Cells throughout the body have hormone receptor. Receptors need to be activated by specific ligands or chemical messengers. The activation of receptor-ligand complex enable cell to receive instructions issued by chemical messengers.

For the ER+ breast cancer cells, the receptor is estrogen receptor while the messenger is hormone estrogen, which circulates in the bloodstream. When the estrogen binds its receptor on the breast cancer cell, it tells the cancer cell to grow and multiply. Therefore, if large numbers of cells in the woman’s breast have these receptors, the message sent by the estrogen is amplified and this cause the cancer cells divide quickly.

Tamoxifen is a medication which mimics the estrogen to seek out and bind to the estrogen receptors on cells throughout the body. Tamoxifen can also be included in a group of medications known as selective estrogen receptor modulators ( SERMs). An ideal SERM should be very selective, which means it only acts as an antagonist or prevents the adverse effects of estrogen in some organ, such as the effect of estrogen in contributing to breast and endometrial cancers. The other positive effects of estrogen are retained, such as the skeletal system to maintain the bone density.

Undeniably, Tamoxifen is a effective and excellent selective estrogen receptor modulator ( SERM ) since it can prevent a first breast cancer from occurring in high-risk women and to decrease the chance of recurrent breast cancer in the patient. Not only that, Tamoxifen has advantage that it acts like estrogen in bone, which help to maintain bone density and reduce the risk of fracture. This help to encounter osteoporosis. Tamoxifen lowers cholesterol, which lessen the likelihood of heart disease too. Unfortunately, it also acts like estrogen in the uterus and circulatory system, which consequently increasing the risks of uterine cancer and blood clots.

According to studies, taking tamoxifen for 5 years provides a greater improvement than taking it for shorter duration. Its positive influence on recurrence and survival continues for years even after women stop taking it.

Nevertheless, there are several question concerned in the use of tamoxifen and need to look for the further studies. Examples are whether tamoxifen is just as effective as chemotherapy for younger women, whether used alone or combined with a therapy that suppresses the ovaries…