The Role of Lymph Nodes in Breast Cancer
One of the first places that breast cancer is likely to spread is into your lymph nodes. Once cancer cells have entered the lymph nodes there is a high likelihood they’ve also spread throughout the body. This is because the lymph fluid circulates through your body to carry away waste, but can also allow cancer cells to spread throughout the body.
Understanding lymph node involvement will impact the most likely impact the types of breast cancer treatment needed. For those patients whose lymph nodes are affected, chemotherapy is usually given.
How to Determine If Breast Cancer Has Spread to Lymph Nodes
After a breast cancer diagnosis, your oncologist is going to determine several things about the type of breast cancer, stage of the cancer and hormone involvement. Determining if the cancer has spread to lymph nodes is part of the staging process.
Most often during surgery to remove the tumor the breast cancer surgeon will also remove some lymph nodes. These will be biopsied to determine if cancer cells are present inside of them.
To gather the lymph nodes, the surgeon will commonly perform a sentinel lymph node biopsy. This is the less invasive of the types of lymph node biopsies and preferred by many breast cancer surgeons.
Sentinel Lymph Node Biopsy
The breast cancer surgeon will inject a radioactive dye close to the tumor. The lymphatic vessels will carry the substance along the same path that the cancer would likely take. The first lymph node(s) the dye or radioactive substance travels to will be the sentinel nodes(s).
Once the surgeon identifies the sentinel node, that lymph node and several nearby will be removed and sent to a pathologist to determine whether there are cancer cells in the lymph nodes.
Axillary Lymph Node Dissection
The other type of lymph node biopsy is called an axillary lymph node dissection. In an axillary lymph node dissection procedure, or shortened as ALND, the surgeon removes between 10 and 40 lymph nodes from your axilla (area under your arm) to be checked for cancer. The surgeon typically performs ALND after a sentinel node biopsy or as part of a breast cancer surgery.
You may require ALND if:
- A past SLNB shows three or more of your underarm lymph nodes are infected with cancer cells.
- Your breast cancer specialist can feel swollen lymph nodes under your collarbone or underarm, or if they see them on imaging tests and a core needle or FNA biopsy shows cancer.
- The cancer has become big enough it extends outside your lymph node(s).
- If you have already received chemotherapy before surgery and the sentinel node(s) is positive for cancer.
The American Cancer Society indicates that ALND may be skipped for:
- Women with 2 inch (5 cm) tumors or smaller who have fewer than three positive sentinel lymph nodes and are undergoing a breast-conserving procedure and then radiation.
- Women who will have radiation and have already had a mastectomy.
How Lymph Node Status Affects Treatment for Breast Cancer
If the results of the lymph node biopsy is lymph node-negative, meaning no cancer in the sentinel nodes, it's unlikely other lymph nodes will have cancer. And depending on the size and location of the tumor, chemotherapy may not be needed.
If the results are lymph node-positive, meaning cancer is found in the sentinel node, they may need to remove more lymph nodes with an axillary dissection procedure. Patients who have lymph node involvement will typically require chemotherapy to kill cancer cells that could be traveling through the body by way of the lymph fluid.
Because every patient is different, talk to your Cancer Care Centers of Brevard breast cancer specialist about whether you have lymph node involvement and what treatments are needed to give you the best possible prognosis.