1 in 8 women will be diagnosed with breast cancer during her lifetime. A scary statistic! But knowledge is power and knowing about the risk factors linked to breast cancer can help you to be vigilant.
What are risk factors?
A risk factor is anything that increases a person’s chance of getting a disease such as cancer.
- Some risk factors are linked to a person’s lifestyle choices, such as smoking, drinking of alcohol and diet, and can be changed.
- Other risk factors, such as a person’s age or family history, cannot be changed.
Having a risk factor, or even a gene, does not mean that you will definitely get the disease.
Some women who have one or more risk factors never get the breast cancer, and many women who develop breast cancer don’t have any risk factors.
While all women are at risk for breast cancer, the factors below may increase her chances of developing the disease.
Risk factors you cannot change
Simply being a woman increases the chances of developing breast cancer over a man’s. While men also get breast cancer, it is 100 times more common in women that in men.
This is the strongest risk factor for developing breast breast cancer. The chance of getting breast cancer increases as a women gets older.
About 2 out of 3 women with invasive breast cancer are age 55 or older when cancer is found.
Personal history of breast cancer
A woman with cancer in one breast has a greater chance of getting a new cancer in the other breast, or in another part of the same breast.
This is different from a return of the first cancer (which is called recurrence).
Breast cancer risk is higher among women whose close blood relatives have this disease. The relatives can be from either the mother’s or father’s side of the family.
The more family members affected, the younger they were at diagnosis and the closer they are related: the higher the chance of breast cancer in that individual.
Breast cancers linked to positive genes make up the minority (5-10%) of breast cancer cases. The most common gene changes that have been identified as being linked with breast cancer are those of the BRCA1 and BRCA2 mutations. Women with these gene changes have an increased risk of getting breast cancer during their lifetimes.
There are tests that can tell if a woman has certain changed (mutated) genes linked to breast cancer. With this information, women can then take steps to reduce their risks. If you are thinking about genetic testing, you should talk to a genetic counsellor, nurse or doctor qualified to explain the nature and possible outcomes of these tests.
It is very important that you know what genetic testing can and can’t tell you, and to weigh the benefits and risks of testing carefully before these tests are done.
Dense breast tissue
Dense breast tissue means there is more glandular tissue and less fatty tissue. Women with denser breast tissue have a higher risk of breast cancer. Dense breast tissue can also make the breast tissue more difficult to examine and more difficult for doctors to identify problems on mammograms.
Women who began having periods early (before age 11) or who went through the change of life (menopause) after the age of 55 have a slightly increased chance of getting breast cancer.
Risk factors influenced by lifestyle choices
Not having children or having them later in life
Women who have not had children, or who had their first child after age 30, have slightly higher risk of breast cancer.
Use of birth control pills
Studies have found that women who are using birth control pills have a slightly greater risk of breast cancer (however, they also a lower risk of ovarian cancer!) than women who have never used them.
Women who stopped using the pill more than 10 years ago do not seem to have any increased risk. It’s a good idea to talk to your doctor about the risks and benefits of birth control pills.
Hormone replacement therapy (HRT)
This has been used for many years to help relieve symptoms of menopause and to help prevent thinning of the bones (osteoporosis). It has become clear that long-term use (several years or more) of the combined forms of HRT increases the risk of breast cancer.
There are some good reasons to use HRT other than for short-term relief of menopausal symptoms. Because there are other factors to think about, women should talk to their doctors about the advantages and disadvantages of using HRT.
If a woman and her doctor have decided to try HRT purely for relief of menopausal symptoms, it is usually best to use it at the lowest effective dose and the shortest time possible.
Some studies have shown that breastfeeding slightly lowers breast cancer risk, especially if the total combined time of breastfeeding lasts at least a year or two.
Use of alcohol is clearly linked to an increased risk of getting breast cancer. Try to limit the amount to one drink a day, if at all.
Being overweight or obese
Being overweight or obese is linked to a higher risk of breast cancer, especially for women after menopause – if the weight gain took place during adulthood.
The risk also seems to be higher if the extra fat is in the waist area. The link between weight and breast cancer is complex. It is recommended that you maintain a healthy weight throughput your life.
Lack of exercise
Studies show that exercise reduces breast cancer risk. This may be because exercise helps control weight. The only question is how much exercise is needed.
Studies found that breast cancer is less common in countries where the typical diet is low in fat.
Eating a healthy, low-fat diet that includes 5 or more servings of vegetables and fruits each day, choosing wholegrain products instead of refined starches.
Nutrition experts recommend limiting the amount of processed and red meats as well.
A possible link to breast cancer is yet another reason to stop smoking and avoid being around secondhand smoke.
Many of us can make some adjustments to our lifestyle choices, which may lower our risk of getting breast cancer.
What if you are at increased risk of breast cancer?
You can reduce your chances if you are an extremely high risk candidate, based on your family history or genetics. This could include chemoprevention or preventive surgery. Before deciding which, if any, of these may be right for you, talk with your doctor.
Chemoprevention is the use of drugs to reduce the risk of cancer. Many drugs have been studied for use in lowering breast cancer risk.
Preventive surgery for women with very high breast cancer risk
For the few women who have a very high risk for breast cancer, preventative surgery such as bilateral (double) mastectomy, or oophorectomy (removal of the ovaries) may be an option.
The reasons for thinking about this type of surgery need to be very strong. There is no way to know ahead of time whether this surgery will benefit a particular woman.
A second opinion is strongly recommended before making a decision to have this type of surgery.