Low doses of Wyeth's Prempro, a combination of both kinds of female hormones, progesterones and estrogen, have been proven to relieve hot flashes, night sweats, and vaginal symptoms of menopause. But does Hormone Replacement Therapy cause breast cancer? This is a controversial question. The well-regarded Toronto Breast Cancer Study reported that women who received HRT for less than 15 years are not at increased risk of breast cancer. On the other hand a New Zealand study suggested that women taking may be at higher risk for breast cancer during the first 5 years, but therapy for more than 5 years confers no increased risk of breast cancer. Then the Women's Health Initiative (WHI) study found an increased risk of heart attacks, stroke, breast cancer, blood clots, and pulmonary emboli (blood clots in the lungs) in postmenopausal women (50-79 years old) who took progesterone in combination with estrogens for 5 years. The WHI study received national notoriety because it was discontinued early because of its finding that HRT correlated to an increased risk of invasive breast cancer and other health problems. The study found that among those taking Prempro-like hormone replacement therapy, the rate of breast cancer was 38 per 10,000 women per year. Among those taking placebo, the rate was 30 per 10,000 women per year.
This study has now cost Wyeth, the producer of Prempro, over $9 million. In Singleton v. Wyeth, a Philadelphia jury decided that Wyeth should pay $6 million in punitive damages and $3.45 million in compensatory damages for failing to adequately warn a patient and her doctor about the increased risk of breast cancer. Here's the law.com summary of the case.
Wyeth's counsel emphasized that the warning was reasonable, and that there was scientific disagreement about the cancer risks. But the jury took just seven minutes to reach a unanimous verdict on the punitives.
Prempro is still widely marketed and used. The current "black box" warning states, "Using estrogens, with or without progestins, may increase your chance of getting heart attacks, strokes, breast cancer, and blood clots." That warning is good enough for the FDA. Should it be good enough for a jury?