A female friend of a friend started on hormone replacement therapy (to treat quite severe early postmenopausal symptoms, and on the advice of her GP to reduce the risk of osteoporosis). The symptoms have all but been relieved (although it’s difficult to separate out the effects of the HRT hormones themselves from the phytoestrogens she imbibes from soy milk and other related foods).
Either way, the recent Lancet paper, which received lots of media attention, got her all hot and bothered. She’s an earlier finisher, and is likely to be on HRT for ten years or so, is that going to mean she will get ovarian cancer. The tabloid hype surrounding the paper would seem to suggest so, but as with all statistical health studies that get pounced on by the media it’s worth taking a closer look.
Interpreting the results and scaling up to whole number women, as opposed to fractional women, over 5 years, ovarian cancer incidence for those who have never used HRT was 26 per 10,000. It was 30 per 10,000 for HRT users.
The researchers conclude that, “Women who use HRT are at an increased risk of ovarian cancer. Since 1991, use of previous has resulted in 72 additional cancers per year and 55 additional deaths in the UK.” Their results are based on the million women study, in which 500,000 were HRT and 500,000 were not.
Of course, ovarian cancer is the fourth most common cancer in women in the UK, with some 6700 developing the malignancy and 4600 dying from it every year. The high incidence of deaths is presumably down to the hidden nature of this form of cancer, which is often not detected until it has reached a lethal stage. 72 additional cancers and 55 additional deaths is a significant but not an enormous increase.
The researchers also add that, “In total, ovarian, endometrial, and breast cancer account for 39% of all cancers registered in women in the UK.1 and 2 The total incidence of these three cancers in the study population is 63% higher in current users of HRT than in never users (31 vs 19 per 1000 over 5 years, figure 6). Thus, when ovarian, endometrial, and breast cancer are taken together, use of HRT results in a material increase in the incidence of these common cancers.”
But, these are risk factors and there is simply no way of making any kind of prediction, with current medical knowledge, of whether or not a particular woman on HRT will suffer any form of cancer because of the HRT drugs she is taking. The researchers mention that as HRT use has declined in the US (partly because of the negative publicity it receives), we are also now seeing falling breast cancer rates there.
According to the author of the paper, Valerie Beral of Cancer Research UK, “It is a small but significant risk. It’s more an issue for women to think about how much they want to take HRT to relieve their symptoms against the known risks.”
However, it’s not all about hot sweats and sexual libido, as life expectancy rises in general and the aspirations of older people for a happy and active retirement rises concomitantly, it will be interesting to see whether a few less cancers will be offset by a rise in osteoporosis incidence and the other “side-effects” of the menopause (particularly early onset menopause).
An elderly neighbour of mine has been in and out of hospital with bone density issues and fractures repeatedly and at one point suffered a potentially lethal hospital-acquired MRSA (multiple-resistant Staphylococcus aureus) infection as a result. To my mind, she would most likely not have suffered in this way had she taken HRT during the early menopause. But, equally there is also the thought that had she died of cancer sooner than the osteoporosis kicked in, she would not have suffered bone density problems later in life either.
For every statistic, a counter statistic can be found and when the overall risks are very small it is difficult for the public, the media, and even the medical scientists to know for sure which way to push the agenda.