Patients who have completed surgical operations and chemotherapy are given hormone drugs (hormone therapy) that are structurally similar to these hormones but suppressive if their tumors are sensitive to estrogen and/or progesterone (if their tumors carry hormone receptors).

Breast cancer is thought to be closely related to women’s hormonal balance. Prolonged exposure to estrogen (early onset of menstruation and late menopause) and never giving birth or having the first birth after the age of 35 are risk factors for developing breast cancer. The ovaries are the main source of estrogen and progesterone hormones in the body.

As a result of studies based on these relationships, it has been found that some agents with anti-estrogen effect may have protective properties against breast cancer. Women whose cancer cells have receptors for the hormones estrogen or progesterone have been shown to benefit from agents that bind to these receptors and block the effects of the hormones.

What are Hormonotherapy Agents?

The most widely used anti-estrogen agent for this purpose is tamoxifen. In recent years, other agents other than tamoxifen have been developed with different mechanisms of action but similar efficacy (such as aromatase inhibitors).

Hormonotherapy 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% in the period of use alone.

What are the Side Effects?

Tamoxifen can cause early menopause-like symptoms. Long-term use has been associated with uterine cancer. The duration of use in pre-menopausal women is therefore limited to 5 years.

Aromatase inhibitors given after menopause have some side effects such as causing osteoporosis and joint pain. For this reason, patients are given calcium supplements and some additional medications may be prescribed by physical therapists, if necessary, according to bone density measurements taken before and after the medication is given.