Breast cancer is a malignant tumor that has developed from cells in the breast. An invasive tumor is a group of cancer cells that may invade surrounding tissues or spread to other areas of the body. Breast cancer is the second most common cancer diagnosed in women in the United States with nearly 250,000 new cases each year. Advances in research to understand, detect, and treat breast cancer in recent years are associated with a decrease in the rate of deaths from the disease.

Abnormal changes in the breast may be signs of breast cancer. Some changes are visible just by looking, while most occur below the surface of the skin. A lump within a breast that persists beyond the monthly cycle is considered suspicious and should be examined by a health professional. Skilled self exams can help women learn the normal look and feel of their breasts so that they can detect a suspicious tumor when it is small. A clinician may notice a suspicious lump during a clinical breast examination. Lumps and changes underneath the surface of the skin can be distinguished from normal breast structures by fingers that have been trained using the MammaCare Method. Any unusual changes in the skin or within the breast should be brought to a health care provider, even if a recent mammogram was normal. Visual changes might include redness, swelling, changes in the shape or contour of the breast (e.g. puckering, dimpling), large or pronounced vein changes, and excessive or bloody nipple discharge.

Although there is no known cause of breast cancer, certain risk factors have been identified. The most significant risk factors for breast cancer are gender and age. Women are at greater risk for developing breast cancer than are men because women have many more breast cells than men. Additionally, a woman’s risk of developing breast cancer increases with age.

Some risk factors cannot be changed, such as genetics and family history. Having a first-degree relative (e.g., mother, sister, daughter) with breast cancer can almost double a woman’s risk. Women who carry BRCA1 or BRCA2 genes have up to an 85 percent chance of developing breast cancer during their lifetimes, though genetic factors account for only 5 to 10 percent of breast cancer cases. Other risk factors that cannot be changed include dense breast tissue, race and ethnicity, personal history of breast cancer, and certain benign breast conditions.

Women can take steps to reduce their risk by modifying certain lifestyle behaviors such as limiting alcohol use and increasing physical activity. There are many factors with uncertain, controversial, or unproven effect on breast cancer risk including the use of antiperspirants, chemicals in the environment, bras, and tobacco smoke. Women should speak with their health care providers about assessing risk for developing breast cancer and taking steps toward a healthy lifestyle to reduce risk wherever possible.