health

Breast cancer is one of the most common cancers in women, affecting
one in every eight women in the United States in the course of her lifetime.
According to the American Cancer Society, there are about

68,000 cases of carcinoma in situ (noninvasiveor stage 0 breast cancer)
in the United States each year, and 183,000 cases of invasive breast
cancer (stages I through IV). About 2,000 American men will be
diagnosed with breast cancer. Breast cancer is the second leading cause
of death from cancer among women in the United States; only lung cancer
is deadlier.

About 41,000 American women and 450 men die each year from breast
cancer. The death rate has decreased in recent years, largely as a
result of earlier detection. There were an estimated 2.5 million survivors
of breast cancer in the United States as of 2008.

Risk factors for breast cancer include:

• Sex. The female/male ratio for breast
  cancer is 99:1.
• Age. Two out of three invasive breast cancers
  are found in women over fifty-five.
• Genetic mutations. Between 5 and 10 percent
  of breast cancers are thought to be
  caused by inherited mutations in two
  genes known as BRCA1 and BRCA2. Women with either of
  these mutations have an 80 percent chance of developing breast
  cancer in their lifetime.
• Family history of breast cancer. A woman who has a mother, sister,
  or daughter with breast cancer has double the risk of developing
  breast cancer herself.
• Race. Caucasian women are slightly more likely to develop breast
  cancer than women of other races; however, breast cancers in
  African American women are often more aggressive. The reason
  for this difference is not known.
• Early menstruation (before age twelve) or late menopause (after
  age fifty-five).
• First pregnancy after age thirty or no pregnancy.
• Obesity.
• Smoking.