One in five postmenopausal women with estrogen-positive breast cancer do not take the newer chemoprevention hormone therapy aromatase inhibitor drugs to prevent recurrence as prescribed, according Dana-Farber Cancer Institute and AstraZeneca Pharmaceuticals researchers who conducted a study to determine drug usage.

Aromatase inhibitors, such as Anastrozole, have been shown to be an effective means of blocking estrogen that fuels cancer for women diagnosed with estrogen-positive breast cancer, and Dana Farber's Dr. Ann Partridge warns that, "Women may be compromising their care, and ultimately their survival, if they do not take these medications as recommended."

Despite warnings, a significant number of women are choosing to discontinue use and the researchers of this survey can only speculate as to the reasons why. Some of the reasons they believe play a role in the women's decision not to comply with recommended treatment are: fear of side effects, actual experience of side effects, cost of treatment, and negative health beliefs that treatment will not help.

From a personal insight, the most common reason I know of as to why women are not taking this medication, or discontinue usage, is the fact that these drugs do not have a long history of use, and one can only guess what the possible, and presently unknown, long-term side effects will end up being. While Dr. Partridge states without a shadow of a doubt that these new aromatase inhibitor drugs are effective in breast cancer recurrence, only time itself will remedy the hesitation and non-compliance.

Some of the aromatase inhibitors include Anastrozole (Arimidex), Letrozole (Femara), Exemestane (Aromasin) and Formestane (Lentaron). To learn more about aromatase inhibitors, visit the National Cancer Institute's aromatase inhibitors digest.