Warnings Page: Estrogen/Progestin Study,
Nolvadex and Zonegran Updates

Study of Estrogen Plus Progestin Halted Due to Increased Risk of Breast Cancer

WASHINGTON, D.C.-The National Heart, Lung and Blood Institute (NHLBI) decided to end a clinical trial focused on the overall benefits and risks of estrogen plus progestin after finding a significant increase in the risk of breast cancer, heart attack and pulmonary embolism among those taking the treatment.

The estrogen plus progestin trial, a component of the Women's Health Initiative (WHI), consisted of 16,608 women ages 50 to 79. The study was designed to evaluate the effects of estrogen plus progestin therapy in the prevention of heart …