Some breast tumors need hormones to grow. Hormone therapy keeps cancer cells from getting or using the natural hormones they need--estrogen and progesterone. Lab tests can show if a breast tumor has hormone receptors. If you have this kind of tumor, you may require hormone therapy.
This treatment uses drugs or surgery:
- Drugs Tamoxifen blocks estrogen. Another type of drug prevents the body from making the female hormone estradiol. Estradiol is a form of estrogen. This type of drug is an aromatase inhibitor. If you have not gone through menopause, your doctor may give you a drug that stops the ovaries from producing estrogen.
- Surgery If you have not gone through menopause, you may require surgery to remove your ovaries. The ovaries are the main source of the body's estrogen.
The side effects of hormone therapy depend largely on the specific drug or type of treatment. Tamoxifen is the most common hormone treatment. In general, the side effects of tamoxifen are similar to some of the symptoms of menopause. The most common are hot flashes and vaginal discharge. Other side effects are irregular menstrual periods, headaches, fatigue, nausea, vomiting, vaginal dryness or itching, irritation of the skin around the vagina, and skin rash. Not all women who take tamoxifen have side effects.
It is possible to become pregnant when taking tamoxifen. Tamoxifen may harm the unborn baby. If you are still menstruating, you should discuss birth control methods with your doctor.
Serious side effects of tamoxifen are rare. However, it can cause blood clots in the veins. Blood clots form most often in the legs and in the lungs. Women have a slight increase in their risk of stroke.
Tamoxifen can also cause cancer of the uterus. Your doctor should perform regular pelvic exams and you should tell your doctor about any unusual vaginal bleeding between exams.
When the ovaries are removed, menopause occurs at once. The side effects are often more severe than those caused by natural menopause. Your health care provider can suggest ways to cope with these side effects.