Breast cancer is the most common cancer among American women, except for skin cancers. About 1 in 8 (12 percent) women in the U.S. will develop invasive breast cancer during their lifetime. Breast cancer is a malignant tumor that starts in the cells of the breast. A malignant tumor is a group of cancer cells that can grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body. The disease occurs almost entirely in women, but men can get it, too.
Most breast cancers begin in the cells that line the ducts (ductal cancers). Some begin in the cells that line the lobules (lobular cancers), while a small number start in other tissues.
The American Cancer Society's estimates for breast cancer in the U.S. for 2014 are:
After increasing for more than two decades, female breast cancer incidence rates began decreasing in 2000, then dropped by about 7 percent from 2002 to 2003. This large decrease was thought to be due to the decline in use of hormone therapy after menopause that occurred after the results of the Women's Health Initiative were published in 2002. This study 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 breast cancer will be responsible for a woman's death is about 1 in 36 (about 3 percent).
The good news: Death rates from breast cancer have been declining since about 1989, 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. Right now, there are more than 2.8 million breast-cancer survivors in the U.S. This includes women still being treated and those who have completed treatment.
Clearly, early screening is important, and you can help take charge of your health by talking with your doctor about screening and breast self-exam.
Source: American Cancer Society