More than ever before, women are taking an active part in their
breast health. At the center of this change is our growing concern and
understanding of breast cancer, the second most common form of cancer among
women in the United States.
What is breast cancer?
Cells in the body normally divide (reproduce) only when new
cells are needed. Sometimes cells will divide for no reason, creating a mass of
tissue called a tumor. Tumors can be benign (not cancerous) or malignant
In breast cancer, as well as in some other cancers, a tissue
cell becomes abnormal and reproduces without control or order, forming a
malignant tumor. Cancer cells can break off from the tumor, travel to other
parts of the body, and form new tumors. This process is called metastasis.
Metastasis is a late stage of cancer.
Am I at risk for developing breast cancer?
If you are a woman, you are at risk. (Men can also develop
breast cancer, but this is rare.) You may be more likely to develop breast
cancer if you have one or more risk factors, but risk factors do not cause
breast cancer. However, not having a risk factor does not mean that you will not
get breast cancer.
In many cases, it's not known why a woman develops breast
cancer. In fact, 70% of all women with breast cancer have no known risk factor.
What are the risk factors of breast cancer?
A risk factor is anything that increases a person’s chance of
getting a disease. Different cancers have different risk factors.
Significantly higher risk
History of previous cancer in one breast, especially if it
occurred before menopause, increases a woman’s risk of developing a new breast
cancer unrelated to the first one. This is different than a recurrence of the
previous breast cancer.
Genetics also plays a role. Carriers of either of two familial
breast cancer genes called BRCA1 or BRCA2 are at higher risk. Ten percent of
women are carriers of these genes. Also, 10% of all breast cancers are thought
to be from either gene. In addition, the risk of getting breast cancer is up to
85% in a woman’s lifetime if she has inherited these genes.
Moderately higher risk
- Getting older. Your risk for breast cancer increases as you age.
About 77% of women diagnosed with breast cancer each year are over age 50,
and almost half are age 65 and older. Consider this: In women 40 to 49 years
of age, there is a one in 66 risk of developing breast cancer. In the 50 to
59 age group, that risk increases to one in 40.
- Direct family history. Having a mother, sister, or daughter (a
"first-degree relative") who has breast cancer puts you at higher risk for
the disease. The risk is even greater if your relative developed breast
cancer before menopause and had cancer in both breasts. Having one
first-degree relative with breast cancer approximately doubles a woman’s
risk. Having two first-degree relatives with breast cancer increases her
risk five-fold. Having a male blood relative with breast cancer may also
increase a woman’s risk of the disease.
- Breast lesions. These include multiple papillomatosis, atypical
ductal hyperplasia, and lobular carcinoma in situ.
Slightly higher risk
- Distant family history. This refers to breast cancer in more distant
relatives such as aunts, grandmothers, and cousins.
- Large cysts in the breast. Large cysts increase your risk,
especially if accompanied by early atypical hyperplasia (abnormal cell
changes in the breast). A previous breast biopsy result of atypical
hyperplasia increases a woman’s breast cancer risk by four to five times.
- Age at childbirth. Having your first child after age 30 or never
having children puts you at higher risk.
- Early menstruation. Your risk increases if you got your
period before age 12.
- Late menopause. If you begin menopause after age 55, your risk
- Weight. Being overweight (especially in the upper body), with excess
caloric and fat intake, increases your risk, especially after menopause.
- Excessive radiation. This is especially true for women who were
given radiation for postpartum mastitis, received prolonged fluoroscopic
X-rays for tuberculosis, or who were exposed to a large amount of radiation
before age 30 (usually as a treatment for cancers such as lymphoma or
- Other cancer in the family. A family history of cancer of the
ovaries, cervix, uterus, or colon increases your risk.
- Heritage. Female descendents of Eastern and Central European Jews
(Ashkenazi) are at increased risk.
- Race. Breast cancer occurs more frequently in Caucasian women than
in Hispanic, Asian, or African-American women.
- Alcohol. The use of alcohol is linked to increased risk of
developing breast cancer. Compared with nondrinkers, women who consume one
alcoholic drink a day have a 10% increase in risk, and those who have two or
three drinks daily have about 20% to 30% higher risk than women who drink no
alcohol. Alcohol is also known to increase the risk of developing cancers of
the mouth, throat, and esophagus.
- Hormone replacement therapy. Combination estrogen-progestin hormones
taken during menopause increase a woman’s risk of developing breast cancer
by 26%. This risk increases with longer use of hormones.
- Pregnancy before age 18
- Early onset of menopause
- Surgical removal of the ovaries before age 40
Factors not related to breast cancer
- Fibrocystic breast changes
- Multiple pregnancies
- Coffee or caffeine intake
- Underwire bras
- Breast implants
There are other factors that may affect your risk for breast
cancer, but medical research has not yet determined the exact role they play.
One of these is long-term use of birth control pills. Scientists are also
investigating whether smoking, high-fat diets, lack of exercise, and
environmental pollution increase breast cancer risk.
How can I protect myself from breast cancer?
- Get a mammogram:
- Baseline mammogram at age 35
- First mammogram by age 40
- Ages 40 and over: every year
- Examine your breasts each month.
- Have your breasts examined by a health care provider at least once a
Where can I learn more?
NCI Cancer Information Hotline
American Cancer Society
Susan G. Komen Breast Cancer Foundation
5005 LBJ Freeway, Suite 250
Dallas, Texas 75244
Helpline: 800.I'M AWARE® (800.462.9273)
© Copyright 1995-2009 The Cleveland Clinic Foundation. All rights reserved.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 7/10/2009...#3987