Unavoidable Risk Factors
Women acquire breast cancer 100 times more often than men because of their hormones, specifically estrogen and progesterone. The exposure of breast cells in a woman to these growth-drivers accounts for the huge difference.
More than two-thirds of invasive breast cancers are found in women age 55 and older. Only one-eighth of invasive breast cancers are found in women under age 45. Male breast cancer most often strikes those between 60 and 70 years old.
Women have a higher risk of breast cancer if they have a first-degree blood relative (such as a mother, sister or daughter) who has been diagnosed with the disease. Having two first-degree relatives with breast cancer makes a woman five times more likely to develop it.
The genetic mutations of breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2) genes are, by far, the most prevalent causes of inherited breast cancer, accounting for almost the entire 10 percent of cases that are deemed to be hereditary. BRCA mutations may spike the risk to 80 percent in some families. In the U.S., women of Eastern European Jewish background have been found to have disproportionately high BRCA mutations. Other genes that are implicated in hereditary breast cancer, though rare, include ATM, p53, CHEK2, PTEN, and CDH1.
Women of European background are the most likely to be diagnosed with breast cancer, but African American women are more likely to die from the disease. Breast cancer is also the number one cause of cancer death in Hispanic women.
Some physical characteristics that have been shown to increase a woman's risk for breast cancer include:
- Beginning periods before age 12
- Going through menopause after 55 (also called "delayed menopause")
- Having dense breasts
Obesity is a Risk Factor of Breast Cancer. Photo courtesy of Puuikibeach, CC BY 2.0
- Obesity or being overweight
- High alcohol consumption
- Not having children
- Having first child after 35
- Not breastfeeding (according to some studies)
- Taking birth control pills
- Using Hormone Replacement Therapy