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Breast Cancer Causes, Risk Factors, and Prevention

Understanding Breast Cancer

If you are diagnosed with breast cancer, it is important to understand some of the basics as to how this may have happened and what may cause breast cancer. The exact causes of breast cancer are unknown, however there are factors that may increase your risk of developing it.

Breast Cancer Risk Factors

A risk factor is something that may increase your chance of getting a disease. You can avoid some risk factors, like drinking alcohol, but others, like genetics, you can’t. Approximately 75% of women diagnosed with breast cancer have no known risk factors.

High Risk Factors for Breast Cancer

  • Gender: Nearly all breast cancer is diagnosed in women. Less than 1% of breast cancer cases develop in men.
  • Age: Breast cancer risk increases with age.
  • Family history and genetics: If a close relative (mother, sister) has had breast cancer, or if you carry certain genetic mutations (such as the BRCA1 and BRCA2 genes), you have a higher chance of developing breast and/or ovarian cancer.
  • Hormones and childbirth: Extended exposure to estrogen may increase your risk of breast cancer. This could be because you started your period earlier or entered menopause later. Also, if you have had your first child after age 30, never have had children or used hormone therapy after menopause, this may place you at a higher risk.
  • Weight: Women who become overweight or obese after menopause are at higher risk.

Other Risk Factors for Breast Cancer

  • Oral contraceptives: According to the National Cancer Institute (NCI), oral contraceptives may slightly increase the risk of breast cancer.
  • Dense breast tissue: Women with dense breasts are more likely to be diagnosed with breast cancer.
  • Radiation: Young women who underwent radiation treatment to the chest may have a higher risk of developing breast cancer later in life.
  • Poor diet and exercise: A diet high in saturated fats and/or sugar, and a lifetime of physical inactivity increases your risk of developing breast cancer.
  • Alcohol: Studies show that drinking alcohol increases your risk for breast cancer.
  • DES exposure: Women who took a drug called diethylstilbestrol (DES) to prevent miscarriages have a higher risk. And women whose mothers took this drug during pregnancy are also at risk.

Risk Factors for Breast Cancer in Men

Although uncommon, men also develop breast cancer. Many of the risk factors for men are the same for women. However, the following factors may put men are at higher risk:

  • Family history of breast cancer: About 1 out of 5 men with breast cancer have a close relative with the disease.
  • Inherited gene mutations: Certain genetic mutations (such as BRCA2 and BRCA1) are linked to male breast cancer.
  • Klinefelter syndrome: A chromosomal condition that results in higher level of estrogen.
  • Liver disease: Severe liver disease affects hormone regulation, causing lower levels of androgens and higher levels of estrogen.
  • Estrogen treatment: Estrogen drugs, previously used to treat prostate cancer, may slightly increase breast cancer risk. Additionally, transgender/transsexual people who take estrogen could have a higher risk.

Factors that have no known link to Breast Cancer

  • Caffeine
  • Deodorant
  • Microwaves
  • Cell phones
  • Contact with someone who has breast cancer

Reducing Your Risk

While you can’t prevent cancer, it is important to be proactive about your health. You can reduce your lifetime risk of developing breast cancer by:

  • Following your doctor’s health screening guidelines. This includes annual screening mammograms starting at age 40 for women at average risk. Women at higher risk may benefit from supplemental screening tests.
  • Getting a risk assessment from your doctor. If you’re at increased risk, there may be medications you can take.
  • Talking with your doctor about your use of oral contraceptives or hormone therapy
  • Maintaining a healthy weight
  • Eating fruits and vegetables
  • Exercising regularly
  • Stopping tobacco use
  • Limiting your alcohol

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