, p.282).

At that time, the prevention trial had enrolled only about two-thirds of the 16,000 women needed to yield statistically reliable data. Throughout the 7-month reassessment period, those already taking part in the trial continued to receive either tamoxifen -- the world's top-selling cancer medication -- or an inactive powder shaped into identical-looking pills.

Responding to concerns of the National Cancer Institute (NCI), which funds the NSABP studies, "a corrective plan of action was formulated to address data monitoring and quality assurance," according to a statement last week by the University of Pittsburgh, where NSABP is headquartered. It added that "new administrative procedures have been implemented, and ongoing reviews of participating sites are being conducted."

During the recruitment hiatus, several advisory boards reporting to NCI and the Food and Drug Administration reevaluated the prevention trial's design. Each concluded that the trial was important and should continue, despite a series of reports earlier this year indicating that women who take tamoxifen face a significantly elevated risk of adverse endometrial changes, including life-threatening malignancies of the uterus (SN: 6/4/94, p.356).

Because of this risk, new recruits must agree to a biopsy of endometrial tissue before receiving the drug and will be encouraged to get annual followup biopsies--all at the study's expense. Current participants will be offered access to the same NSABP-funded biopsies.