Cancerous lymph nodes are frequently removed as part of cancer treatment. Lymph nodes are small, bean-shaped organs that function as filters in the body’s lymphatic system, a network of vessels and tissues that manages fluid levels and fights infection. When cancer cells break away from the original tumor, they often travel through this system, making the lymph nodes the most common first site of spread, known as metastasis. Finding cancer in these nodes indicates that the disease has begun to spread beyond its primary site. Surgical removal serves both diagnostic and therapeutic purposes.
The Role of Lymph Node Removal in Cancer Staging
The primary reason for removing lymph nodes is to accurately determine the extent of the cancer’s spread, a key step in cancer staging. Staging systems, such as the TNM classification, rely on this information to define the severity of the disease and guide subsequent treatment decisions. Analyzing the removed nodes for malignant cells helps doctors establish the N-status, or “node” status, of the cancer.
The lymphatic system acts as a major pathway for cancer to travel. If cancer cells are found within the nodes, it signifies that the disease has progressed and may require more aggressive systemic therapy, such as chemotherapy, hormone therapy, or radiation. Conversely, if the lymph nodes are clear, it suggests a lower risk of systemic spread, potentially allowing for less intensive post-surgical treatments. Removal also serves a therapeutic function by physically taking cancer cells out of the body.
Different Surgical Approaches to Removal
The surgical strategy for removing lymph nodes is carefully chosen based on the type of cancer, its apparent stage, and whether the nodes are already known to contain cancer. There are two primary surgical methods that offer different levels of invasiveness and diagnostic detail.
Sentinel Lymph Node Biopsy (SLNB)
This is a targeted procedure that focuses on identifying and removing only the “sentinel” node or nodes—the very first lymph nodes that receive drainage from the primary tumor area. A surgeon identifies these specific nodes by injecting a radioactive tracer or blue dye near the tumor, which then travels to the sentinel nodes, making them visible for removal. This targeted biopsy is typically performed when there is no clinical evidence that cancer has spread to the lymph nodes. If the sentinel nodes are negative for cancer, a more extensive surgery can often be avoided.
Lymph Node Dissection
Also known as a lymphadenectomy, this procedure involves the removal of a larger cluster of lymph nodes from a specific region, such as the axilla, neck, or pelvis. Dissection is a more extensive operation necessary if the sentinel node biopsy shows cancer, or if imaging tests prior to surgery indicated significant involvement. For instance, an Axillary Lymph Node Dissection (ALND) for breast cancer involves removing 10 to 20 or more nodes from the armpit area. This comprehensive removal provides a thorough evaluation of the disease extent and physically removes all known or suspected cancerous nodes.
Life and Health After Lymph Node Removal
A significant and common consequence of lymph node removal is the risk of developing lymphedema, a condition involving swelling. Lymphedema occurs because the removal or damage to the lymph nodes and vessels impairs the lymphatic system’s ability to drain fluid from the tissues. This accumulation of protein-rich fluid most often affects the arm or leg on the side of the surgery.
The risk of developing this chronic condition is directly related to the extent of the surgery. Patients who undergo a full lymph node dissection have a significantly higher risk (estimated 20% to 25% for a procedure like ALND) compared to a much lower risk (approximately 5% to 7%) for those who only have a sentinel lymph node biopsy. The swelling may appear months or even years after the initial treatment.
While lymphedema is a long-term concern, patients may also experience immediate post-operative effects like temporary numbness, tingling, or a restricted range of motion near the surgical site. Management of lymphedema often involves specialized techniques, including manual lymphatic drainage, wearing compression garments, and engaging in specific physical therapy exercises aimed at stimulating fluid circulation and reducing swelling.