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Aromatase Inhibitors for Breast Cancer
Aromatase inhibitors are a type of medication that stops estrogen production in postmenopausal women.
Since aromatase inhibitors were introduced in the late 1990s, the FDA has approved three of them for treating breast cancer. They are:
Currently, aromatase inhibitors are not approved for reducing the risk of developing breast cancer.
What is hormone therapy?
Hormones are chemicals in the blood that control the growth and activity of normal, healthy cells. Certain hormones, however, such as estrogen, can also fuel the growth of some breast cancers.
Estrogen promotes the tumor growth in about two out of three breast cancers. Estrogen helps cancer cells grow by binding to a protein called an estrogen receptor, which is found in some breast cancer cells. (These are called estrogen-receptor positive [ER+] breast cancers.) When estrogen binds to this receptor, the cancer cells divide and the tumor grows.
A variety of hormone therapy drugs block estrogen's effect on breast cancer. They do this in several ways:
Aromatase inhibitors reduce the amount of estrogen in the body.
Tamoxifen and Fareston (toremifene) block estrogen from binding to its receptor.
Faslodex (fulvestrant) acts on the estrogen receptor by blocking estrogen from binding and by reducing the number of available estrogen receptors.
Hormone therapies work only against tumors that grow in response to estrogen; that is, those that have estrogen receptors. An ER+ status shows that the tumor may respond to hormone therapy. All breast cancers should be tested for this when they are diagnosed.
How aromatase inhibitors work
If you have not yet gone through menopause, your ovaries still produce most of the estrogen in your body. After menopause, your ovaries no longer make large amounts of estrogen. Cells in your muscles and fat, however, still produce some estrogen from male hormones called androgens.
Aromatase inhibitors work by blocking the production of estrogen from androgens. These drugs interfere with the enzyme called aromatase. Its role is to convert androgens, such as testosterone, into estrogen. By interfering with estrogen production, aromatase inhibitors deplete the body of estrogen. This helps slow or stop the growth of ER+ breast tumors, sometimes even shrinking them.
Researchers have found that the drugs cannot lower estrogen levels enough to affect tumor growth in younger women. That's because their ovaries still make high levels of estrogen. For this reason, aromatase inhibitors are used only in women who have gone through menopause.
Aromatase inhibitors are not all the same. As listed above, there are three drugs that stop estrogen production by blocking the enzyme aromatase. All three are taken daily as pills.
An evolving role
For postmenopausal women who might respond to hormone therapy, most doctors now recommend using an aromatase inhibitor at some point during adjuvant therapy. Adjuvant therapy is treatment given in addition to the major treatment. Its purpose is to prevent or delay any remaining cancer cells from growing. However, several questions remain unanswered. It is not clear if starting adjuvant therapy with one of these drugs is preferable to giving tamoxifen and then switching to an aromatase inhibitor. It is also not clear how long to give tamoxifen or how long to give an aromatase inhibitor. Research is now being done to answer these questions.
Side effects and risks
In general, aromatase inhibitors do not cause serious short-term side effects. These are the most common side effects. They're listed in alphabetical order. Ask your doctor which ones you are most likely to experience:
These are usually mild. If you do have side effects, you're more likely to have them in the first few weeks. Only in rare instances do side effects require that the treatment be stopped.
Aromatase inhibitors rarely cause blood clots. However, they do increase the risk for bone thinning, which can develop from a lack of estrogen. This can make bones more brittle and likely to break. Talk with your doctor about what you can do to prevent or manage bone problems, such as exercising and taking calcium. Drugs called bisphosphonates can prevent or reverse bone loss. Talk with your doctor about whether you need them.
Because estrogen has healthful effects on the heart and on brain function, researchers are looking into the effects these drugs may have on these organs. Ongoing research will more clearly determine the long-term risks and benefits associated with the use of aromatase inhibitors.
Broward Health Receives Grant to Help Women Navigate Breast Cancer Treatment
Find out more details about the Breast Cancer Navigator Program »
Broward Health provided 29,380 mammograms last year, nearly 3,000 of them for women who had no insurance and could not afford to pay. While a mammogram may be essential in detecting abnormalities, a diagnosis is meaningless without follow-up. That follow-up – particularly for poor women – can be daunting.
A grant of nearly $150,000 from the Florida Division of the American Cancer Society will help Broward Health set up a new Breast Cancer Patient Navigator Program to ensure that more women living in poverty will get the medical care they need after an abnormal mammogram or a diagnosis of breast cancer. The goal is to ensure half of the participants are African-American, Caribbean or Hispanic.
