Breast Cancer

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What Is Breast Cancer? TOPICS

What are the key statistics about breast cancer?

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.

The American Cancer Society's estimates for breast cancer in the United States for 2014 are:

  • About 232,670 new cases of invasive breast cancer will be diagnosed in women.
  • About 62,570 new cases of carcinoma in situ (CIS) will be diagnosed (CIS is non-invasive and is the earliest form of breast cancer).
  • About 40,000 women will die from breast cancer

After increasing for more than 2 decades, female breast cancer incidence rates began decreasing in 2000, then dropped by about 7% 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%). 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.

At this time there are more than 2.8 million breast cancer survivors in the United States. (This includes women still being treated and those who have completed treatment.) Survival rates are discussed in the section “How is breast cancer staged?


Last Medical Review: 09/11/2013
Last Revised: 01/31/2014