HRT Treatment – Cancer and Other Risks
Menopause is the complete disappearance of a woman's monthly cycles for 6 to 12 months and is caused by declining production of estrogen and progesterone hormones by the ovaries. When the ovaries are removed, this is referred to as "surgical menopause." Hormone-replacement therapy (HRT) provides a postmenopausal woman with the absent hormone(s), although not in the amounts once produced by the ovaries.
About 10 million women have been taking HRT, making these drugs among the most prescribed in the United States. However, new data call for a major reevaluation of this situation. After an average of 5.2 years of follow-up on women on HRT, the data showed increases in the risk of breast cancer, heart disease, and stroke, but decreased risk of colon and rectal cancer, uterine cancer, hip fracture, and death from other causes. The only statistically significant findings, however, were the reduced risk of fracture and colon and rectal cancer. The researchers concluded that combined estrogen-progestin HRT (a) should not be used on a population-wide basis for postmenopausal women and (b) should not be started or continued for the purpose of preventing coronary heart disease in apparently healthy women. They also concluded that the risks should be considered when choosing among the drugs available to prevent osteoporosis.
What should women do? To begin with, they should realize that, as with most scientific research, there are problems with the WHI data, which allow them to be interpreted in various ways. The average age at which women in this study began taking HRT, for example, was 63.3 years, far beyond the age at which women typically begin hormone replacement. In addition, because the study lasted only 5.2 years, almost all of the extra breast cancers would have been pre-existing based on what is known about the biology of breast cancer. It has also been shown that women diagnosed with breast cancer while taking HRT have a better prognosis than those not taking HRT at the time of diagnosis. Another serious problem with the study is that the rates at which women chose to either begin or stop taking estrogen on their own was high and exceeded the design projections of the study. Many other issues have also been raised in scores of letters to the editors and additional articles in the medical literature. While this may seem confusing to consumers, this is how real medical science works.
The most important thing for women who may be candidates for HRT to keep in mind is that the goal of good medical care is to live as long and healthfully as possible and not just to avoid a particular disease. In addition, estrogen and progestins are normal body hormones that are known to be important to the function of many body tissues in women but which also affect the risk of disease. For example, HRT reduces the risk of colon and rectal cancer, a more deadly form of cancer than breast cancer, although breast cancer is more common. Meanwhile, the risk of breast cancer has been known for many years to be most increased by an early onset of menstrual periods, a late age of menopause, late or no childbearing, and absence of breastfeeding. Women at an increased risk of breast cancer can even reduce their risk by undergoing removal of their ovaries. The same is likely true for other women, but it seems unlikely that many would choose to undergo castration simply to reduce their risk of breast cancer. In the end, it should be remembered that life is full of risks and the challenge is to manage risk since it can rarely be eliminated.
Although the report of results from the HRT arm of the WHI study raises legitimate concerns, it did not show excess deaths among users of the combined HRT treatment and does not apply to all clinical situations. Meanwhile, cardiovascular disease remains the leading cause of death in women as well as in men and the most important risk factors for cardiovascular disease have little to do with hormonal status. Therefore, with respect to HRT, women should review their individual circumstances with a knowledgeable physician to determine whether HRT makes sense for them as part of an overall strategy to optimize their health and reduce the risk of health problems and premature death.