Hormone replacement therapy is a treatment given to women experiencing menopause, as well as those who are transitioning form male to female or female to male. HRT specifically for menopause may also be referred to as menopausal hormone therapy (MHT), postmenopausal hormone therapy (PHT), or postmenopausal hormone (PMH). It is often used to treat symptoms of menopause such as hot flashes. However, some recent studies showed that HRT can possibly increase the risk of cancer.
Does hormone replacement therapy cause cancer?
Different types of hormone therapy might have different effects. Estrogen-progestin therapy (EPT) can increase the risk for certain cancers such as breast cancer. A WHI study found that taking EPT can be linked to a higher likelihood of breast cancer. Your risk increases the longer that you take EPT. The good news is that the risk returns to normal three years after you stop taking them. Another study showed that EPT is linked to an increase in breast density which makes it harder to see signs of breast cancer on a mammogram.
Ovarian cancer is less common which makes it harder to study. The risk for ovarian cancer is still low even when certain hormone therapies increase the risk. A recent analysis compared over 50 studies and found that adult women who took estrogen and progestin did have a greater risk of developing ovarian cancer. The risk decreases when you stop taking the hormone therapy.
The results from WHI studies were inconclusive. Women using EPT therapy were less likely to get colorectal cancer but they did have more advanced cancers.
Estrogen therapy (ET) and cancer risk: if you are just taking estrogen therapy instead of EPT, your cancer risks might be slightly different.
The risk of endometrial cancer does increase when you take estrogen therapy according to some studies. The risk remains high even when you stop taking the therapy. The risk was highest for those taking a pill but the patch and vaginal ring can also increase the risk from hormones. Other studies found that EPT does not increase the chance of getting endometrial cancer.
ET is not linked to an increased risk of breast cancer. Some studies have shown that the risk might actually decrease.
The risk for ovarian cancer is low but does increase with estrogen therapy.
Many medical treatments have side effects. Although there is a slight risk of some cancers after taking certain hormone therapies, your doctor may still decide that it is the best course of action and write you a prescription.