About one in eight U.S. women (about 12.4%) will develop invasive breast cancer. Almost everyone is impacted by breast cancer in some way. The key to curing breast cancer is prevention, early diagnosis and aggressive therapy.
Changes in mutations in DNA can cause normal breast cells to become cancer. Certain DNA changes are inherited and can increase your risk for breast cancer and hormones seem to play a role, but how this happens is not fully known. There are other lifestyle-related risk factors, such as diet and exercise that can increase one’s chance of developing breast cancer, but it’s not yet known exactly how some of these factors cause normal cells to become cancer. The majority of women who develop breast cancer have no clear risk factors.
The strongest risk factors for developing breast cancer are gender and age. Breast cancer is 200 times more common in women than men. Breast cancer is 400 times more common in older women (age 50) than younger women (age 20). Caucasian and Jewish women have the highest incidence of breast cancer. Women of color, such as African American have a lower rate of breast cancer, but a higher mortality. Asian women have the lowest risk of breast cancer. It is helpful to understand your risk factors, so that you can modify what you can and monitor what you cannot.
Women with a history of breast cancer have an increased risk of developing breast cancer again during their lifetime. These women must be closely monitored by a medical professional for the rest of their lives. Women who stay free of breast cancer for five years are encouraged that they may not get the cancer again. However, women may still develop breast cancer again even after being free of breast cancer for 20 years or more.
Family history of breast cancer increases an individual’s personal risk of developing breast cancer, and family history of breast cancer plus ovarian cancer in the same person further increases this risk.
The majority of patients that get breast cancer do not carry the breast cancer gene, known as BRCA1 and BRCA2. Most likely, there are additional genes that have not been identified yet. If an individual has a strong family history of breast cancer, she should get tested for BRCA1 and BRCA2.
Women who carry the gene have a significantly increased risk of getting breast cancer, as well as other cancers, including ovarian, colon, lung, and pancreatic cancer. Since the majority of women who get develop breast cancer do not have the BRCA gene, absence of the gene does not guarantee that you will not get breast cancer. Talk to a breast cancer specialist to determine if you should be tested for the BRCA gene and to discuss monitoring and prophylactic therapy options if you carry the gene. Mammograms, physical exams, blood work, tamoxifen therapy, and/or surgery may be indicated.
Particular cells found in breast tissue, called pre-cancers such as Atypical Ductal Hyperplasia (ADH) and Atypical Lobular Hyperplasia (ALH) also increase the risk of breast cancer. These are identified by breast biopsy. Lobular Carcinoma in Situ (LCIS) is considered a cell marker that increases the risk for of breast cancer, but it is not a cancer itself. More frequent monitoring is recommended in these cases and more aggressive treatment may be indicated if additional risk factors are identified.
The term “null parity” means a woman has never given birth to a child. Null parity women have a slightly increased risk of breast cancer. When a woman is pregnant, the hormone cycle gets interrupted and this decreases the risk of breast cancer, particular if a woman is pregnant before age 30.
In addition, the younger a woman starts menstruating and the older she starts menopause, the higher the risk of breast cancer. This is because the woman is exposed to hormones for a longer time. Hormones clearly play a role in developing breast cancer. Some hormones are produced by the ovaries.
Obesity is a risk factor in multiple cancers including breast cancer. Obese, postmenopausal women have at least twice the risk of breast cancer as their ideal weight peers. Estrogen (a hormone) is stored in body fat. The more body fat, the more estrogen in the body. It is thought that increased estrogen levels in obese, postmenopausal women may contribute to increased risk of developing breast cancer.
It’s heartening to note that regular moderate exercise (30 minutes, 3 times a week) has been shown to decrease the risk of breast cancer, independent of weight loss.