Breast Cancer

Breast cancer is cancer arising in breast tissue. Cancer is simply a group of abnormal cells that have abnormal growth patterns.
Although breast cancer is primarily a disease of women, almost 1% of breast cancers occur in men. In 2007, it is estimated that 2,030 men in the U.S. will develop invasive breast cancer.
Breast cancer is the most common type of cancer in women with the exception of nonmelanoma skin cancers. It is the second leading cause of death by cancer in women, following only lung cancer.
In 2007, the American Cancer Society estimated that 178,480 new cases of invasive breast cancer would be diagnosed among women in the United States, and that a further 62,030 new cases of in-situ (noninvasive) breast cancer would be diagnosed.
A woman has a lifetime risk of developing invasive breast cancer of about one in eight, or 13%.
Death rates from breast cancer have been gradually declining and continue to decline. These decreases are likely due both to increased awareness and screening and improved treatment methods.
Breast Cancer Causes
Many women who develop breast cancer have no risk factors other than age and sex.
Gender is the biggest risk because breast cancer occurs mostly in women.
Age is another critical factor. Breast cancer may occur at any age, though the risk of breast cancer increases with age. The average woman at age 30 years has one chance in 280 of developing breast cancer in the next 10 years. This chance increases to one in 70 for a woman aged 40 years, and to one in 40 at age 50 years. A 60-year-old woman has a one in 30 chance of developing breast cancer in the next 10 years.
White women are slightly more likely to develop breast cancer than African American women in the U.S.
A woman with a personal history of cancer in one breast has a three- to fourfold greater risk of developing a new cancer in the other breast or in another part of the same breast. This refers to the risk for developing a new tumor and not a recurrence (return) of the first cancer.
Breast Cancer Symptoms
Early breast cancer has no symptoms. It is usually not painful.
Most breast cancer is discovered before symptoms are present, either by finding an abnormality on mammography or feeling a breast lump. A lump in the armpit or above the collarbone that does not go away may be a sign of cancer. Other possible symptoms are breast discharge, nipple inversion, or changes in the skin overlying the breast.
Most breast lumps are not cancerous. All breast lumps, however, need to be evaluated by a doctor.
Breast discharge is a common problem and is rarely a symptom of cancer. Discharge is most concerning if it is from only one breast or if it is bloody. In any case, all breast discharge should be evaluated.