Hormonal adjuvant chemotherapy for breast cancer patients

Hormonal adjuvant chemotherapy refers to treatment of breast cancer patients before or after surgery. The estrogen receptor, a component of human cells, is often found to be aberrant in breast cancers. The way the receptor acts is by uptaking chemical signals called 'estrogen'. To combat this, researchers have developed a drug called 'tamoxifen'. It was found that treatment of patients with tamoxifen (which mimics estrogen but competes with it) turns down the activity of the aberrant estrogen receptor. Both early breast cancers in men and women can be treated with tamoxifen. Clinical studies show that when used as adjuvant chemotherapy, hormone treatment suppresses recurrence of the original cancer, as well as diminishing cancers that occasionally arise in the other breast.

In addition to tamoxifen for hormone therapy, there are newer drugs (which nevertheless behave like tamoxifen) that are more potent or have beneficial effects such as suppressing development of other cancers. Raloxifen is one such newer drug. Remarkably, one more beneficial side effect of tamoxifen is that it reduces bone loss caused by osteoporosis. However, tamoxifen hormonal therapy also suffers from adverse side effects, such as increasing the risk of endometrial and uterine cancers. This is understood to be due to tamoxifen's uneven effects on these other tissues.