Breast cancer is the most common cancer among American women, except for skin cancers. About 1 in 8 (12%) women in the US will develop invasive breast cancer during their lifetime.
Breast cancer is the development of cancer from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, fluid coming from the nipple, or a red scaly patch of skin. In those with distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin.
After increasing for more than 2 decades, female breast cancer incidence rates began decreasing in 2000. One theory for the recent large decrease was thought to be due to the decline in use of hormone therapy after menopause. A study in 2002 linked the use of hormone therapy to an increased risk of breast cancer and heart diseases. Incidence rates have been stable in recent years.
Breast cancer is the second leading cause of cancer death in women, exceeded only by lung cancer. The chance that a woman will die from breast cancer is about 1 in 36. Death rates from breast cancer have been declining, with larger decreases in women younger than 50. These decreases are believed to be the result of earlier detection through screening and increased awareness, as well as improved treatment.