|If you’ve been diagnosed with breast cancer, you will undergo a process known as staging to help determine how much the cancer has spread in your body. |
Breast cancer staging helps your doctor determine the best treatment options for you. By categorizing breast cancer, both doctor and patient are better able to predict the most likely outcome of the disease and make treatment decisions based, in part, on that prognosis.
|“The reason why we have very formal staging systems is to have a common language to compare new treatment and outcomes across studies and across countries,” says Christy Russell, MD, an associate professor of medicine at the Keck School of Medicine at the University of Southern California, chief of medicine at USC/Norris Cancer Hospital, co-director of the USC/Norris Breast Center, and a spokeswoman for the American Cancer Society. “When we do clinical trials, we require women all be of a certain stage so there’s a uniformity [among] the women.” |
How Breast Cancer Is Staged
Cancer spreads in the body through the lymph system and through the blood. To determine how far your breast cancer has spread, doctors will perform a series of tests that include:
Imaging. There are a number of special X-rays that may be used to get a better sense of the extent of your cancer, including mammography, ultrasound, bone scan, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, and positron emission tomography (PET) scan. Your doctor will determine the appropriate scans based on your condition.Sentinel node biopsy. Surgical removal of some of the lymph nodes closest to your tumor allows doctors to see whether the breast cancer has spread to these glands. Lymph node involvement usually indicates that the cancer will soon move to distant organs.CT-guided needle biopsy. CT scan images are used to help guide a needle directly into an area where cancer may have spread so that a tissue sample can be extracted. This sample is then examined under a microscope for cancerous cells. Breast Cancer Stages
The stages of breast cancer include:
Stage 0. Non-invasive breast cancer with no evidence that cancer cells have left the area in the breast where they initially formed. There are two subgroups of stage 0 breast cancer: ductal carcinoma in situ (DCIS) describes cancer cells found in the lining of a breast duct, and lobular carcinoma in situ (LCIS) represents abnormal cells found in the milk-producing tissues, or lobules, of the breast. DCIS can develop into invasive cancer, but LCIS rarely does. As a result, many doctors consider LCIS to be a risk factor for cancer rather than cancer itself. The five-year survival rate for stage 0 breast cancer is 100 percent.Stage I. Invasive breast cancer in which the tumor is small — measuring 2 centimeters or less — and no lymph nodes are involved. The five-year survival rate is 100 percent.Stage II. Invasive breast cancer in which the tumor is 5 cm or less and cancer may have spread to the lymph nodes. The five-year survival rate is between 81 and 92 percent.Stage III. Invasive breast cancer where the tumor is 5 cm or smaller and has definitely spread to nearby lymph nodes, or where the tumor is any size and has spread to the chest wall or the skin. The five-year survival rate is between 54 and 67 percent.Stage IV. Invasive breast cancer in which the cancer has spread to other organs, such as the lungs, liver, bone, or brain. The five-year survival rate is 20 percent. Even though a higher breast cancer stage tends to mean a worse prognosis, “stage is not the only piece of the puzzle in terms of understanding the risk of the cancer coming back and what therapy [can be] offered,” Dr. Russell says. No matter what stage your breast cancer is at the time of diagnosis, you and your doctor can work together to develop the best breast cancer treatment plan that is tailored to you.
By Dennis Thompson Jr.