Breast cancer is a group of diseases which stem from mutations in normal breast cells, causing the cells to proliferate out of control. Breast cancer is extremely prevalent--over 194,000 cases of breast cancer were diagnosed in the United States in 2009, according to the National Cancer Institute. Surgical removal of the tumor, and/or drug or radiation therapy can treat breast cancer, though there is a chance of breast cancer recurrence either in the same or the opposite breast. A number of treatments have been developed to treat recurring breast cancer.
Tamoxifen
Tamoxifen is a breast cancer drug that belongs to a general class of therapeutics known as selective estrogen receptor modulators, which means that they block estrogen signaling. Estrogen is a female hormone released by the ovaries that stimulates breast cell growth. Some forms of breast cancer are also stimulated by estrogen, which produces a proliferative response in the tumor cells. Estrogen signaling increases the risk of breast cancer recurrence by promoting proliferation, potentially accelerating the development of a new breast tumor.
Tamoxifen works by binding to the estrogen receptor, a protein found on the surface of breast cells that senses estrogen and signals for cell proliferation. In the presence of Tamoxifen, the cells no longer proliferate in response to estrogen, so Tamoxifen can be used to prevent or treat breast cancer.
Arimidex
Arimidex is another type of hormone therapy used to treat recurrent breast cancer. It belongs to a class of drugs known as aromatase inhibitors, which function to decrease the amount of estrogen released into the bloodstream. Arimidex works by preventing the formation of estrogen in the ovaries, so it is never released into the blood and cannot signal to breast cells. It may be used alone or in combination with other hormone therapies to treat or prevent breast cancer recurrence.
A report published on MedicalNewsToday.com states that Arimidex may be more effective than Tamoxifen in preventing breast cancer recurrence. Clinical trial results indicate that a five-year Arimidex treatment prevented cancer recurrence in post-menopausal women more often than Tamoxifen treatment. Arimidex may also be effective in cases where prior Tamoxifen treatment has failed.
Evista
Like Tamoxifen, Evista is a selective estrogen receptor modulator, so it blocks the binding of estrogen to the estrogen receptor protein. Evista is prescribed to post-menopausal women, especially if they also suffer from osteoporosis, since Evista also treats bone disorders.
Large clinical trails have shown that Evista is able to reduce the risk of invasive breast cancer at a rate comparable to Tamoxifen, according to the National Cancer Institute. Additionally, Evista appears to have fewer side effects than Tamoxifen--clinical trials showed a lower risk of developing uterine cancer or blood clots. Therefore, Evista may be a good treatment option for breast cancer recurrence for women who have adverse reactions to Tamoxifen.
