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Breast Cancer Fact Sheet
Each year, approximately 40,000 women in the U.S. die from breast cancer and 200,000 new cases are diagnosed. Breast cancer is primarily a disease of older women. Over two-thirds of women diagnosed with breast cancer are 55 years and older.
This fact sheet looks at the risk factors for developing breast cancer, including environmental risk factors, and options for reducing risks. While over 90 percent of American women have at least one risk factor for breast cancer, fewer than 13 percent will ever develop the disease.
Personal Risk Factors
Estrogen-Related Risk Factors
Most well established risks for breast cancer are linked to a woman's lifetime exposure to estrogen. Estrogen is a naturally occurring hormone important for sexual development and child bearing. However, too much estrogen raises the risk for breast cancer. The following factors increase a woman's exposure to estrogen and raise her risk for getting breast cancer.
· Menstruating before age 12.
· Menopause after age 55.
· Hormone replacement therapy for more than 5 years.
· First pregnancy after age 30 or no pregnancies.
· Breastfeeding for less than 12 months (total for all children).
The following factors also increase a woman’s risk for breast cancer:
· Being over 55.
· A previous diagnosis of breast cancer.
· Family history of breast cancer.
· Certain breast diseases, including atypical hyperplasia or lobular carcinoma in situ.
· Dense breast tissue.
Family History
Research consistently has shown that women with a family history of breast cancer are at increased risk for breast cancer themselves. This risk may be due to shared genetic makeup, but may also be due to shared lifestyle choices and exposure to similar environmental risks. In short, having a family history of breast cancer does not necessarily mean your family carries the known breast cancer genes. In fact, most women with a family history of breast cancer do not have such genes. Additionally, women without an apparent family history of breast cancer may have one of the known breast cancer genes.
Genetic Risks
Research suggests that only 5-10 percent of all cases of breast cancer are caused by inherited genetic mutations (or alterations). Scientists have found that mutations in two genes, called BRCA 1 and BRCA2, can cause breast and ovarian cancer. However, scientists now believe that mutations in these two genes account for only half of hereditary breast cancers.
Environmental Risk Factors
Lifestyle Risk and Preventive Actions
What we eat and drink and how active we are play a role in breast cancer. Research has shown that the following lifestyle choices increase a woman's risk for breast cancer:
· Consuming one or more glasses of alcohol a day
· A sedentary lifestyle
· Being overweight (especially after menopause)
By contrast, the following factors have been shown to be protective against breast cancer.
· A diet high in fruit and vegetables
· Regular exercise
Exposure to Environmental Toxins
Controversy exists about the role of environmental toxins and breast cancer. Scientists agree that exposure to high doses of radiation before 30 years of age, such as being treated for Hodgkin's disease, places women at increased risk for breast cancer. Possible, but controversial, environmental risks for breast cancer include:
• Passive smoking (second-hand smoke) and
• PAHs (polycyclic aromatic hydrocarbons) produced by the burning of coal, oil, gas, garbage or other organic substances.
Currently, research has not found a link between breast cancer risk and certain environmental pollutants, such as exposure to electromagnetic fields and certain organochlorine compounds (polychlorinated biphenyls (PCBs), formerly used in consumer and industrial electronics, and DDT/DDE, a now-banned but previously widely used pesticide).
Breast Cancer in African American Women
Facts
Breast cancer is the most common cancer among African American women. African American women are less likely than white women to be diagnosed with breast cancer. However, younger African American women (particularly African American women under the age of 40) have a higher death rate from breast cancer compared to white women of the same age.
Differences in African American Women
Scientists are studying the differences between breast cancer in African American women and other women.
· Breast cancer in black women is usually more advanced with a later stage at diagnosis and worse survival.
· Breast tumors in younger black women are fast - growing and hard to treat.
There may be a number of reasons for these differences including inequalities in income, insurance, and access to screening and treatment, and potentially biologically different cancers.
New Research Findings
In fact, a recent study by researchers at the University of North Carolina found that pre - menopausal women are more likely to get an aggressive form of breast cancer. The Carolina Breast Cancer Study (CBCS) found that when younger, pre - menopausal, black women get breast cancer, they are more than twice as likely as older women, black or white, to get an aggressive breast cancer subtype, called basal-like. This increased likelihood of getting a more aggressive subtype of breast cancer along with the lack of access to proper care and treatment may be the main reasons for the poor survival rate in younger African American women. However, it is still unclear why younger black women are at an increased risk for this more aggressive subtype and further research is needed.
The CBCS is one of the largest black breast cancer databases in the United States and researchers are continuing to find out more about breast cancer in African American women.
Bottom line: All women need regular health care!
Although further research is ongoing, the researchers in this study felt that until we know more, all women should get regular health care and access to adequate health care is extremely important to screen for and treat breast cancer.
For more information on the Carolina Breast Cancer Study
visit, http://cbcs.med.unc.edu/ or call 866-927-6920.
Resources for low-cost or free mammograms:
- Your local health department orSusan G. Komen Breast Cancer Foundation’s Nation Toll-Free Breast Care Helpline at 1.800 I’M AWARE.
References
American Cancer Society. Cancer Facts & Figures for African Americans 2007-2008. Atlanta: American Cancer Society, 2007.
American Cancer Society. Breast Cancer Facts & Figures 2007-2008. Atlanta: American Cancer Society, 2007.
UNC Healthcare News Release. Study: Breast cancer in younger black women is more likely to be an aggressive variety. June 6, 2006. www.unchealthcare.org/site/newsroom/news/2006/Jun/breastcancer
UNC Healthcare News Release. UNC Lineberger launches 44 county study of breast cancer in black women. October 30,2008. http://www.unchealthcare.org/site/newsroom/news/2008/October/millikan/
Carey L, Perou C, Livasy C, Dressler L, Cowan D, Conway K, Karaca G, Troester M, Tse Chiu, Edmiston S, Deming S, Geradts J, Cheang M, Nielsen T, Moorman P, Earp S, Millikan R. Race, Breast Cancer Subtypes, and Survival in the Carolina Breast Cancer Study. The Journal of the American Medical Association, June 7, 2006; vol 295: pp 2492-2502.
Where to Go for More Information
American Cancer Society, 800-277-2345, www.cancer.org
FORCE (Facing Our Risk of Cancer Empowered), www.facingourrisk.org
National Cancer Institute Cancer Information Service, 800-4-CANCER, http://www.cancer.gov/cancertopics/factsheet/Information/CIS
National Breast Cancer Coalition, 202-295-7477, http://www.stopbreastcancer.org/
North Carolina Breast Cancer Resource Directory, 800-514-4860, bcresourcedirectory.org
UNC-Chapel Hill Cancer Genetics Clinic, 919- 843-8724, cancer.med.unc.edu/patient/programs/cancer-genetics.asp (for genetic counseling)
The Community Outreach and Education Core of the UNC-Chapel Hill Center for Environmental Health and Susceptibility produced this fact sheet with a grant from the National Institute of Environmental Health Sciences (NIEHS), P30ES10126. This fact sheet accompanies a workshop, Breast Cancer, Genes, and the Environment.
For more information about the workshop, please contact Neasha Graves by phone (919) 966-3746
or email neasha_graves@unc.edu.
