About one in eight women will develop cancer during their lifetime. While researchers do not know why cancer occurs, they have identified several factors that increase a person’s risk for breast cancer.
- Being a woman – While men can also develop breast cancer, the disease is 100 times more common among women than men.
- Family history – “There has been much media coverage about the BRCA1 and BRCA2 gene mutations, which are linked with breast cancer,” says Carlos Robles, MD, medical oncologist/hematologist at Saint Francis Medical Center. “But a very small percentage of breast cancer patients have one of those two genes. Family history is a much more important indicator of breast cancer risk.”
- Personal history of breast cancer – Any woman who has had breast cancer in one breast has a threefold to fourfold increased risk of developing a new cancer in another part of that breast or in the other breast. This is apart from recurrence of the same cancer.
- Aging – Two out of three invasive breast cancers are found in women
55 and older.
- Dense breast tissue – Women who have more glandular and fibrous
tissue in their breasts and less fatty tissue are at higher risk for developing breast cancer.
- Obesity – Having more fat tissue after menopause raises the estrogen levels in your body, which can increase your risk for breast cancer.
- Pregnancy-related factors – Women who have had no children or who had their first child after age 30 have a slightly higher risk for breast cancer. “This risk factor is related to the balance between progesterone and estrogen in a woman’s body,” says Robles. “When a woman is pregnant, she does not have the peaks of estrogen production that are associated with having a menstrual cycle. This lowers breast cancer risk.”