Breast Cancer
Breast cancer accounts for 23% of all new cancer
cases in females and 14% of all cancer deaths in females, making it
the leading cause of cancer and cancer mortality among females worldwide.364 Worldwide,
more than 1.5 million females were diagnosed with breast cancer in
2002, and more than 411,000 females are expected to die from it annually.364 The
incidence of breast cancer varies considerably among populations,
with the highest rates found in North America (99.4 cases per
Risk Factors
Outside of gender, the most important risk factor for the development of breast cancer is age.359 A number of other factors also increase the relative risk of breast cancer.359 These include a personal or family history of breast cancer, presence of biopsy-confirmed benign breast disease, irradiation of the chest, or high breast-tissue density.359 Several reproductive factors, such as early menarche, late menopause, first pregnancy after the age of 30, or having no children at all, may increase the risk of breast cancer, theoretically due to extended estrogen exposure.382 Use of oral contraceptives, hormone replacement therapy, physical inactivity, obesity after menopause, and excessive alcohol intake can also increase the risk of breast cancer.359 Finally, specific mutations in 2 breast cancer susceptibility genes (BRCA1 and BRCA2) have been associated with familial breast cancer.359, 382, 383
Screening
Breast self-exam, mammography, and clinical breast exam are useful tools in the early detection of breast cancer.382 Breast cancer is usually detected in its early stages by mammography, which shows breast abnormalities before symptoms present. Mammography is effective in detecting 80%–90% of breast cancers that are not yet symptomatic.359 Regular mammography and clinical breast exams may reduce mortality by 25%–30% in females over 50 years of age.382 According to the American Cancer Society, all females 40 years of age or older should have an annual mammogram and clinical breast exam.359
Treatment Options and Survival Rates
Treatment varies based on tumor size, stage, and patient preference, among other considerations. Options include lumpectomy, mastectomy with some axillary lymph node removal, radiation, chemotherapy, hormone therapy, and/or biologic therapy, either singularly or in combination. Despite the high incidence and mortality numbers, the overall prognosis for patients is good. The 5-year survival rates for localized, regional, and metastasized breast cancers are 98%, 83%, and 26%, respectively.359
Content on this page was last reviewed on January 31, 2010.
Content on this page was last changed on January 12, 2010.
References:| 359. | American Cancer Society. Cancer facts & figures 2007. American Cancer Society website. http://www.cancer.org/downloads/STT/CAFF2007PWSecured.pdf. Accessed February 5, 2007. |
| 364. | Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin. 2005;55(2):74-108. |
| 382. | Davidson NE. Breast cancer. In: Dale DC, Federman DD, eds. ACP Medicine Online. Based on: Dale DC, Federman DD, eds. ACP Medicine. New York, NY: WebMD Professional Publishing; 2004. http://www.acpmedicine.com. Accessed June 29, 2007. |
| 383. | Collins FS. BRCA — lots of mutations, lots of dilemmas. N Engl J Med. 1996;334(3):186-188. |
| 8008. | American Cancer Society. Cancer facts and figures 2008. American Cancer Society website. http://www.cancer.org/downloads/STT/2008CAFFfinalsecured.pdf . Accessed April 2, 2008. |
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