The Known Breast Cancer Risk Factors
Anything that increases your risk of getting a disease is called a risk factor. While there is no sure way to prevent breast cancer, there are things you can do that might lower your cancer risk. Knowing the risk factors for breast cancer is the first step in taking control of your health. Many of the cancer risk factors are under your control and are also the same changes that we need to make to enjoy living a healthier life. It’s a Win-Win!
Breast cancer risk factors that you cannot change:
- Being a Woman – Just being a woman is the biggest risk factor for developing breast cancer.
- Age – About two out of three invasive breast cancers are found in women 55 or older.
- Family History – For women with one first-degree female relative (sister, mother, daughter) diagnosed with breast cancer, the risk is doubled.
- Genetics – About 5% to 10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child.
- Personal History of Breast Cancer – If you’ve been diagnosed with breast cancer, you’re 3 to 4 times more likely to develop a new cancer in the other breast or a different part of the same breast.
- Race/Ethnicity – White women are slightly more likely to develop breast cancer than African American, Hispanic, and Asian women. But African American women are more likely to develop more aggressive, more advanced-stage breast cancer that is diagnosed at a young age.
- Certain Breast Changes – If you’ve been diagnosed with certain benign (not cancer) breast conditions, you may have a higher risk of breast cancer. There are several types of benign breast conditions that affect breast cancer risk. (read more)
- Having Dense Breasts – Research has shown that dense breasts can be 6 times more likely to develop cancer and can make it harder for mammograms to detect breast cancer.
- Menstrual History – Women who started menstruating (having periods) younger than age 12 have a higher risk of breast cancer later in life. The same is true for women who go through menopause when they’re older than 55.
The breast cancer risk factors that you have some or total control over:
- Pregnancy History – Women who haven’t had a full-term pregnancy or have their first child after age 30 have a higher risk of breast cancer compared to women who gave birth before age 30.
- Breastfeeding History – Breastfeeding can lower breast cancer risk, especially if a woman breastfeeds for longer than 1 year.
- Radiation to Chest or Face Before Age 30 – If you had radiation to the chest to treat another cancer (not breast cancer), such as Hodgkin’s disease or non-Hodgkin’s lymphoma, you have a higher-than-average risk of breast cancer. If you had radiation to the face at an adolescent to treat acne (something that’s no longer done), you are at a higher risk of developing breast cancer later in life.
- Using HRT (Hormone Replacement Therapy) – Current or recent past users of HRT have a higher risk of being diagnosed with breast cancer. Since 2002 when research linked HRT and risk, the number of women taking HRT has dropped dramatically.
- DES (Diethylstilbestrol) Exposure – Some pregnant women were given DES from the 1940s through the 1960s to prevent miscarriage. Women who took DES themselves have a slightly higher risk of breast cancer. Women who were exposed to DES while their mothers were pregnant with them also may have a slightly higher risk of breast cancer later in life.
- Drinking Alcohol – Research consistently shows that drinking alcoholic beverages — beer, wine, and liquor — increases a woman’s risk of hormone-receptor-positive breast cancer.
- Being Overweight – Overweight and obese women have a higher risk of being diagnosed with breast cancer compared to women who maintain a healthy weight, especially after menopause. Being overweight also can increase the risk of the breast cancer coming back (recurrence) in women who have had the disease.
- Lack of Exercise – Research shows a link between exercising regularly at a moderate or intense level for 4 to 7 hours per week and a lower risk of breast cancer.
- Smoking – Smoking causes a number of diseases and is linked to a higher risk of breast cancer in younger, premenopausal women. Research also has shown that there may be a link between very heavy second-hand smoke exposure and breast cancer risk in postmenopausal women.
- Low of Vitamin D Levels – Research suggests that women with low levels of vitamin D have a higher risk of breast cancer. Vitamin D may play a role in controlling normal breast cell growth and may be able to stop breast cancer cells from growing.
- Light Exposure at Night – The results of several studies suggest that women who work at night — factory workers, doctors, nurses, and police officers, for example — have a higher risk of breast cancer compared to women who work during the day. Other research suggests that women who live in areas with high levels of external light at night (street lights, for example) have a higher risk of breast cancer.
- Eating Unhealthy Food – Diet is thought to be at least partly responsible for about 30% to 40% of all cancers. No food or diet can prevent you from getting breast cancer. But some foods can make your body the healthiest it can be, boost your immune system, and help keep your risk of breast cancer as low as possible.
- Exposure to Chemicals in Cosmetics – Research strongly suggests that at certain exposure levels, some of the chemicals in cosmetics may contribute to the development of cancer in people. (read more)
- Exposure to Chemicals in Food – There’s a real concern that pesticides, antibiotics, and hormones used on crops and livestock may cause health problems in people, including an increase in breast cancer risk. There are also concerns about mercury in seafood and industrial chemicals in food and food packaging. (See the 2017 EWG List of the Dirty Dozen and the Clean 15 is below)
- Exposure to Chemicals for Lawns and Gardens – Research strongly suggests that at certain exposure levels, some of the chemicals in lawn and garden products may cause cancer in people. But because the products are diverse combinations of chemicals, it’s difficult to show a definite cause and effect for any specific chemical.
- Exposure to Chemicals in Plastic – Research strongly suggests that at certain exposure levels, some of the chemicals in plastic products, such as bisphenol A (BPA), may cause cancer in people.
- Exposure to Chemicals in Sunscreen – While chemicals can protect us from the sun’s harmful ultraviolet rays, research strongly suggests that at certain exposure levels, some of the chemicals in some sunscreen products may cause cancer in people.
- Exposure to Chemicals in Water – Research has shown that the water you drink — whether it’s from your home faucet or bottled water from a store — may not always be as safe as it could be. Everyone has a role in protecting the water supply. There are steps you can take to ensure your water is as safe as it can be.
- Exposure to Chemicals When Food Is Grilled/Prepared – Research has shown that women who ate a lot of grilled, barbecued, and smoked meats and very few fruits and vegetables had a higher risk of breast cancer compared to women who didn’t eat a lot of grilled meats.
Exposure to Chemicals in Food
“The Dirty Dozen” are the 12 most contaminated fruits and vegetables according to the EWG analysis (see the newest dirty dozen and clean fifteen lists and get the latest news about Pesticides in Produce), so you may want to consider buying these organic if you can: strawberries, spinach, nectarines, apples, peaches, pears, cherries, grapes, celery, tomatoes, sweet bell peppers, and potatoes
“The Clean 15” are fruits and vegetables that are likely to have little contamination, so you may want to buy non-organic types of these foods if cost is an issue: sweet corn, avocados, pineapple, cabbage, onions, sweet peas (frozen), papayas, asparagus, mango, eggplant, honeydew, kiwi, cantaloupe, cauliflower, and grapefruit*
*Like pomegranate, grapefruit may interfere with some medications and treatments. Talk to your doctor about whether it’s safe to consume grapefruit.
* A small amount of sweet corn, papaya and summer squash sold in the United States is produced from genetically modified seeds. Buy organic varieties of these crops if you want to avoid genetically modified produce.
This post was created as a supplement to Understanding Breast Cancer. Be sure to visit this post to learn more about National Breast Cancer Awareness Month and Breast Cancer.