Breast Cancer Risk Factors

There are many risk factors for breast cancer. However, having a risk factor does not necessarily mean that a person will get the disease. Some women with one or more breast cancer risk factors never get the disease, while others with no known risk factors will develop the disease. There are different kinds of risk factors. Some risk factors cannot be changed while some are related to personal choices. And, a woman’s risk for breast cancer can change over time.

Breast cancer risk factors a person cannot change include:

  • Gender: Being a woman is the main risk factor for developing breast cancer.
  • Aging: Your risk of developing breast cancer increases as you get older.
  • Genetic risk factors: Recent studies have shown that about five to ten percent of breast cancer cases are hereditary as a result of gene changes (mutations).
  • Family history of breast cancer: Breast cancer risk is higher among women whose close blood relatives have had this disease.
  • Personal history of breast cancer: A woman with cancer in one breast has a three- to four-fold increased risk of developing a new cancer in the other breast.
  • Race: White women are slightly more likely to develop breast cancer than are African-American women.
  • Menstrual periods: Women who started menstruating at an early age (before age 13) or who went through menopause at a late age (after age 51) have a slightly higher risk of breast cancer.

Personal choices that may be risk factors for breast cancer include:

  • Not having children: Women who have no children or who had their first child after the age of 30 have a slightly higher breast cancer risk.
  • Oral contraceptive use: It is still uncertain what part oral contraceptives (birth control pills) may play in breast cancer risk.
  • Hormone replacement therapy (HRT): The American Cancer Society reports that recent research studies have led doctors to re-think the health benefits of HRT. Talk to your doctor about the potential benefits and risks before starting any HRT.                        
  • Breastfeeding: Some studies suggest that breastfeeding may slightly lower breast cancer risks.
  • Alcohol: Use of alcohol is clearly linked to a slightly increased risk of developing breast cancer.
  • Obesity: Being overweight has been found to be a breast cancer risk factor in all studies, especially for women after menopause.
  • Physical activity: Evidence is growing that physical activity in the form of exercise reduces breast cancer risk.

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