MedicineWorld.Org - Cancer - Hormonal Therapy for Breast Cancer
Estrogen and progesterone are female hormones produced by ovaries. A breast cancer is said to be hormone receptor positive if shows evidence of estrogen or progesterone receptors (cell components that will bind to these female hormone molecules to bring about changes with in the cell). Laboratory tests are performed after surgery or biopsy to determine if the breast cancer cells are hormone receptor positive. Hormone receptor positive breast cancer is depended on estrogen hormone for multiplication and growth and it is rational to block the hormones on which the tumor cells are feeding. Contrary to many people’s belief; hormonal therapy is a more effective form of breast caner adjuvant therapy compared to chemotherapy. Most of the clinical trials have shown better results with hormonal agents compared to chemotherapy. If combined with chemotherapy, hormonal therapy would give even better results. There are several drugs available to block the hormones. We will briefly describe each of the most common hormone blocking drugs available for the treatment of breast cancer.
Tamoxifen (Nolvadex) is a hormonal drug that blocks the estrogen to the tumor cells. It is in pill form and is taken daily by mouth. Use of tamoxifen as adjuvant therapy has shown to markedly decrease the risk of cancer recurrence in patients with hormone receptor positive breast cancer. In the adjuvant setting it is usually giver for a period of 5 years....
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Read more about Tamoxifen
Raloxifene: Raloxifene (Evista)
This is a drug that acts just like tamoxifen, and blocks the effect of estrogen on breast tumor cells. At this time it is not proven to decrease the risk of breast cancer from coming back and should not be substituted for tamoxifen. Raloxifene is currently undergoing clinical trial to determine its efficiency in reducing risk of developing breast cancer.
Toremifene: Toremifene (Fareston)
This is another hormonal agent that blocks the estrogen hormone. Its properties are similar to tamoxifen and effective in breast cancer treatment. This drug could be an alternative option for patients with metastatic breast cancer who are hormone receptor positive or have an unknown hormonal status.
Fulvestrant: Fulvestrant (Faslodex)
FDA has recently approved this drug for use in patients with hormone receptor positive metastatic breast cancer. In contrast to tamoxifen, which blocks the estrogen receptors, fulvestrant destroys the estrogen receptors on the tumor cells. Breast cancer patients who had progression of disease
on previous hormonal agents like tamoxifen may respond to fulvestrant. Unlike tamoxifen this drug is given as an intravenous injection and is given once in 4 weeks. Like tamoxifen, fulvestrant may also cause hot flashes. Mild nausea, and fatigue are other major side effects of this drug.
This is group of drugs with abilities to block an enzyme called aromatase, which is responsible form production of small amounts of estrogen in post-menopausal women whose ovaries are no longer functioning. A group of drugs called aromatase inhibitors work by blocking this enzyme thus decreasing its level in post-menopausal women....
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Read more about Aromatase inhibitors
Another way of blocking the estrogen hormone is to do an ovarian ablation. This is done in pre-menopausal women only because the ovaries of post-menopausal women are not functional. There are different choices for the ovarian ablation. Ovarian ablation can be done surgically, by removing the ovaries. It can also be done using drugs called luteinizing hormone-releasing hormone (LHRH) agonists. These are hormones called follicular stimulating hormone (FSH) and luteinizing hormone (LH), which control the activities of the ovaries. LHRH agonists interfere with the action of these hormones which results in the failure of the ovarian hormonal function. These drugs are now undergoing clinical trial for use in the setting of adjuvant hormonal therapy of breast cancer. Leuprolide (lupron) is one such drug.
Megestrol acetate (Megace): is a drug that behaves like the female hormone progesterone. This drug was widely used in the past for the treatment of metastatic breast cancer, but with the development of better drugs this drug has gone to the back seat, however this drug may be still used for patients with hormone receptor positive metastatic breast cancer which is not responding to more common hormonal drugs like tamoxifen or aromatase inhibitors. Major side effect associated with drug is weight gain. Because of this weight gaining effect this drug is often used in patients with advanced cancer and AIDS to stimulate appetite and reverse the weight loss caused by these conditions.
Androgens (male hormones)
These hormonal agents may be tried if all other hormonal treatments for a patient with metastatic breast cancer fail These drugs may lead to development of masculine characteristics like more body hair and a deeper voice, nevertheless they are sometimes effective.
|Hormonal Therapy for Breast Cancer|