Breast Cancer Awareness

Printer-friendly versionSend by email

Worldwide, breast cancer comprises 10.4% of all cancer incidence among women, making it the second most common type of non-skin cancer (after lung cancer) and the fifth most common cause of cancer death. Breast cancer is about 100 times more common in women than in men, although males tend to have poorer outcomes due to delays in diagnosis. On January 1, 2007, in the United States there were approximately 2,591,855 women alive who had a history of cancer of the breast.

Incidence

The lifetime risk for breast cancer of women in the United States is usually given as 1 in 8 (12.5%) with a 1 in 35 (3%) chance of death.

Women's Probability of Developing Breast Cancer, US, 2003-2005
Birth to 39 40 to 59 60 to 69 70 and older Birth to Death
0.48 (1 in 208) 3.79 (1 in 26) 3.41 (1 in 29) 6.44 (1 in 16) 12.03 (1 in 8)

From 2003-2007, the median age at diagnosis for cancer of the breast was 61 years of age. Approximately 0.0% were diagnosed under age 20; 1.9% between 20 and 34; 10.5% between 35 and 44; 22.6% between 45 and 54; 24.1% between 55 and 64; 19.5% between 65 and 74; 15.8% between 75 and 84; and 5.6% 85+ years of age.

Survival & Stage

The overall 5-year relative survival for 1999-2006 from 17 SEER geographic areas was 89.0%. Five-year relative survival by race was: 90.2% for white women; 77.5% for black women.

Stage Distribution and 5-year Relative Survival by Stage at Diagnosis for
1999-2006, All Races, Females
Stage at Diagnosis Stage
Distribution (%)
5-year
Relative Survival (%)
Localized (confined to primary site) 60 98.0
Regional (spread to regional lymphnodes) 33 83.6
Distant (cancer has metastasized) 5 23.4
Unknown (unstaged) 2 57.9

Risk Factors

source from National Cancer Institute:

Studies have found the following risk factors for breast cancer:

  • Age: The chance of getting breast cancer increases as you get older. Most women are over 60 years old when they are diagnosed.
  • Personal health history: Having breast cancer in one breast increases your risk of getting cancer in your other breast. Also, having certain types of abnormal breast cells increases the risk of invasive breast cancer.
  • Family health history: Your risk of breast cancer is higher if your mother, father, sister, or daughter had breast cancer. The risk is even higher if your family member had breast cancer before age 50. Having other relatives (in either your mother's or father's family) with breast cancer or ovarian cancer may also increase your risk.
  • Certain genome changes: Changes in certain genes, substantially increase the risk of breast cancer. Tests can sometimes show the presence of these rare, specific gene changes in families with many women who have had breast cancer, and health care providers may suggest ways to try to reduce the risk of breast cancer or to improve the detection of this disease in women who have these genetic changes.
  • Radiation therapy to the chest: Women who had radiation therapy to the chest (including the breasts) before age 30 are at an increased risk of breast cancer. Studies show that the younger a woman was when she received radiation treatment, the higher her risk of breast cancer later in life.
  • Reproductive and menstrual history:
    • The older a woman is when she has her first child, the greater her chance of breast cancer.
    • Women who never had children are at an increased risk of breast cancer.
    • Women who had their first menstrual period before age 12 are at an increased risk of breast cancer.
    • Women who went through menopause after age 55 are at an increased risk of breast cancer.
    • Women who take menopausal hormone therapy for many years have an increased risk of breast cancer.
  • Race: In the United States, breast cancer is diagnosed more often in white women than in African American/black, Hispanic/Latina, Asian/Pacific Islander, or American Indian/Alaska Native women.
  • Breast density: Breasts appear on a mammogram (breast x-ray) as having areas of dense and fatty (not dense) tissue. Women whose mammograms show a larger area of dense tissue than the mammograms of women of the same age are at increased risk of breast cancer.
  • History of taking DES: DES was given to some pregnant women in the United States between about 1940 and 1971. (It is no longer given to pregnant women.) Women who took DES during pregnancy may have a slightly increased risk of breast cancer. The possible effects on their daughters are under study.
  • Being overweight or obese after menopause: The chance of getting breast cancer after menopause is higher in women who are overweight or obese.
  • Lack of physical activity: Women who are physically inactive throughout life may have an increased risk of breast cancer.
  • Drinking alcohol: Studies suggest that the more alcohol a woman drinks, the greater her risk of breast cancer.

Having a risk factor does not mean that a woman will get breast cancer. Most women who have risk factors never develop breast cancer.

For more information, please read the booklet by National Cancer Institute.

Posted by

Sui Zhang