Hormonal therapies have some side effects in common, and others that differ. Also, different women may respond differently to the same treatment. For some of the newer drugs, such as aromatase inhibitors, clinical trials have not been running long enough to determine all of the long-term side effects.
When discussing your treatment options, ask your doctor about the possible side effects of the hormonal therapies recommended for you. Treatments are often available to help manage the side effects.
All hormonal therapies can cause menopausal symptoms such as hot flushes and vaginal dryness. All hormonal therapies can reduce your libido (sex drive). Treatments are available that can help with these problems – talk to your doctors or breast care nurse if you are troubled by them. The severity of these symptoms varies between women and treatments. These effects often improve after treatment stops.
Treatment with hormonal therapies can sometimes result in permanent menopause. It is important that women who have not yet reached menopause and for whom having children is important discuss their options with a specialist before starting treatment.
Additional side effects of tamoxifen
Rare side effects of tamoxifen include an increased risk of blood clots, stroke, cancer of the uterus and changes in vision. The risk of these side effects needs to be balanced against the fact that anti-oestrogens reduce the risk of breast cancer coming back and death from breast cancer. See your doctor immediately if you are concerned by any new or unusual symptoms, in particular if you have irregular vaginal bleeding, chest pain or warmth, pain, swelling or tenderness in an arm or leg.
Tamoxifen can also have some other benefits in addition to treating your cancer, including reducing the risk of osteoporosis and lowering your cholesterol level.
Additional side effects of aromatase inhibitors
Aromatase inhibitors can cause pain in the bones and/or joints (arthralgia). They also increase the risk of fractures by speeding up the normal thinning of bones that occurs after menopause and with ageing (osteoporosis). If you are already at increased risk of osteoporosis, your doctor will consider this when recommending which hormonal therapy is most suitable for you. Talk to your doctor about how to reduce the risk of fractures and maintain bone strength.
Long-term side effects of aromatase inhibitors are still the subject of ongoing studies. For example, studies are investigating the effects of aromatase inhibitors on memory, concentration and heart disease.
Additional side effects of anti-ovarian treatments
Removal of the ovaries by surgery or radiotherapy to the ovaries causes permanent menopause. Women who have had these treatments can no longer have children. Drugs that stop the ovaries from working also cause menopause, but this is usually temporary, lasting only as long as the drugs are continued. However, the effects of these drugs may be permanent in women who were close to having their natural menopause when they started treatment.
