Who is at risk for breast cancer?
Some risk factors, such as family history, may not be in your control.
But others may be things you can change. Knowing the risk factors can
help you make choices that might lower your risk. For example, if an unhealthy
diet is a risk factor, you may choose to eat healthy foods. If excess
weight is a risk factor, your healthcare provider may check your weight
or help you lose weight.
Risk factors for breast cancer include:
Sex. Breast cancer occurs nearly 100 times more often in women than in men.
Race or ethnicity. Caucasian women develop breast cancer slightly more often than African-American
women. But African-American women tend to die of breast cancer more often.
This may be partly due to the fact that African-American women often have
a more aggressive type of tumor. Why this happens is not known. The risk
for having breast cancer and dying from it is lower in women who are Hispanic,
Native American, or Asian.
Older age. 2 out of 3 women with invasive cancer are diagnosed after age 55.
History of breast cancer. If you’ve had cancer in 1 breast, you’re at an increased risk
of having it in the other breast or another part of the same breast.
Previous chest radiation. If you’ve had high-dose radiation to your chest, you have an increased
chance of breast cancer. The risk is even higher if the exposure happened
when you were a child. It’s important to remember that this involves
high doses of radiation. The small doses used for breast cancer screening
do not increase your risk.
Family history. Having a parent, sibling, or child with breast cancer increases your risk.
Benign breast disease. Women with certain benign breast conditions such as hyperplasia or atypical
hyperplasia have an increased risk of breast cancer. The only way to know
if you have benign breast disease and what kind it is by having a biopsy.
Diethylstilbestrol (DES) exposure. Women who took this medicine while pregnant to lower the chance of miscarriage
are at higher risk. Women whose mothers took DES during pregnancy may
also have a slightly higher risk.
Early menstrual periods. Women whose periods began before age 12 have a slightly higher risk of
Late menopause. Women are at a slightly higher risk if they began menopause after age 55.
Not giving birth to a child, or giving birth to your first child after age 30. These women have a slightly higher breast cancer risk.
Dense breast tissue. Women whose breasts have larger areas of dense tissue on mammograms are
at increased risk for breast cancer.
Recent use (within 10 years) of oral contraceptives. Taking birth control pills slightly increases your breast cancer risk
compared with women who have never used them. The risk may go back to
normal over time after the pills are stopped.
Drinking alcohol. Breast cancer risk goes up if you drink just 1 glass of wine, beer, or
mixed drink a day. The more you drink, the higher your risk. Limit yourself
to less than 1 drink per day.
Long-term use of estrogen and progestin medicines after menopause. This is known as hormone replacement therapy (HRT). The hormones are most
often used together. If you have had HRT for 2 or more years to relieve
menopause symptoms, you may have a higher chance of breast cancer. The
longer you’ve used HRT, the higher your risk. If you stop taking
the medicines, your risk should go back down to normal after 5 years.
Estrogen used alone may not raise your risk much or at all, unless you
use it for more than 10 years. If you decide to use HRT, use it at the
lowest dose and for the shortest time possible.
Excess weight, especially after menopause. This risk factor is complex. Research shows conflicting results about
the link between weight and breast cancer. Overall, your risk of breast
cancer is lower if you stay at a healthy weight with a body mass index
(BMI) below 25. If you’re overweight and you get breast cancer,
the excess weight also affects your chances of being cured.
Certain inherited changes in genes are another risk factor. Hereditary
breast cancer accounts for about 5% to 10% of all breast cancer cases.
The genes linked to breast cancer include:
BRCA1 and BRCA2 genes. These are tumor suppressor genes that usually have the job of controlling
cell growth and cell death. When they're changed, they don't do
their job correctly, and cancer tumors may grow. Changes in these genes
account for most cases of hereditary breast cancer. They're linked
to other kinds of cancer, especially ovarian cancer. In the U.S., BRCA
changes are most common in women of Ashkenazi Jewish ancestry.
PTEN gene. This gene helps control cell growth and death. Inherited changes in this
gene can cause a rare disorder called Cowden syndrome. People with it
have a higher risk for both cancer and non-cancer breast tumors. They
also tend to have tumors in the thyroid, digestive tract, endometrium,
and ovaries, often at a young age.
TP53 gene. This is a gene that tells cells to make a protein called p53. This protein
helps stop the growth of abnormal cells. Inherited changed in TP53 cause
Li-Fraumeni syndrome. People with it have an increased risk breast cancer,
as well as leukemia, brain tumors, and childhood sarcomas. Less than 1%
of all breast cancer is thought to be related to this syndrome.
What are your risk factors?
Talk with your healthcare provider about your risk factors for breast cancer
and what you can do about them. There are different tools that can be
use to help estimate your risk so that you can set up the best prevention
and screening plan for you.