Hormone replacement therapy (HRT) has many proven benefits for women in the menopausal transition. However, care must still be taken to ensure that HRT is the right treatment for each individual patient. Presenting at EMAS 2019, Dr. Amos Pines and Dr. Margeret Rees sought to clarify whether HRT is appropriate for survivors of myocardial infarction, stroke and cancer.
Myocardial infarction and stroke survivors
In 1998, published guidelines stated that there was a ‘clear cut protective effect of estrogen in healthy as well as in women with know cardiovascular disease.  Dr. Pines explained that now this thinking has very much changed.
Currently guidelines prohibit HRT in the context of secondary prevention of cardiovascular disease (CVD), post myocardial infarction and post-stroke symptomatic patients. However, this recommendation is based on old studies. New research instead suggests that there are less adverse outcomes or even neutrality if low-dose or transdermal preparations are prescribed.
One recent study suggests that use of transdermal estrogen is less likely to produce thrombotic risk and perhaps also the risk of stoke and coronary artery disease. 
Another suggested that discontinuation of HRT in the first 30-360 days after myocardial infarction was not associated in any adverse cardiovascular outcomes compared to those that continued treatment. For those women who are already on HRT, there may be the potential to continue treatment even after myocardial infarction. 
More large scale longitudinal studies are needed to confirm the true impact of HRT for myocardial infarction and stroke survivors.
Whether HRT can be used for cancer survivors depends on many factors, Dr. Rees explained.
Estrogen dependence of the tumour
Age/ premature menopause
Comorbidities e.g. cardiac disease and concomitant medications such as tamoxifen or aromatase inhibitors
For early stage endometrial cancer, there remains insufficient high-quality evidence to inform whether HRT can be used after treatment, however the available evidence does not suggest significant harm. For FIGO stage II or above endometrial cancer, there is even less information available. Dr. Rees suggested that HRT treatment should be individualised, taking into account the woman’s symptoms and preferences.
Uterine sarcomas are estrogen dependant and HRT should not be prescribed. Epithelial Ovarian cancer is a different story. Studies of estrogen replacement do not show an adverse effect on survival. For Endometrioid ovarian cancers, while they are estrogen dependant, again no adverse effect is seen with HRT. Dr. Rees advised caution for women with stage 3 endometrioid adenocarcinomas, where commonly residual and potentially hormone responsive disease after surgery is present.
It is important that our understanding of HRT and cancer continues to be adapted and developed based on the best current data, to ensure women receive the best possible treatment.
 Elizabeth Barrett-Connor Deborah Grady. HORMONE REPLACEMENT THERAPY, HEART DISEASE, AND OTHER CONSIDERATIONS. Annual Review of Public Health. 1998: 19(1) 55-72
 Cobin RH, Goodman NF; AACE Reproductive Endocrinology Scientific Committee. American Association of Clinical Endocrinologists and American College of Endocrinology position statement on menopause—2017 update. Endocr Pract. 2017;23(7):869-880.
 Jakob Raunsø, Christian Selmer, Jonas Bjerring Olesen et al.Increased short-term risk of thrombo-embolism or death after interruption of warfarin treatment in patients with atrial fibrillation, European Heart Journal. 2012: 33 (15) 1886–1892,