How Does Tamoxifen Treat Breast Cancer?

…..Science HealthTamoxifen is a common endocrine treatment for both early and advanced breast cancer in pre- and post-menopausal women.  Some breast cancer cells are stimulated to grow in the presence of the estrogen hormone.  The estrogens bind to special areas in the cancer cells called estrogen receptors, and once the estrogens are attached, the cancer cells’ growth is enhanced.  These breast cancers are called estrogen receptor positive.

 …..Tamoxifen breaks down in the body into a compound that also binds to the estrogen receptor in the cancer cell, but it does not stimulate the cancer cell to grow.  Since the binding site is filled, any available estrogen cannot attach to the cancer cell and stimulate its growth.

…..After the diagnosis and treatment of a breast cancer that was estrogen receptor positive, many patients would be placed on 5 years of tamoxifen treatment, and this would reduce the recurrence of the disease.  New studies may cause oncologists to change the protocol to 10 years of tamoxifen treatment due to the findings of better long-term outcomes.  There are currently ongoing studies which should shed more light on the possibility of modifying the protocols.

…..I would like to touch upon two other points.  As with all medications, tamoxifen can have side effects.  Endometrial cancer is increased with the use of tamoxifen, and so oncologists follow patients closely for this potential problem.  Lastly, another group of medications, called aromatase inhibitors, is now being used more frequently with these patients, but worldwide tamoxifen remains widely used.

-Dr. P

9 Replies to “How Does Tamoxifen Treat Breast Cancer?”

Leave a Reply