Aromatase Inhibitors or Tamoxifen

Last Modified: February 20, 2009

Question

Dear OncoLink "Ask The Experts,"

I am post-menopausal and have been prescribed an aromatase inhibitor. Why am I receiving this when it seems like tamoxifen is the more common prescription? How can I deal with the hot flashes caused by this drug?

Answer

Carolyn Vachani RN, MSN, AOCN, OncoLink's Nurse Educator, responds:

Tamoxifen is the drug of choice for premenopausal women with hormone receptor-positive breast cancer. This is based on how it works. The main source of estrogen in premenopausal women is the ovaries. Tamoxifen is an antiestrogen or estrogen blocker, which works by blocking estrogen receptors in breast tissue. While estrogen may not actually cause breast cancer, it is necessary in order for the cancer to grow in some breast cancers. With estrogen blocked, the cancer cells that feed off estrogen may not be able to survive.

The aromatase inhibitors go a step further, by preventing the estrogen from being produced. In women who have gone through menopause, estrogen is mainly produced by converting androgens (sex hormones produced by the adrenal glands) into estrogens. An enzyme called aromatase is responsible for this conversion. Aromatase inhibitors block this conversion, leading to less estrogen in the body. These drugs have been found to be more effective at preventing cancer recurrence in post menopausal women.

As for dealing with the side effects of hot flashes, see this previous question.

Blogs

How to Find the Cancer Resources You Need - Brown Bag Web Chat
by OncoLink Editorial Team
June 15, 2011

Don't Assume You Understand
by Bob Riter
July 29, 2015

Related News

Aromatase Inhibitors May Be More Effective Than Tamoxifen

Jul 30, 2015

Long-term treatment with AIs linked to lower cancer recurrence, possibly fewer cancer deaths


Treatments with exemestane alone or following tamoxifen have different side effects

Jan 19, 2011

Treatments with exemestane alone or following tamoxifen have different side effects


Exercise Eases Arthralgia Caused by Aromatase Inhibitors

Dec 11, 2014

Aerobic activity and strength training reduce pain in previously inactive breast cancer survivors