Prevention Options

Breast Cancer Prevention Options

Since no one knows the cause of breast cancer, there is no guaranteed method of breast cancer prevention. However, we can offer the most comprehensive services to reduce your risk of developing breast cancer and, should cancer develop, to detect it as early as possible. Read on for more information on:

1. Models to evaluate your risk factors

Gail Model: The Gail Risk Assessment Model is a statistical model for estimating the risk of developing breast cancer in women undergoing annual screening.(1) It takes certain risk factors into account in order to quantify your individualized risk of developing breast cancer. Your physician will calculate your Gail score (your risk of developing breast cancer) within five years and over your lifetime. In this way, your risk can be compared to the risk of an average woman in your age group.

The five significant predictors of risk taken into account by the Gail Model are:

Current age
Age at menarche
Age at first live birth
Number of breast biopsies
--If one or more, did biopsy show atypical hyperplasia?
Number of first-degree relatives with breast cancer

Claus Model: The Claus Model estimates the probability that a woman will develop breast cancer based on her family history of cancer. Since the Gail Model only takes into account first-degree relatives (mother, sister, daughter), the Claus Model may provide a more complete calculation of risk from family history because it also takes into account second-degree relatives with cancer and the age of cancer onset. (2)

2. Recommendations about Lifestyle

Maintain a Healthy Bodyweight and Pay Attention to Your Nutrition: Because an association between obesity and increased risk of breast cancer has been established, eating healthfully to maintain a healthy body weight is one of the most important actions you can take. In this binder, you will find specific suggestions about how to improve your nutrition. If you are interested in having an individualized consultation, please inquire about a visit with our nutritionist.

Although there are no clear associations between certain foods and an increased risk of breast cancer, experts agree that a healthy diet should encourage good fats (monounsaturated and polyunsaturated) over bad fats (saturated and hydrogenated), and should include plenty of fruits, vegetables, and whole grains, balanced with physical exercise, to maintain a healthy bodyweight.

Increase Physical Activity: Besides helping to maintain a healthy bodyweight, physical activity itself could be a protective factor against developing breast cancer regardless of bodyweight. Recommended exercise is 30 minutes of moderate activity at least five times a week. Forty-five minutes of moderate to vigorous activity may further reduce risk against breast and colon cancer.(3)

Exercise doesn't necessarily mean using the treadmill five days a week. It could mean walking, biking, jogging, gardening, ice-skating, playing team sports, doing yoga, or dancing. If you are sitting in a chair at work for eight hours a day, your body probably deserves to move 30 minutes a day!

Decrease Alcohol Intake: By decreasing your alcohol consumption to one drink a day, you may be able to reduce your breast cancer risk. Studies suggest that further reducing your consumption will further lower your risk. One drink per day is generally the suggested maximum.(4)

Do Not Smoke Cigarettes: Though not linked to breast cancer, smoking is strongly discouraged because of its effects on overall health. Also try to encourage the young people in your life not to start smoking. The Center for Disease Control reports that among people who have ever smoked daily, 71% began smoking daily before the age of 19.(5)

Be Selective When Choosing Hormone Therapies: When making a decision about whether to use oral contraceptives or hormone replacement therapy (HRT), it is a good idea to discuss your other risk factors for breast cancer with your doctor.

ORAL CONTRACEPTIVES - We do not discourage the use of oral contraceptives because they have not been associated with a signifi cant increase in breast cancer risk, and they have been associated with a reduced risk of ovarian cancer. However, since oral birth control works by maintaining estrogen levels over a woman's cycle, this estrogen exposure may slightly increase risk for breast cancer. Furthermore, unwanted pregnancy is itself associated with many risks. When a woman is deciding whether to use oral contraceptives, she must weigh the risks of unwanted pregnancy against the slightly increased risk of breast cancer.
HORMONE REPLACEMENT THERAPY - For many years, women were automatically given hormone replacement therapy because of the theories that it slowed aging and reduced heart disease, in addition to relieving menopausal symptoms. Now that small increases in the incidence of heart disease, stroke and breast cancer have been observed in women taking hormone replacement therapy (combined estrogen and progestin), women can make a more informed decision by weighing the benefits and risks of HRT.

3. Learning More About Your Risk to Help in Decision-Making

Certain tests can give more information about your risk. This is called risk refinement. It can be helpful to know more about your risk so that you and your physician can choose the most effective screening strategies for you.

