Skip to content

Breast Cancer Health Center

Font Size

Breast Cancer: Comparing Hormone-Blocking Treatments - Topic Overview

When breast cancer is described as estrogen-receptor-positive (ER+), it means that estrogen helps these breast cancer cells grow. Hormone therapy is used in ER+ breast cancer to reduce the body's production of estrogen or to block its effects. This is done to stop the growth of cancer cells.

Hormone-blocking treatments, such as tamoxifen or an aromatase inhibitor, act on cells all over the body but generally cause fewer side effects than chemotherapy. If you are deciding what type of medicine to use, weigh the side effects and risks along with the benefits for your type of cancer.

Comparing hormone-blocking treatments

Drug names

tamoxifen (Nolvadex) anastrozole (Arimidex), exemestane (Aromasin), letrozole (Femara)

Class of drug

Selective estrogen receptive modulator (SERM)Aromatase inhibitor

What it does

Blocks harmful estrogen in the breastLimits how much estrogen the body makes

Treats breast cancer?

Yes, before and after menopauseYes, after menopause (instead of or after tamoxifen)

Side effects and risks

Side effects can include hot flashes and vaginal dryness.

Increased risks of:

Side effects can include hot flashes, vaginal dryness, muscle/body ache, mild nausea, diarrhea/constipation, weakness, and fatigue.

Increased risk of osteoporosis after 5 years of treatment for women who started out with weak bones (osteopenia)

When taking tamoxifen, you will need a pelvic exam every year. If you have any vaginal bleeding, other than normal menstrual bleeding, tell your doctor as soon as possible. This can be a sign of uterine precancer or cancer.

Neither chemotherapy nor hormone therapy is likely to cure breast cancer that has spread to another area of the body (metastasized). But each of these treatments can reduce symptoms and may prolong life.

1

WebMD Medical Reference from Healthwise

Last Updated: June 28, 2011
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Breast Cancer: Comparing Hormone-Blocking Treatments Topics

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
 
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
 
Breast Cancer Treatments Improving
VIDEO
Resolved To Quit Smoking
SLIDESHOW
 
Woman getting mammogram
Article
Screening Tests for Women
SLIDESHOW
 
ovarian cancer overview slideshow
SLIDESHOW
serious woman
Article
 
what is your cancer risk
HEALTH CHECK
10 Ways to Revitalize Slideshow
SLIDESHOW