In patients who have completed surgical operations and chemotherapy, if their tumors are sensitive to estrogen and/or progesterone (if the tumors carry hormone receptors), hormone drugs (hormone therapy) that are structurally similar to these hormones but have a suppressive effect are given.
Breast cancer is thought to be closely related to women’s hormonal balance. Long-term exposure to estrogen (starting menstruation early and entering menopause late), never giving birth or giving birth to the first child after the age of 35 are risk factors in the development of breast cancer. The main source of the estrogen and progesterone hormones in the body is the ovaries.
As a result of studies based on these relationships, it has been determined that some agents showing anti-estrogen effect may have a protective property against breast cancer. It has been shown that women who have receptors (sensors) for the estrogen or progesterone hormones in their cancer cells will benefit from agents that bind to these receptors and block the effects of the hormones.
What Are the Hormone Therapy Agents?
The most commonly used anti-estrogen agent for this purpose today is tamoxifen. In recent years, apart from tamoxifen, other agents with different mechanisms of action but similar effectiveness have also been developed (such as aromatase inhibitors).
Hormone Therapy for Prevention
Tamoxifen can also be used for prevention in patients at high risk of developing breast cancer. The duration of use for this purpose is 5 years, and they reduce the risk by an average of 40-50% only during the time they are used.
What Are the Side Effects?
Tamoxifen may cause menopause-like symptoms to appear early on. With long-term use it has been associated with uterine cancer. For this reason the duration of use is limited to 5 years in premenopausal women.
Aromatase inhibitors given after menopause have some side effects such as causing bone loss and joint pain. For this reason, according to bone density measurements taken before and after the drug is given to patients, calcium supplementation is given if necessary and some additional medications may be given by physical therapy specialists.
