Breast cancer is the second most commonly diagnosed cancer and the second leading cause of cancer deaths among women in the United States.1 In 2009, more than 192,000 American women will be diagnosed and more than 40,000 Americans will die from the disease.1 There are approximately 2.5 million breast cancer survivors in the United States.9
Breast cancer is the uncontrolled growth of cancerous cells that originate in breast tissue. In advanced breast cancer, the cancer has spread (metastasized) to other parts of the body, most commonly the lungs, bones, liver and brain.2 While the causes are unknown, there are many forms of breast cancer based in part on genetic characteristics, such as human epidermal growth factor receptor-2 (HER2)-positive and HER2-negative. Each form of breast cancer has a different prognosis. The American Society of Clinical Oncology recommends that all women diagnosed with breast cancer have tumor marker tests, which can help predict how a tumor may behave and help determine the best treatment options.3
|Stage||Description||5-Year Survival Rate7|
|I||Tumor is only in the breast and < 2 centimeters (cm)||100%|
|II||Tumor has spread to lymph nodes in the breast and < 5 cm||86%|
|III||Tumor has spread to 4-9 lymph nodes or to the chest wall or skin||57%|
|IV||Tumor has spread to distant organs||20%|
1 American Cancer Society. Cancer Facts and Figures 2009. Accessed May 5, 2009.
2 National Cancer Institute. Metastatic Cancer: Questions and Answers. Accessed January 9, 2008.
3 American Society of Clinical Oncology. What to Know: ASCO's Guideline on Tumor Markers for Breast Cancer. Comprehensive Cancer Network. Clinical Practice Guidelines in Oncology V.2.2007.
4 BreastCancer.org. Will Herceptin Work for You? Accessed January 9, 2008.
5 BreastCancer.org. How Herceptin Works. Accessed January 9, 2008.
7 American Cancer Society. How is Breast Cancer Staged. Accessed March 23, 2009.
8 Press MF, Bernstein L, Thomas PA, et al. HER-2/neu gene amplification characterized by fluorescence in situ hybridization: poor prognosis in node-negative breast carcinomas. J Clin Oncol. 1997;15:2894-2904.
9 American Cancer Society. What are the Key Statistics for Breast Cancer? Accessed March 25, 2009.
11 American Cancer Society. African Americans More Likely to Die from Breast Cancer. Accessed on March 30, 2009.