Benefits and harms of combined MHT
In postmenopausal individuals, combined MHT reduces the risk of:
- fractures of all types (44 fewer per 10 000 person years)
- hip fractures (6 fewer per 10 000 person years)
- diabetes mellitus (14 fewer per 10 000 person years)
- colorectal cancer (6 fewer per 10 000 person years)
- self-reported vasomotor symptoms (2816 fewer per 10 000 person years)1.
In postmenopausal individuals, combined MHT increases the risk of:
- invasive breast cancer (9 additional cases per 10 000 person years)2
- stroke (9 additional cases per 10 000 person years)
- venous thromboembolism (deep vein thrombosis [DVT] or pulmonary embolism [PE]) (21 additional cases per 10 000 person years)
- gallbladder disease (21 additional cases per 10 000 person years)
- dementia (22 additional cases per 10 000 person years)3
- self-reported urinary incontinence (876 additional cases per 10 000 person years)
- coronary heart disease (8 additional cases per 10 000 person years).
The increased risk of stroke and coronary heart disease may only apply to people 60 years and older; younger people may derive a mortality benefit of 6 per 10 000 women years, according to a Cochrane review4.
Combined MHT has no effect on risk of endometrial cancer, lung cancer, ovarian cancer or cervical cancer.
1 Manson JE, Chlebowski RT, Stefanick ML, Aragaki AK, Rossouw JE, Prentice RL, et al. Menopausal hormone therapy and health outcomes during the intervention and extended poststopping phases of the Women's Health Initiative randomized trials. JAMA 2013;310(13):1353-68. [URL]Return
2 Prospective observational studies of combined oral and transdermal preparations suggest the increase in risk of invasive cancer might be greater than this figure. Risk was observed to increase with longer duration of combined MHT use, and to persist up to 10 years after MHT was stopped. Estimates of risk are greater for continuous combined MHT compared to cyclical combined MHT and estrogen-only MHT.Return