A “navigator” case manager will provide one-on-one assistance to women of any age in navigating the complexities of not only scheduling, testing and treatment, but with things like childcare, transportation, translation services and understanding medical terminology as well.
The navigator case manager will oversee the woman’s care throughout treatment at the Comprehensive Cancer Centers at Broward Health facilities (Broward Health Medical Center and Broward Health North). If the woman doesn’t show up for an appointment, stops treatment, or becomes unreachable after two weeks, the case manager will go to her home to check on her and find out why she hasn’t kept her appointments. The case manager will then work with her to get her back on track. When cancer goes into remission, the case manager will continue to monitor her health and quickly set up doctor appointments and further treatment if needed.
The navigator program is dedicated to dismantling barriers faced by medically underserved women with breast cancer, increasing access to healthcare services and ultimately improving quality of life.
Breast Cancer Patient Navigator Program Participants
September 2006 – July 2008
The American Cancer Society awarded Broward Health the Breast Cancer Patient Navigator Program Grant in September 2006 to navigate medically underserved women of all ages (living below 200% of the Federal Poverty Level who receive an abnormal mammogram), from diagnostic mammogram to breast cancer survivorship. The two (2) year grant award provided for one (1) Registered Nurse Breast Cancer Patient Navigator to remove the barriers to care by providing one-on-one case management once breast cancer is diagnosed.
The program allows for:
- Earlier identification/intervention
- Greater outreach to our community
- A broader range of services
- Decreased treatment variability
- Increased effectiveness of care
- 282 female and 2 male patients, ages 15 thru 85
- 57 dependent children
- Treatment and diagnostic sites – 1-49 miles from patients' home
- Transportation – 60% of the patients were brought to the health care site by friend or family; 34% by private car; 6% used taxi service or public transportation provided by Broward Health
Race/Ethnicity (Claritas 2007)
37% - Black Non Hispanic
51% - Black Non Hispanic
23% - Hispanic
18% – Hispanic
19% - White Non Hispanic
25% - White Non Hispanic
9% - Haitian
3% - Asian
7% - Other
3% - Other
2% - Asian
1% - Portuguese
- 284 - patients referred from Broward Health sites and the Broward County Health Department's Breast & Cervical Cancer Initiative
- 109 - patients that did not meet guidelines (i.e. had insurance, were enrolled in another program, received care at another facility, refused services)
- 63 - patients disenrolled from the program (i.e. eligibility changed, moved, changed providers, chose homeopathic treatment and/or refused treatment, treatment complete and patients are following up with primary care physician for a yearly mammogram)
- 37 - patients in the program with no diagnosis of breast cancer that are being followed.
- 75 - patients with diagnosis of breast cancer – majority of the cases is invasive ductal carcinoma. (61 ductal, 5 intra ductal, 4 multi focal, 3 lobular, 1 mucinous & 2 multi centric)
1 - stage 0
7 - stage I
31 - stage II
18 - stage III
6 - stage IV
12 - in staging process
- Broward Health hospitals and Community Health Service sites, i.e., Broward Health Medical Center, Broward Health North, Broward Health Imperial Point, and Broward Health Coral Springs.
- Broward Health Website
- Florida Breast Cancer Resource Network
- Broward County Health Department through its Breast & Cervical Cancer Initiative (BCCI)
- Other community organizations, i.e., Living Water clinics, Light of the World, churches, etc.
- Private physician offices, friends, and family
Benefits of Program
Access & Compliance
Patients adhered to their scheduled appointments. In the event of a scheduling conflict, the Breast Cancer Patient Navigator was contacted for resolution.
Transportation and certification process has been expedited because of intervention by Breast Cancer Patient Navigator.
97% of the patients adhered to the treatment plan (3% sought alternative treatment or chose treatment elsewhere).
Care & Treatment
Recommended diagnostic procedures:
- Spot magnification / compression
- Stereo tactic biopsy
- Ultrasound biopsy
- CT Scans, Mir's & PET Scans
- Echocardiograms, Lab work, X-rays and ultrasounds
Recommended treatment procedures:
- Hormonal treatment
97% of the patients adhered to scheduled diagnostic procedures
Current status of patient treatment
29 – in treatment (chemo/radiation)
30 – in post treatment
6 – refused treatment
6 – in work-up
1 – out of service area
3 – out of country
Knowledge and Education
Educational components made available to all the patients:
- Initial education packet
- American Cancer Society Breast Cancer Guidelines
- National Cancer Institute Breast Cancer Booklet
- Chemotherapy and You
- Triple Touch
- Knowledge & Education
- Demand Mailings – specific topics of interest
- Support groups and education classes
- Look Good, Feel Better
- Gilda's Club
- Reach to Recovery
- Community Church Support Group