14, Oct 2026
Breast cancer is a disease process in which cells in the breast form a tumor. The type of breast cells where the cancer begins determines the specific type of breast cancer.
Breast cancer can develop in various areas of the breast, including the milk ducts or milk-producing glands.
The two most common types of breast cancer are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC).
IDC begins in the milk ducts and extends beyond them into nearby breast tissue. ILC begins in the lobules, where milk is produced, and spreads into the surrounding breast tissue. Cancer cells can also spread to different parts of the body through the lymph nodes and blood vessels. This process is called metastasis.
Some risk factors of breast cancer are related to personal behaviors and reproductive or hormonal choices. These factors may include diet, physical activity, having children, breastfeeding, and the use of certain hormone medications.
Alcohol consumption may also increase the risk of breast cancer. Having excess body weight after menopause can increase breast cancer risk. Lack of regular physical activity, particularly after menopause, may increase risk.
Women with no children or women who had their first child after age 30 have a slightly increased risk of breast cancer. Women who do not breastfeed may have a slightly increased risk of breast cancer. Some forms of hormonal birth control and certain types of hormone therapy used during menopause may increase breast cancer risk.
Age, genetics, and certain personal or family medical histories contribute to the risk factor of breast cancer. Breast cancer occurs primarily in women, although men can also develop breast cancer.
The risk of breast cancer also generally increases with age. Approximately 5%–10% of breast cancer cases are thought to be hereditary and may be linked to inherited gene changes. Having a close family member with breast cancer can increase a person's risk.
Overall, Caucasian women have a slightly higher incidence of breast cancer than African American women, although risk patterns vary by age and breast cancer subtype.
Greater adult height is associated with a slightly increased risk of breast cancer. Dense breast tissue can increase breast cancer risk and can also make breast abnormalities more difficult to detect on a mammogram.
Beginning menstruation at a younger age can slightly increase breast cancer risk. Experiencing menopause at an older age can slightly increase breast cancer risk because of longer lifetime exposure to estrogen and other hormones.
If you notice a new lump in your breast, breast pain, or any other changes in your breast or nipple, contact your doctor immediately for an evaluation. Women starting at age 40 should get checked routinely for breast cancer every 1 or 2 years, even when they aren't experiencing any symptoms.
Regular breast cancer screening is also important, even if you do not have symptoms. Screening recommendations can vary based on age, personal risk factors, and family history.
Other possible signs of breast cancer include breast swelling, skin dimpling, nipple retraction, where the nipple may turn inward or become newly inverted. The skin may become red, dry, flaky, scaly, or thicker than usual. Fluid may come from the nipple, particularly discharge that occurs without squeezing the nipple or that is bloody. Lymph nodes under the arm or near the collarbone may become enlarged.
Several types of tests can help detect breast cancer, including clinical breast exams, mammograms, breast ultrasound, and breast MRI. Thermography is sometimes offered, but it is not a recommended substitute for standard breast cancer screening.
Mammography remains the primary screening tool to detect breast cancer before symptoms appear. If your mammogram shows an abnormal area that needs further evaluation, your doctor may order additional tests to get a better view of the breast tissue. These may include additional mammogram images, a breast ultrasound, or other imaging tests.
If you carry certain breast cancer risk factors, your doctor may recommend genetic testing to have a better understanding of your risks, starting mammography at a younger age, having screening more frequently, or using additional imaging such as breast MRI. Talk with your doctor about which screening approach is appropriate for you.
If the area continues to appear abnormal, your provider may recommend a biopsy, in which a sample of breast tissue is removed and examined under a microscope. A biopsy is the only way to confirm whether breast cancer is present and, if so, determine the type of breast cancer.
It is important to remember that breast lumps and changes seen on a mammogram are relatively common and do not always mean that you have cancer. Benign, or noncancerous, conditions cause many abnormal findings.
October marks Breast Cancer Awareness Month, which aims to raise awareness about breast cancer and its impact on individuals and to encourage education, regular screening, early detection, and conversations about breast health.
Dr. Sue Mitra and her staff strive to offer their patients the best care, advice and services available in the medical field with the goal to keep patient healthy & happy.
Dr. Sue Mitra is board certified in international medicine. She is seen here with a Cologuard, which is a noninvasive colon cancer screening test. (Photo by: Tim Shortt/Florida Today)