Breast Cancer Staging and Lymph Node Involvement
If your biopsy comes back positive for breast cancer, your Rocky Mountain Cancer Centers (RMCC) oncology team will need to learn the extent (stage) of the disease in order to help you choose the best treatment. The stage is based on various factors including the size of the cancer, whether the cancer has invaded nearby tissues, and whether the cancer has spread (metastasized) to other parts of the body.
To stage your breast cancer, we may use blood tests and other tests, such as:
- Bone Scan. To perform a bone scan, we will inject a small amount of a radioactive substance into a blood vessel. This substance travels through the bloodstream and collects in the bones. A machine called a scanner will then detect and measure the radiation, as well as take pictures to determine if any cancer has spread to the bones.
- CT Scan. CT scans are sometimes used to look for breast cancer that has spread to the liver or lungs. During a CT scan, an x-ray machine linked to a computer takes a series of detailed pictures of your chest or abdomen. To make abnormal areas easier to see, you may receive contrast material by injection into a blood vessel in your arm or hand.
- Lymph Node Biopsy. Many times, the stage isn’t known until after the tumor in your breast and one or more lymph nodes under your arm have been surgically removed. Surgeons use a method called sentinel lymph node biopsy to remove the lymph node most likely to have breast cancer cells. During this procedure, your surgeon will inject a blue dye, a radioactive substance, or both near the breast tumor–or in some cases, under the nipple. Then, your surgeon will use a scanner to find the sentinel lymph node containing the radioactive substance or look for the lymph node stained with dye. The sentinel node is removed and checked for cancer cells. Cancer cells may appear first in the sentinel node before spreading to other lymph nodes and other places in the body.
It’s understandable that you may feel nervous about these tests, however, they are a necessary part of the process. And, rest assured, we will do our best to make you feel comfortable. These tests allow your RMCC oncology team to see whether the cancer has spread and, if so, to what parts of your body. When breast cancer spreads, cancer cells are often found in lymph nodes under the arm (axillary lymph nodes). Breast cancer can also spread to almost any other part of the body, such as the bones, lungs, liver, and brain.
It’s important to understand that when breast cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary (original) tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. Therefore, the disease is metastatic breast cancer, not bone cancer. For that reason, it is treated as breast cancer, not bone cancer. This new tumor is typically referred to as “distant” or metastatic disease.
Breast Cancer Stages
To understand how your RMCC oncologist determines the stage of your cancer, it’s helpful to know a little about something called the TNM system. The TNM staging system is a classification system developed by the American Joint Committee on Cancer for describing the extent of disease progression in cancer patients.
TNM stands for:
- T = Tumor size
- N = Lymph Node status (the number and location of lymph nodes with cancer)
- M = Metastases (whether or not the cancer has spread to other parts of the body)
Any diagnosis of any stage of breast cancer can leave you feeling fearful and overwhelmed. However, understand your cancer and knowing what to expect can help you and your loved ones feel more in control and cope with your diagnosis.
Breast cancer stage is usually expressed as a number on a scale of 0 through IV — with stage 0 describing non-invasive cancers that remain within their original location and stage IV describing invasive cancers that have spread outside the breast to other parts of the body.
The stages of breast cancer are as follows:
Stage 0 is sometimes used to describe abnormal cells that are not invasive cancer. For example, Stage 0 is used for ductal carcinoma in situ (DCIS). DCIS is diagnosed when abnormal cells are in the lining of a breast duct, but the abnormal cells have not invaded nearby breast tissue or spread outside the duct. Although many doctors don’t consider DCIS to be cancer, DCIS sometimes becomes invasive breast cancer if not treated.
Stage I is an early stage of invasive breast cancer. Cancer cells have invaded breast tissue beyond where the cancer started, but the cells have not spread beyond the breast. The tumor is no more than 2 centimeters (three-quarters of an inch) across.
Stage II is one of the following:
- The tumor is no more than 2 centimeters (three-quarters of an inch) across. The cancer has spread to the lymph nodes under the arm.
- The tumor is between 2 and 5 centimeters (three-quarters of an inch to 2 inches). The cancer has not spread to the lymph nodes under the arm.
- The tumor is between 2 and 5 centimeters (three-quarters of an inch to 2 inches). The cancer has spread to the lymph nodes under the arm.
- The tumor is larger than 5 centimeters (2 inches). The cancer has not spread to the lymph nodes under the arm.
Stage III is locally advanced cancer. It is divided into Stage IIIA, IIIB, and IIIC.
- Stage IIIA is one of the following:
- The tumor is no more than 5 centimeters (2 inches) across. The cancer has spread to underarm lymph nodes that are attached to each other or to other structures. Or the cancer may have spread to lymph nodes behind the breastbone.
- The tumor is more than 5 centimeters across. The cancer has spread to underarm lymph nodes that are either alone or attached to each other or to other structures. Or the cancer may have spread to lymph nodes behind the breastbone.
- Stage IIIB is a tumor of any size that has grown into the chest wall or the skin of the breast. It may be associated with swelling of the breast or with nodules (lumps) in the breast skin:
- The cancer may have spread to lymph nodes under the arm.
- The cancer may have spread to underarm lymph nodes that are attached to each other or other structures. Or the cancer may have spread to lymph nodes behind the breastbone.
- Inflammatory breast cancer is a rare type of breast cancer. The breast looks red and swollen because cancer cells block the lymph vessels in the skin of the breast. When a doctor diagnoses inflammatory breast cancer, it is at least Stage IIIB, but it could be more advanced.
