NHLBI Stops Trial of Estrogen Plus Progestin

"NHLBI Stops Trial of Estrogen Plus Progestin Due to Increased Breast Cancer Risk and Lack of Overall Benefit."

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) has stopped early a major clinical trial of the risks and benefits of combined estrogen and progestin in healthy menopausal women due to an increased risk of invasive breast cancer. The large multi-center trial, a component of the Women's Health Initiative (WHI), also found increases in coronary heart disease, stroke, and pulmonary embolism in study participants on estrogen plus progestin compared to women taking placebo pills. There were noteworthy benefits of estrogen plus progestin, including fewer cases of hip fractures and colon cancer, but on balance the harm was greater than the benefit. The study, which was scheduled to run until 2005, was stopped after an average follow-up of 5.2 years.

The study's Data and Safety Monitoring Board (DSMB), an independent advisory committee charged with reviewing results and ensuring participant safety, recommended at its regularly scheduled meeting on May 31, 2002, that the trial be stopped based on the finding of increased breast cancer risk, supported by the evidence of overall health risks exceeding any benefits.

However, the DSMB has found no indication of increased risk for breast cancer in a parallel WHI study of estrogen only in women who had a hysterectomy before joining the WHI hormone program. Because the balance of risks and benefits of estrogen alone is still uncertain, that study continues unchanged.

The report from the WHI investigators on the estrogen plus progestin study findings will be published in the July 17 issue of, The Journal of the American Medical Association(JAMA); because of the importance of the information, the study is being released early on Tuesday, July 9, as an expedited article on the JAMA Web site.

Following the NHLBI's decision to stop the estrogen plus progestin study, the Institute and the investigators have worked intensively to develop information materials regarding the WHI findings for participants in all WHI-related studies. These materials, as well as a news release and links to the JAMA article and a related editorial, can be found at:

Estrogen Plus Progestin Study Stopped Due to Increased Breast Cancer Risk, Lack of Overall Benefit

Source: NHLBI Stops Trial of Estrogen Plus Progestin Due to Increased Breast Cancer Risk, Lack of Overall Benefit - National Institutes of Health, July 9, 2002.