Breast Cancer Risk Factors
According to the American Cancer Society, breast cancer is the most frequently diagnosed non-skin cancer in American women. Studies show that the risk of breast cancer increases as women get older. Researchers have identified specific characteristics, or risk factors, which influence a woman's chance of getting the disease.
Breast cancer risk factors include age, breast density, a family's medical history of breast cancer, age of first menses, age at menopause, first child born after age 30 or not having children, history of radiation exposure, smoking cigarettes, alcohol, obesity in postmenopausal women, use of hormonal therapy, history of atypical tissue on previous breast biopsies, and a prior diagnosis of breast cancer.
However, many women who are diagnosed with breast cancer have no known risk factors other than growing older, and statistics show that many women with known risk factors never develop breast cancer through the course of their lives.
You may want to talk to your doctor about ways to try to reduce your risk of breast cancer. Your doctor also may suggest exams that can detect cancer early.
Your doctor's office is one of the best places to keep a regular schedule of annual check-ups and screenings. To select an Alta Bates Summit physician, you can use our Find A Doctor search tool.
For more information about breast cancer risk and risk reduction, please visit the American Cancer Society's Learn About Cancer website 
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Age
According to the Center for Disease Control (CDC) the risk of getting breast cancer increases with age. The table below shows the percentage of women (how many out of 100) who will get breast cancer over different time periods. The time periods are based on the woman's current age.
| Current Age | 10 Years | 20 years | 30 Years |
|---|---|---|---|
| 30 Years Old | .44 | 1.86 | 4.15 |
| 40 Years Old | 1.44 | 3.75 | 6.83 |
| 50 Years Old | 2.39 | 5.57 | 8.62 |
| 60 Years Old | 3.40 | 6.65 | 8.59 |
Percent of U.S. Women Who Develop Breast Cancer over 10-, 20-, and 30-Year Intervals According to Their Current Age, 2004–2006†.
Breast Density
Recent studies indicate that having dense breasts may increase the risk for developing breast cancer.
The density of a breast is measured by the relative amount of different tissues that make up the breast. A dense breast has less fat than glandular and connective tissue. Mammogram films of breasts with higher density are harder to read and interpret than those of less dense breasts.
Family History
According to the American Cancer Society the risk of breast cancer increases by a personal or family history of breast cancer. If you have a parent, sibling, other family members or child who has had breast cancer or any other type of cancer, you may have an increased risk of developing breast cancer. If you have a family history with one or more first-degree relatives who have had cancer in both breasts, specifically before menopause, you may have a higher risk for genetically inherited breast cancer.
However, less than 10% of breast cancer cases are genetically inherited. The majority of women diagnosed with breast cancer do not have a family history of the disease.
Alcohol Use
Many studies have found there is an association between alcohol intake and breast cancer. According to the ACS, the risk increases with the amount of alcohol consumed and is highest among heavy alcohol users.
Tobacco Use
People who smoke are more likely than non-smokers to develop the following cancers: acute myeloid leukemia (cancer of the blood), bladder, breast, cervix, esophagus, kidney, larynx (voice box), lung, mouth, pancreas, stomach, and throat.
The risk of cancer for people who quit is lower than the risk for people who continue to use tobacco. (But the risk of cancer is lowest among those who've never used tobacco.)
For people who have already developed cancer, quitting may reduce the chance of getting another cancer, or the recurrence of cancer.
Hormones
During menopause, doctors may recommend hormones to help control problems such as hot flashes, vaginal dryness, and thinning bones. However, studies show that menopausal hormone therapy may cause serious side effects. Hormones may increase the risk of breast cancer, heart attack, stroke, or blood clots. A woman considering menopausal hormone therapy should discuss the possible risks and benefits.
Diet & Exercise
Diet and exercise are important factors in the overall decrease of risk in cancers. However, in particular, post menopausal women who have a poor diet or are overweight may be at increased risk of several types of cancer. For example, studies suggest that post menopausal women whose diet is high in fat have an increased risk of colon, uterine, and breast cancers. It is also suggested by the American Cancer Society that high dietary fat may be a contributing factor to breast cancer.
The numbers show that the disease is significantly more common in countries where red meat and dairy products are dietary staples, compared to countries where the basic diet consists of rice, soybean products, and vegetables.
Lack of physical activity and being overweight are risk factors for breast, prostate, colon, esophageal, kidney, and uterine cancers.
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For more information on reducing risks for breast cancer, please call the Carol Ann Read Breast Health Center at (510) 869-8377, or Markstein Cancer Education and Prevention Services at (510) 869-8833.
