Aromatase Inhibitors as Treatment for Prostate Cancer

Androgen Deprivation Therapy (ADT) is the primary treatment for advanced prostate cancer. A preliminary step in this treatment uses an aromatase inhibitor which may halt cancer but maintain adequate blood levels of testosterone.

Definition

• According to the Medline Plus Medical Dictionary, aromatase is an enzyme that promotes androgen (testosterone) conversion into estrogens. An aromatase inhibitor suppresses this process.

Positive Effects

• According to an article published in 2005 in Oncologist magazine, androgen blockade combined with chemical castration may improve survival and quality of life for advanced prostate cancer patients, particularly when followed by anti-androgen withdrawal and aromatase inhibitors.

Negative Effects

• The use of aromatase inhibitors can cause significant bone loss, according to a report published in the Nov. 20, 2008, issue of the Journal of Clinical Oncology.

Androgen Refractory Prostate Cancer

• Some men become resistant to the ADT because of estrogens as reported in the Oct. 15, 2001, issue of the journal Cancer. A trial testing an aromatase inhibitor found this was unlikely. Therefore, these inhibitors may not have a role in treating this type of prostate cancer.

Aromatase Inhibitors Best Use

• One of the studies supporting use of these inhibitors in breast cancer but not in prostate cancer appeared in the January-February issue of the journal Urologic Oncology. The article concluded aromatase inhibitors show more benefit than anti-estrogens in treating breast cancer, but have not been useful in treating prostate cancer.