Breast cancer is the most common cancer among women, except for nonmelanoma skin cancers. The chance of developing invasive breast cancer at some time in a woman’s life is about 1 in 7 (13.4%). It is estimated that in 2004 about 215,990 new cases of invasive breast cancer will be diagnosed among women in the United States. At this time there are slightly over 2 million women living in the U.S. who have been diagnosed with and treated for breast cancer.

Carcinoma in situ (CIS) accounts for about 59,390 new cases each year. CIS is noninvasive and is the earliest form of breast cancer. Breast cancer also occurs in men. An estimated 1,450 cases will be diagnosed in men in 2004.

Breast cancer incidence rates have continued to increase since 1980, although the rate of increase slowed in the 1990s, compared to the 1980s. Furthermore, in the more recent time period (1987-2000), breast cancer incidence rates have increased only in those aged 50 and older.

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 33 (3%). In 2004, about 40,110 women and 470 men will die from breast cancer in the United States. Death rates from breast cancer have been declining. These decreases are believed to be the result of earlier detection and improved treatment.

Revised 9/04