We teach you about hormonal therapy for breast cancer. Drugs such as tamoxifen and aromatase inhibitors are key treatment options for most breast cancers.
VISIT THE BREAST CANCER SCHOOL FOR PATIENTS:
LIST OF QUESTIONS FOR YOUR DOCTORS:
Questions for your Medical Oncologist:
1. What type of hormonal therapy do you recommend?
2. Will I also benefit from chemotherapy?
3. What are the side effects of hormonal therapy?
4. Will I need 5 or 10 years of these medications?
5. Would the genomic assay Oncotype DX be helpful?
6. What is Hormonal Therapy?
Anti-estrogen (estrogen-blocking) medications, prescribed as pills, are incredibly effective at treating certain types of breast cancer. Hormonal therapy is given to about 70 to 80% of women with breast cancer. Chemotherapy, on the other hand, is a more intense cancer treatment that is generally administered intravenously. Most patients will not need chemotherapy. Many women that do need chemotherapy will also benefit from hormonal therapy. These treatment decisions are complex ones with your medical oncologist. You will make better choices when you are well informed before meeting with your medical oncologist.
Do my “Receptors” suggest Hormonal Therapy?
When the estrogen circulating in your blood stream interacts with a breast cancer that has “Estrogen Receptors” (ER) present on its surface, it tends to flip the ER switch to the “on” or “grow” position for ER Positive tumors. The same can be said to a lesser extent for the “Progesterone Receptor,” if your cancer is found to also be PR positive. Patients with ER+ breast cancers almost always benefit from the anti-estrogen effects of hormonal therapy. These medications can make cancer cells die, or slow down their growth. If a few cancer cells have already spread to other parts of the body, these medications are incredibly effective at preventing these cells from growing and threatening your life in the future. In other words, those who take hormonal therapy for ER+ tumors have a more successful chance at long-term survival when compared to those who do not.
About 80% of all breast cancers are ER+. Even if your medical oncologist recommends chemotherapy for you, if your tumor is ER+ you will also benefit from up to 10 years of hormonal therapy after chemotherapy. Hormonal therapy is never given during chemotherapy nor during radiation therapy.
What is “Tamoxifen?”
Tamoxifen is an anti-estrogen medication (pills) that has been used with great success with ER+ cancers for three decades. It is now the primary hormonal therapy for younger, pre-menopausal women. It is also the primary drug for men with breast cancer. It is used for some post-menopausal women.
What are “Aromatase Inhibitors?”
Aromatase inhibitors (AIs) are a class of anti-estrogen medications (pills) that have proven to be slightly more effective than Tamoxifen for post-menopausal women. It is not recommended for younger, pre-menopausal women, except in certain circumstances. The three most common versions are Anastrozole (Arimidex), Letrozole (Femara), and Exemestane (Aromasin).
What are the side effects of Hormonal Therapy?
Side effects vary greatly from one person to the next for both types of hormonal medications. Some have no symptoms at all. Most have very tolerable side effects. Some patients will need to change hormonal therapy medications to find the best balance of cancer benefit versus side effects. Several side effects that are rather common for both tamoxifen and aromatase inhibitors are hot flashes, night sweats, joint pain, and vaginal dryness. Below, we list some of the other specific side effects for both drugs.
Tamoxifen Side Effects:
Increased risk of uterine (endometrial) cancer
Increased risk of developing blood clots
Slows normal bone loss in most women (a “good” side effect)
Cannot be taken during pregnancy because of risk of birth defects or fetal death
Can temporarily induce menopause in pre-menopausal women.
Aromatase Inhibitor Side Effects:
Can worsen bone loss (osteoporosis) in women
Muscle and joint aches and pains
Would an “Oncotype DX” assay help me?
Patients who have a small, estrogen receptor positive, HER2 receptor negative tumor, and no evidence of cancer in their lymph nodes may benefit from an Oncotype DX genomic assay. This cutting-edge test looks deeper into your cancer cells to better identify people who may also benefit from chemotherapy with ER+ breast cancers. The decision to undergo chemotherapy, in addition to hormonal therapy, is a complicated one. Your medical oncologist uses many factors to help decide if you will benefit from chemotherapy. An Oncotype DX analysis of a portion of your breast cancer tissue can be instrumental in this decision.