While it might seem obvious that women are more likely to get breast cancer, men can get it, too. However, a woman is about 100 times more likely than a man to get breast cancer.
A woman's risk for breast cancer increases with age. In fact, about two-thirds of invasive breast cancers are discovered in women age 55 or older.
Inherited Gene Mutations:
Some genes actually help to prevent cancer. But a mutation, or change, in such a gene could cause it to not work against cancer, thus increasing a woman's risk for breast cancer. Mutations of the BRCA1 and BRCA2 genes are the most commonly inherited.
Women whose periods began before age 12 or went beyond age 55 are at a mildly elevated risk for breast cancer. This could be due to being exposed to more estrogen and progesterone during their lifetime.
The longer a woman waits to have her first child, the higher her risk for developing breast cancer. Furthermore, a woman who never had a child is at an increased risk, too.
Personal or Family History of Breast Cancer:
Women who have a mother, sister, or daughter with breast cancer have about twice the chance of developing the disease, too. If a woman has two such relatives (mother, sister, or daughter) with breast cancer, her own risk is then five times as much. Also, if a woman has had cancer in one breast, she is at an increased risk of developing a new cancer in her other breast.
Race and ethnicity could play a part. Breast cancer is most often diagnosed in white women. However, African-American women are more likely to die from the disease, possibly because their tumors tend to be more aggressive. Latina, Asian, and Native-American women are less likely to develop or die from breast cancer.
Women whose breasts have less fatty tissue and more glandular tissue are considered to have denser breasts. Women with denser breasts are more likely to develop breast cancer. Also, keep in mind that it's more difficult to spot potential trouble spots on a mammogram if a woman has dense breasts.
Studies repeatedly show that the more alcohol a woman consumes, the more likely she is to develop breast cancer. In general, women should not have more than one drink a day.
Overweight and Obesity:
Women who are overweight or obese, in particular after menopause, have an elevated risk for breast cancer. After menopause, the ovaries stop making estrogen, so at that point much of a woman's estrogen comes from her fat tissue. This extra exposure to estrogen could be why women who are overweight or obese after menopause face an increased risk for breast cancer.
Lack of Exercise:
Being physically active could lower breast cancer risk by warding off weight gain and obesity.
Misconceptions About Risk Factors:
Breast implants have not been found to increase the risk of developing breast cancer. However, breast implants could make it more difficult to see breast tissue on a standard mammogram. But there are ways to get around this complication with additional views to better examine the breast tissue.