- Stage IIIC is a tumor of any size. It has spread in one of the following ways:
- The cancer has spread to the lymph nodes behind the breastbone and under the arm.
- The cancer has spread to the lymph nodes above or below the collarbone.
Stage IV is distant metastatic cancer. The cancer has spread to other parts of the body, such as the bones or liver.
Recurrent Breast Cancer
Unfortunately, there are times when a patient’s cancer returns after being seemingly destroyed by treatment. This is called recurrent cancer. Recurrent cancers typically happen because undetected cancer cells remained somewhere in your body after treatment. Your breast cancer may return in the breast or chest wall. Or, it may return in any other part of the body, such as the bones, lungs, liver, or brain.
The Role of Lymph Nodes in Breast Cancer
One of the first places breast cancer can spread and grow is in nearby lymph nodes, which are part of the body’s lymphatic (lymph) system. Your immune system— the body’s defense against infection and disease— relies quite a bit on the lymphatic system, which is made up of three parts:
- Lymph, a clear fluid that circulates through the lymphatic system
- Lymphatic vessels
- Lymph nodes
The primary function of the lymph system is to circulate the lymph, which contains infection-fighting white blood cells, throughout the body and to flush your body of toxins, waste, and other unwanted materials.
As breast cancer cells multiply, they can enter the lymphatic vessels that are located in a woman’s breast tissue. The lymph fluid then carries the cells throughout the body. Often times, the lymph nodes in the underarm area are the first place breast cancer will start to grow since they are the closest to the breast.
The tests used by your Rocky Mountain Cancer Centers oncologist to determine that there are breast cancer cells in the lymph nodes is called lymph node evaluation.
Determining Lymph Node Involvement
To determine if lymph nodes are involved in your breast cancer, your surgeon will remove one or several underarm lymph nodes (at the time of the tumor removal) so they can be biopsied and then examined under a microscope.
Lymph nodes can be checked in two different ways. The most common and least-invasive method is called sentinel lymph node biopsy. The other is called axillary lymph node dissection.
In most cases, lymph node surgery is done as part of the main surgery to remove the breast cancer. There are times, however, it may be done as a separate operation.
Sentinel Lymph Node Biopsy (SLNB)
A sentinel lymph node is defined as the first lymph node to which cancer cells are most likely to spread from a primary tumor. There are times when more than one sentinel lymph node is present.
During surgery to remove early-stage breast cancer, the sentinel node is identified and then removed so it can be sent to a pathologist, who is a physician that studies the causes and effects of diseases. The pathologist will determine if there is cancer in it. This procedure to remove the sentinel lymph node so it can be examined is called a sentinel lymph node biopsy (SLNB).
To identify the sentinel node your breast cancer surgeon will:
- Inject a radioactive substance, blue dye, or both near the tumor
- Use a device that detects radioactivity to find the sentinel node or looks for lymph nodes that are stained with the blue dye
- Make a small incision (about 1/2 inch) in the overlying skin and remove the node once it has been located
The results of the pathology exam help determine breast cancer stage and help plan treatment.
If no cancer is found in the sentinel nodes (lymph node-negative), surgery to remove more lymph nodes will not be needed because it is unlikely other lymph nodes have cancer. If cancer is found in the sentinel nodes (lymph node-positive), however, more lymph nodes may be removed with a procedure called axillary dissection.
Axillary Lymph Node Dissection (ALND)
Axillary lymph nodes run from your breast tissue down into the armpit. This area under the arm is called the axilla.
During an axillary lymph node dissection, anywhere from 10 to 40 lymph nodes are removed and examined. These nodes are typically removed during your lumpectomy or mastectomy.
Lymph Node Status and Breast Cancer Treatment
After the tissue from your biopsy has been examined, your Rocky Mountain Cancer Centers’ oncologist will go over the results (called a pathology report). The pathology report will show how many lymph nodes were removed and how many were “involved” (tested positive for cancer). This is referred to as lymph node status.
Breast cancer that has not spread to nearby lymph nodes, is referred to as node-negative status. If the report indicates that cancer is present in the lymph nodes, this is referred to as node-positive status. Positive results also mean that the cancer may have already or could possibly spread to other organs, such as the bones, lungs, liver, and brain. In order to determine that, your RMCC oncology team would need to conduct further tests.
The pathology report will also show how much cancer is in each node. Cancer cells can range from small in size and few in number to large in size and many in number. This information may be reported as:
- Microscopic (or minimal), meaning only a few cancer cells are in the node and that a microscope is needed to find them.
- Gross (also called significant or macroscopic), meaning there is a lot of cancer in the node and that it can be seen or felt without the use of a microscope.
- Extracapsular extension, meaning the cancer has spread (metastasized) outside the wall of the node.
Breast cancer treatment decisions and prognosis (outlook) can be affected by lymph node status. It’s important to remember, however, that life expectancy and treatments are improving all the time. If there is cancer found in the lymph nodes, your breast cancer specialist might recommend chemotherapy in addition to surgery, since chemotherapy can attack cancer cells throughout the lymph system.
Early detection is key. This is why we highly recommend you perform self-exams at home and schedule regular mammograms. If you have any concerns about your breast health be sure to talk with your primary care physician or your gynecologist. The earlier breast cancer is found, the less chance there is of it spreading to the lymph nodes.