Breast cancer is the most common cancer occurring in American women today. The American Cancer Society reports that one out of every eight women in the United States will develop breast cancer in her lifetime. Understanding the stage of the cancer will help provide information about prognosis and will also allow for an informed decision about the best treatment options.
Breast Cancer Stages
Once the diagnosis of breast cancer has been made, the stage of the breast cancer is determined to aid in making treatment decisions. Staging is determined by the size of the tumor, local extension to the chest wall or skin, the number and location of lymph nodes involved, and whether there are metastases in other areas of the body. To provide a more precise and standardized approach to staging, the TNM system has been developed: T stands for tumor size, N stands for nodal spread, and M stands for distant metastases. Stage 0 breast cancer represents ductal carcinoma in situ (DCIS), which means that the cancer is contained within the ducts. Once the cancer has become invasive, the cancer is designated as Stage I-IV. This system of staging was devised by the American Joint Commission on Cancer and is shown below:
Prognosis of Breast Cancer
The outcome, or prognosis, for a woman with breast cancer is related to the extent or spread of the disease at the time of diagnosis. The larger the tumor size and the higher the number of lymph nodes with cancer, the poorer the outcomes. In contrast, women with Stage 0 or Stage I breast cancer have a 10-year survival of well over 90%. This is why it is so important to diagnose breast cancer early, and the best way to do that is by beginning mammograms at age 40 and yearly thereafter.