News of two new studies linking cancer to hormone-replacement therapy has me wondering (once again) how we are supposed to trust doctors when the medical information about women's health keeps changing.
Extolled as a preventive measure against heart disease, osteoporosis and the ravages of menopause, hormone replacement therapy was prescribed to millions of women in the 1990s. When a 2002 study came out suggesting that HRT increased women's risk of breast cancer, stroke and other serious conditions, many women stopped using the drugs. (The study also concluded that women on this particular HRT had an elevated risk of heart disease.) Now a new data analysis published in the New England Journal of Medicine suggests that the 8.6 percent drop in breast cancer between 2001 and 2004 correlates closely with the decline in HRT use. Most of the drop in cancers came in 2003 -- just after the announcement about HRT cancer risk -- with rates leveling in 2004.
Another study from the Cancer Research U.K. Epidemiology Unit in Oxford and published in the Lancet medical journal, found women taking HRT had a 20 percent higher chance of dying from ovarian cancer. The researchers estimated that this accounted for about 1,000 more deaths in Britain between 1991 and 2005. Although 1,000 deaths sounds like 1,000 deaths too many, the additional risk is considered slight: Instead of 2.2 cases of ovarian cancer for every 1,000 women, HRT use raises the rates to 2.6 in every 1,000 women.
But taken as a whole, the higher risk of breast, ovarian and endometrial cancer is more substantial, with the incidence of these cancers 63 percent higher among HRT users than those who never used the hormones. What's most troubling about these findings is how hard the medical establishment pushed for women to take these drugs. I recall my mother being strong-armed into going on HRT well after she'd passed through menopause. It would keep her young! With our history of trying to keep women forever fertile and forever in a good mood, I can't help thinking that the ubiquitous push for HRT was part and parcel of a wish to fix aging women. For this aging broad, the HRT roller coaster is another cautionary tale to think twice when medicine comes up with cures for the natural aging of the female body.
Downstream postscript: The link between HRT and cancers has been explained as a result of the estrogen in HRT feeding certain kinds of cancers. In a study, reported on today by Scientific American, one can see how women simply stopping HRT won't necessarily eradicate the risk. Researchers tested fresh fish from a number of sources around Pittsburgh (as well as store-bought controls) and found that many contain enough chemicals that mimic estrogen to cause breast cancer to grow. As for the source of these chemicals: Since the most polluted fish came from near sewer runoff rather than heavy industry, the researchers guessed that HRT, birth control pills and other refuse are getting into our water system and changing the fish we eat.