It was developed over 20 years ago and has been used to treat both advanced and early stage breast cancer. More recently, tamoxifen is being used as an adjuvant, or additional, therapy following primary treatment for early stage breast cancer.
Tamoxifen is taken by mouth in tablet form and is usually prescribed as a single daily dose.
As a breast cancer therapy, tamoxifen works against the effects of estrogen, which has been shown to promote the growth of breast cancer cells. As a treatment for breast cancer, the drug slows or stops the growth of cancer cells that are already present in the body. As adjuvant therapy , tamoxifen has been shown to help prevent the development and recurrence of breast cancer. Research has shown that when tamoxifen is used as adjuvant therapy for early stage breast cancer, it not only prevents the recurrence of the original cancer but also prevents the development of new cancers in the opposite breast, in many cases. Women considering taking tamoxifen should consult their physician.