SERUM ESTRADIOL MEASUREMENT
The procedure: Blood is drawn.
The test: The amount of estradiol in your blood is measured in a lab.
How it may teach you more about your risk: Research has suggested that women who have higher levels of estradiol may benefit more from taking raloxifene. A recent study showed that when women who had the highest levels of serum estradiol were taking raloxifene (a medicine similar to tamoxifen), they had a 76% risk reduction as compared to a placebo group. Conversely, when women had no traces of serum estradiol in their blood and were taking raloxifene, their risk reduction was zero as compared to a placebo group. As a woman's level of serum estradiol increased, her percent risk reduction from taking raloxifene increased.(7)

GENETIC TESTING
The procedure: Blood is drawn.
The test: DNA is checked for the presence of mutations in the BRCA1 or BRCA2 genes.
How it may teach you more about your risk: Although carrying a BRCA1 or BRCA2 gene mutation does not mean a woman will surely develop cancer, it puts her at significantly higher risk. Some women will choose to be tested for a gene mutation because they have several relatives with breast and/or ovarian cancer and feel information can help them make more informed decisions about screening and preventive surgery. Other women will find the option of testing more likely to provoke anxieties than to relieve them. Counselors with the UCSF Cancer Risk Program can help determine the individualized benefits that you would have from testing and help you decide whether testing is appropriate for you.

4. Increased Surveillance

ROUTINE SCREENING
Screening Mammography: A mammogram is a low-dose x-ray of the breast. This is the best test we have to screen women for breast cancer. A screening mammogram consists of two "pictures" of each breast. If an area on the mammogram looks suspicious or is not clear, additional mammograms with different views may be needed.

Recommendations regarding screening with mammography in the U.S. range from having annual mammograms starting at age 40, to having mammograms every 2 years from ages 50-75. Importantly, for women 40-49, the US Preventive Task Force Guidelines call for patients and their physicians to make an individual decision, taking into account family and personal history of cancer as well as factors like a history of previous biopsies, age at menarche, age of child bearing, intake of alcohol, smoking habits, diet, weight, prior radiation therapy and/or hormone replacement therapy. Of course, paramount to good decision making is understanding the benefits and risks of screening. Screening has benefits, but it also has some limitations. It is important for clinicians and patients to be aware of these so that we make the most of the information we get from screening.

Women with relatives who had breast cancer at a young age may want to consider beginning their annual mammograms before age 40. We recommend that these women begin having annual mammograms 10 years before the age at which the first family member was diagnosed. For instance, if your aunt was diagnosed with breast cancer at age 40 and your mother at age 45, we would recommend that you started having mammograms ten years before your aunt's age at diagnosis: age 30.

If a woman has a family member diagnosed before the age of 35, we generally recommend that the woman begin having mammograms no earlier than age 25.

Clinical Breast Exam (CBE): The clinical breast exam allows a clinician to check the breasts for any abnormalities. While it is impossible for a clinician to find every cancer with a CBE, the clinical breast exam is an essential part of a woman's screening. Depending on your level of risk, your clinician may ask that you have a clinical breast exam once every six months or once a year.

Breast Self-Exam (BSE): A monthly breast self-exam is an excellent way to be familiar with your body and any changes it may be going through. Cancers are frequently found when a woman notices a lump in her breast and brings it to the attention of her nurse or doctor. If you would like to learn more about how to do a breast self-exam, please ask about making a Mammacare appointment.

SCREENING FOR A SUSPICIOUS LUMP OR A DIAGNOSED CANCER
Diagnostic Mammography: This is a mammogram used for problem-solving, rather than for screening. For instance, if a woman has a lump in her breast, that area is specifically targeted with diagnostic mammograms. This type of mammogram is also done when a particular finding (like calcifications) in the breast is being followed over time. A diagnostic mammogram is tailored to the patient's case and is carefully monitored by a radiologist, who interprets the images and determines whether any further tests are needed.

Ultrasonography: Using high-frequency sound waves, ultrasonography can often show whether a lump is solid or filled with fluid (like a cyst). This exam may be used along with Diagnostic Mammography to answer questions about a specific area of the breast. Because it uses sound waves instead of x-rays, ultrasound provides information that is different and often complementary to the mammogram.

Breast MRI: Magnetic Resonance Imaging (MRI) can be used to look specifically at the breast. Each exam produces hundreds of images of the breast, cross-sectional in all three directions (side-to-side, top-to-bottom, front-to-back), which are then read by a radiologist. It is non-invasive and no radioactivity is involved. The technique is believed to have no health hazards in general. The hope is that such non-invasive studies will contribute to our progress in learning how to predict the behavior of tumors, and in selecting proper treatments. Breast MRI is an evolving technology and should not replace standard screening and diagnostic procedures (clinical and self exams, mammogram, fine needle aspiration or biopsy).

