Proponents of HRT constantly attempt to make light of the proven breast and endometrial cancer risks of HRT. A perfect example of this is King's College Hospital John Studd's view that although the breast cancer risk of HRT admittedly is increased, since several studies have shown that fewer women die from HRT caused disease than ordinarily, this isn't such a big deal. "There is not enough information to suggest that breast cancer risk is a valid reason to hold estrogen therapy," he says (J of Royal Society of Medicine, July 1992).
Actually, almost every study to date about HRT demonstrates a significant cancer risk; the only thing disputed on is exactly how substantial this risk is.An analysis of 37 studies of breast cancer risk concluded that long term estrogen use increases breast cancer risk by 60 per cent (Ob and Gyne, February 1992).
A Swedish prospective study of 23,000 women using HRT over nearly six years found a 80 per cent increase in risk in women using estrogen alone. However, the highest risk was the continuous combination estrogen progestogen drug, which showed that risk more than quadrupled over six years. (New Eng J of Med, 3 August 1989).
An analysis of 16 studies of HRT concluded that after 15 years, breast cancer risk increased by 30 per cent in users of estrogen alone but more than doubled in those using the combination drug. This risk increased with every year of use. Based on 1987 use, this would translate into 4708 new cases of breast cancer and 1468 deaths from estrogen among American women every year (J of the Amer Med Assoc, 17 April 1991).
As for endometrial cancer risk, estrogen alone more than trebles the risk, but progestogen only brings the risk down to and 80 per cent increase, a risk that continues for five years after you stop the drug. (Ob and Gyne, February 1993).
The use of opposed HRT preparations lowers your risk of contracting endometrial cancer over the whopping increase with estrogen preparations alone, which can increase your chances twentyfold. But the opposed drug still increases your endometrial cancer risk up to a third over those who don't take HRT. (Annals of Inter Med, 1992;177, 12: 1016-37).