Breast cancer is the most common cancer among women, excluding skin cancers. The American Cancer Society estimates that in 1997 some 180,200 new cases of invasive breast cancer will be diagnosed among women in the United States. An estimated 1,400 cases will be diagnosed among men. Recently, the rate has leveled off at about 110 per 100,000. Most of this apparent increase is believed to be a result of marked increases in the use of mammography, providing better detection of early-stage breast cancers.
Breast cancer is the second leading cause of cancer death in women, exceeded only by lung cancer.
It is the leading cause of cancer death among women aged 40 to 55. The most recent data indicate that death rates have begun to decline in white women, and, for the first time, are also declining in younger African-American women. These decreases are attributed to earlier detection and improved treatment of breast cancer. Among women younger than 45 years of age, African-American women are more likely to develop breast cancer than white women. African-American women are more likely to die of breast cancer with a rate of 31.2 per 100,000 compared to white women with a rate of 26.0 per 100,000.