Two new studies may assist doctors in understanding the benefits and risks of using hormone replacement therapy (HRT) drugs, such as Prempro and Premarin.
In one study, researchers found that the breast cancer risks linked to hormone replacement therapy can vary depending on the weight of the woman, and in another study, researchers determined that HRTs should not be used as a preventative measure against heart disease and dementia.
The studies come after years of litigation involving hormone replacement therapy, which largely ended last year after Pfizer agreed to pay $1.2 billion to settle thousands of Prempro breast cancer lawsuits. The complaints alleged that the drug maker failed to adequately research the side effects of hormone therapy or warn about the risk of side effects women may face.
In the breast cancer study, conducted by researchers from Chicago and published September 3 in the Journal of the National Cancer Institute (JNCI), researchers found that women who were of normal or low weight had the highest risk of breast cancer. While there appeared to be no increased risk of HRT breast cancer for women who were overweight, obese and had less-dense breasts. The researchers also found that white, Asian, and Hispanic women faced an increased risk of breast cancer when taking HRT drugs, but African American women did not.
The study involved the analysis of more than 1.6 million screening mammograms with 9,300 breast cancer cases in postmenopausal women ages 45 and older. The data was collected from the Breast Cancer Surveillance Consortium.
The researchers for the JNCI study concluded that the risk stratification could help doctors decide when and if HRT therapy was the correct course of action.
Risks Too High to Prevent Heart Disease, Dementia
Researchers from Harvard and the Boston area determined that using HRT drugs to try to prevent heart disease and dementia was not the correct course of action. In a study published in the Journal of the American Medical Association (JAMA) on October 2, they found that while using HRTs to treat some symptoms of these ailments appeared effective, the risks and benefits of HRTs was too complex to determine if any benefits were worth the risks of using them as a prophylactic.
These researchers looked at data on more than 27,000 women between the ages of 50 and 79. They gave Premarin and medroxyprogesterone acetate (MPA) to women with an intact uterus and just Premarin to women who had undergone a hysterectomy. Some they gave a placebo.
That study found that during the trial HRT use accounted for six more women getting heart disease out of every 10,000 each year. For those given Premarin alone, the risk of stroke increased as well, with 11 additional women per every 10,000 women per year having a stroke.
However, the risk of heart disease appeared to drop during follow-up investigations, and the women taking Premarin alone had less of a chance of breast cancer.
Premarin is one of three HRT drugs, which also includes Prempro and Provera, that have been linked to concerns over an increased risk of breast cancer.
About 10,000 HRT breast cancern lawsuits have been filed by consumers throughout the United States, raising similar allegations over the side effects of Prempro, Provera and Premarin, which are used to artificially boost hormone levels in women undergoing menopause due to surgery or in postmenopausal women.
In 2002, a study by the Women’s Health Initiative first warned of the risk of breast cancer from hormone replacement therapy, sparking the widespread litigation.