A new British review has concluded that a woman taking HRT is more likely to contract a life-threatening disease than be protected against one.
The analysis of four major studies, involving 20,000 postmenopausal women taking HRT for five years, found that such women in their 50s had a higher risk of breast cancer, while those in their 60s had greater chances of stroke or pulmonary embolism (blood clots in the lung).
The researchers estimated that, over five years, there would be six extra cases of breast cancer, stroke or pulmonary embolism for every 1000 healthy women aged 50-59 taking HRT. The number doubles to 12 per 1000 for users aged 60-69.
Reductions in the number of expected cases of bowel cancer or hip fracture were low at 1.7 and 5.5, respectively, per 1000 HRT users in the two age groups (Lancet, 2002; 360: 942-4).
These results support the Women's Health Initiative (WHI) study of healthy women taking HRT, halted earlier this year because of health risks with HRT, and show no changes in the risks of endometrial cancer or coronary heart disease.
In another study, postmenopausal HRT raised levels of C-reactive protein (CRP), one of several inflammatory markers of increased cardiovascular risk (JAMA, 2002; 288: 980-7). Using data from the WHI, it was noted that women with high levels of CRP were more likely to suffer a heart attack or fatal heart failure within three years of starting HRT.
Among women with high CRP levels, HRT use increased CRP levels by 55 per cent vs women with normal CRP levels. These latter women had CRP levels that were raised 70 per cent vs healthy women not taking HRT.
These new findings mean that doctors can no longer safely recommend HRT for every menopausal ill (JAMA, 2002; 288: 882-4).