By Guest Blogger Robin Amylon
October is Breast Cancer Awareness Month, so today we will explore the risk factors for breast cancer. Breast cancer is the most common cancer among American women. It is also the second leading cause of cancer death in women (lung cancer being the first). About 1 in 8 women in the US will develop breast cancer during their lifetime. The American Cancer Society estimates that by the end of this year about 232,340 new cases of breast cancer will be diagnosed in women and about 39,620 women will die from breast cancer.
What Are the Risk Factors for Breast Cancer?
A risk factor is anything that affects your chances of getting a disease, however, it does not necessarily mean you will get the disease. Many women who have one or more risk factors never get breast cancer, while others who have no apparent risk factors do. Some risk factors can’t be changed, such as your age or race, but others such as your lifestyle (diet, physical activity, alcohol use) can. Below is a list of the most common risk factors for breast cancer. Risk Factors You Cannot Change:
- Gender: Women are at higher risk of developing breast cancer than men. This is due to the fact that men have lower amounts of the female hormones estrogen and progesterone, which can promote breast cancer cell growth.
- Aging: As you get older your risk of developing breast cancer increases. About 1 out of 8 women who are 55 years old.
- Genetic Risk Factors: About 5-10% of breast cancer cases are thought to be hereditary. These cases are due to gene defects (mutations) inherited from a parent.
- Family History of Breast Cancer: If you have a blood relative who has breast cancer your risk increases. Having a mother, sister or daughter with breast cancer doubles your risk, while having a grandmother, granddaughter, aunt or niece with breast cancer triples your risk.
- Personal History of Breast Cancer: a woman with cancer in one breast is 3-4 times more likely to develop a new cancer in the other breast or in another part of the same breast.
- Race and Ethnicity: Caucasian women are slightly more likely to develop breast cancer than African-American women, however, African American women are more likely to die from breast cancer. Asian, Hispanic and Native-American women have a lower risk of developing and dying from breast cancer.
- Dense Breast Tissue: The breast is made up of fatty, fibrous and granular tissue. Dense breast tissue occurs when you have more granular and fibrous tissue and less fatty tissue. A number of factors can affect breast density, such as age, menopausal status, certain drugs, pregnancy and genetics.
- Menstrual Periods: Women who started menstruating before the age of 12 and/or started menopause after the age of 55 have a slightly higher risk of breast cancer. This risk may be due to a longer lifetime exposure to the hormones estrogen and progesterone.
Lifestyle-Related Risk Factors (Risk Factors You Can Change):
- Having Children: Women who don’t have children or had their first child after the age of 30 have a slightly higher risk of getting breast cancer. Women who have had multiple pregnancies and became pregnant at a young age, however, are at lower risk. Pregnancy reduces a woman’s total number of lifetime menstrual periods, which may be the reason for this effect.
- Birth Control: Studies have found that women who use birth control pills have a slightly greater risk of breast cancer than women who never used them.
- Hormone Therapy After Menopause: Hormone therapy (either with estrogen alone or combined with progesterone) is used to help relieve symptoms of menopause and prevent osteoporosis in older women. There are two types of hormone therapy:
- Combined Hormone Therapy:
- Both estrogen and progesterone are prescribed.
- Used for women who still have a uterus.
- Increases breast cancer risk and may also increase chances of dying from breast cancer.
- Estrogen Therapy:
- Only estrogen is prescribed.
- Used for women who have had a hysterectomy (no longer have a uterus).
- Does not appear to increase breast cancer risk.
- Some research suggests women who have had their uterus removed and take estrogen actually have a lower risk of breast cancer.
- Combined Hormone Therapy:
- Breastfeeding: Some studies suggest that breastfeeding may slightly reduce breast cancer risk.
- Alcohol Use: Alcohol consumption has clearly been linked to an increased risk of developing breast cancer. The risk increases depending on the amount of alcohol consumed. Compared to non-drinkers, those who have 2-5 drinks per day are about 1.5 times more likely to develop breast cancer.
- Being Overweight or Obese: If you are overweight or obese after menopause you have a greater risk of developing breast cancer. After menopause, most of a woman’s estrogen comes from fat tissue. The more fat tissue you have the higher your estrogen levels will be which increases your risk. Women who are overweight also have higher levels of insulin which has been linked to certain cancers, including breast cancer.
- Physical Activity: Many studies have shown that physical activity can reduce breast cancer risk. One study found that as little as 1.25-2.5 hours per week of brisk walking reduced a woman’s risk by 18%.
- Diet: Some studies have found that a diet rich in vegetables, fruit, poultry, fish and low-fat dairy products has been linked to a lower risk of breast cancer.
Make sure to check in for Part Two of this article tomorrow, which focuses on preventative measures against breast cancer.
Robin Amylon is an NYC-based Nutritionist. She received her Bachelor of Science from Queens College in Nutrition and Exercise Science and is currently finishing a program at New York-Presbyterian Hospital to become a Dietitian.