5. Chemoprevention

Tamoxifen is the only therapy currently approved to reduce the risk of breast cancer in women who are at high risk. It is in a class of drugs called selective estrogen receptor modulators (SERMs). Tamoxifen works as an anti-estrogen in the breast, meaning it reduces the amount of estrogen to which breast cells are exposed.

The most common side effects of tamoxifen are hot flashes and increased vaginal discharge or vaginal dryness. Side effects that are serious but less common include uterine cancer, blood clots, cataracts, and strokes.(8) Important to note is that women under age 50 suffered very few serious side effects compared to women over age 50.(9)

Raloxifene is also a selective estrogen receptor modulator (SERM). It was observed that the rates of breast cancer were lower in women with osteoporosis taking raloxifene than women who were taking a placebo. Research on raloxifene continues to evaluate its efficacy.

6. Preventive surgery

Prophylactic oophorectomy is the surgical removal of the ovaries in order to reduce the risk of ovarian and/or breast cancer. Because the ovaries make estrogen, removing the ovaries causes early menopause in premenopausal women and thus can cause menopausal symptoms. A study published in the New England Journal of Medicine in May 2002 showed that women with a BRCA gene mutation who underwent prophylactic oophorectomy were about 50% less likely to develop breast cancer than women with a mutation who did not undergo the same surgery.(10)

Prophylactic mastectomy is the surgical removal of one or both breasts in order to reduce the risk of developing breast cancer. Women who have already had one breast removed because of cancer may be interested in this option, as well as women who have extensive family history of breast cancer and/or who have a BRCA mutation. Prophylactic mastectomy has been shown to reduce the risk of breast cancer by up to 90%, but it is not a guarantee that cancer will never develop.(11) Before making the very serious and personal decision to have a preventive mastectomy, a woman should gather as much information as she can, and discuss her risks and benefits with a physician.

7. Health Risks in Context

In the next ten years, an average 50-year old woman has a...

RISK OF DIAGNOSIS FROM:

breast cancer 2.5-3.0%

RISK OF DEATH FROM:

lung cancer(smoker) 2.0-3.0%
heart attack 0.5-2.5%
breast cancer 0.3-0.7%
lung cancer (non-smoker) 0.2-0.3%
accidents 0.2%

OTHER RISKS THIS YEAR ALONE:

Increase in breast cancer
(for each year of HRT use) 0.1-0.5%
Injured in an automobile accident 8%
Visit the doctor about the flu 38% (12)

References

Gail M.H., Brinton L.A., Byar D.P. et al. Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst, 1989. 81: p. 1879-86
Fisher B., Costantino J.P., Wickerham D.L., Redmond C.K., Kavanah M., Cronin W.M. et al. Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study. J Natl Cancer Inst, 1998 Sep 16. 90(18): p. 1371- 88
American Cancer Society Nutrition and Physical Activity Guidelines for Cancer Prevention, 2002.
Singletary K.W., Gapstur S.M. Alcohol and breast cancer: review of epidemiologic and experimental eidence and potential mechanisms. JAMA, 2001 Nov 7. 286(17): p. 2143-51
Prevention. Preventing Tobacco Use Among Young People, A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, 1994
Fisher B., Costantino J.P., Wickerham D.L., Redmond C.K., Kavanah M., Cronin W.M. et al. Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study. J Natl Cancer Inst, 1998 Sep 16. 90(18): p. 1371- 88
Cummings S.R., Duong T., Kenyon E., Cauley J.A., Whitehead M., Krueger K.A. Serum estradiol level and risk of breast cancer during treatment with raloxifene. JAMA, 2002 Jan 9. 287(2): p. 216-20
Fisher B., Costantino J.P., Wickerham D.L., Redmond C.K., Kavanah M., Cronin W.M. et al. Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study. J Natl Cancer Inst, 1998 Sep 16. 90(18): p. 1371- 88
Gail M.H., Costantino J.P., Bryant J., Croyle R., Freedman L., Helzlsouer K. et al. Weighing the Risks and Benefi ts of Tamoxifen Treatment for Preventing Breast Cancer. J Natl Cancer Inst, 1999 Nov 3. 91(21): p. 1829-1846
Rebbeck T.R., Lynch H.T., Neuhausen S.L., Narod S.A., Van�t Veer L., Garber J.E., et al. Prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations. N Engl J Med, 2002 May 23. 346(21): p. 1616-22
Newman L.A., Kuerer H.M., Hung K.K., Vlastos G., Ames F.C., Ross M.I., Singletary S.E. Prophylactic mastectomy. J Am Coll Surg, 2000 Sep. 191(3): p. 322- 30
Woloshin S., Schwartz L.M., Welch H.G. Risk charts: putting cancer in context. Journal of the National Cancer Institute, 2002 Jun 5. 94(11): p. 799-804