There are many potential causes of breast cancer, and in most cases, the exact cause of a particular breast cancer is not known. However, there are certain risk factors that have been identified that can increase a person’s likelihood of developing the disease. Some of the main risk factors for breast cancer include:
- Gender: Breast cancer is much more common in women than in men.
- Getting older. The risk for breast cancer increases with age. Most breast cancers are diagnosed after age 50.
- Genetic mutations. Women who have inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2, are at higher risk of breast and ovarian cancer.
- Reproductive history. Starting menstrual periods before age 12 and starting menopause after age 55 expose women to hormones longer, raising their risk of getting breast cancer. Women who have never given birth also have a slightly higher risk of breast cancer.
- Having dense breasts. Dense breasts have more connective tissue than fatty tissue, which can sometimes make it hard to see tumors on a mammogram. Women with dense breasts are more likely to get breast cancer.
- Personal history of breast cancer or certain non-cancerous breast diseases. Women who have had breast cancer are more likely to get breast cancer a second time. Some non-cancerous breast diseases such as atypical hyperplasia or lobular carcinoma in situ are associated with a higher risk of getting breast cancer.
- Family history of breast or ovarian cancer. A woman’s risk for breast cancer is higher if she has a mother, sister, or daughter (first-degree relative) or multiple family members on either her mother’s or father’s side of the family who have had breast or ovarian cancer. Having a first-degree male relative with breast cancer also raises a woman’s risk.
- Previous treatment using radiation therapy. Women who had radiation therapy to the chest or breasts (for instance, treatment of Hodgkin’s lymphoma) before age 30 have a higher risk of getting breast cancer later in life.
- Exposure to the drug diethylstilbestrol (DES). DES was given to some pregnant women in the United States between 1940 and 1971 to prevent miscarriage. Women who took DES, or whose mothers took DES while pregnant with them, have a higher risk of getting breast cancer.
- Hormone replacement therapy (HRT): Women who take HRT for a prolonged period of time may have a higher risk of breast cancer. Some studies have suggested that prolonged exposure to estrogen through certain hormonal therapies or through certain lifestyle factors such as diet, may increase the risk of breast cancer.
- Drinking alcohol: Consuming alcohol has been linked to an increased risk of breast cancer.
- Obesity: Being overweight or obese has been linked to an increased risk of breast cancer, particularly after menopause.
It’s also important to note that many women with these risk factors do not develop breast cancer, and conversely, some women who do develop the disease have no known risk factors.
Regular screening and early detection, as well as limiting exposure to known risks like alcohol, is crucial for the fight against breast cancer.