Comprehensive Guide to Lymph Node Removal for Breast Cancer

As a breast surgeon and the Chief of Breast Surgery, Dr. Holly Mason recognizes that the advancements in treatment options for patients with breast cancer are as encouraging as they are confusing. This is especially true in the case of lymph node surgery related to breast cancer.

Dr. Mason notes that for 70 years the standard treatment for breast cancer focused solely on removing the cancer via a radical mastectomy which included the removal of the entire breast, major muscle near the breast, and the adjacent lymph nodes. “While it was considered cutting edge at the time of its development, the procedure is highly invasive, disfiguring, and can leave patients with limited mobility. Fortunately, extensive research and trials have given us a better understanding of breast cancer as a disease and the value of preserving breast tissue and lymph nodes, and led to other treatment options including medication, radiation, chemotherapy, and hormonal therapy.

“The focus of treatment today,” says Dr. Mason, “is about much more than a one-size-fits-all removal of the cancer and any tissue or muscle that might have cancer. Treatment plans are now developed for each patient based on their specific cancer and other factors. Imaging, genetics, and pathology are used to inform what a treatment plan may or may not include, and, increasingly, removal of lymph nodes is not a part of most plans.”

Understanding the Role of Lymph Nodes in Breast Health

Lymph nodes are just one component of the lymphatic (lymph) system, a part of the immune system. The lymph system includes an infection-fighting fluid known as lymph, lymphatic vessels and lymph nodes. While lymph fluid circulates through the body, via lymphatic vessels, flushing out toxins and waste, lymph nodes are found in clusters throughout the body, usually where major blood vessels meet. The average adult has more than 800 lymph nodes that filter lymph and contain immune cells that fight infection. The largest clusters of lymph nodes are found in the neck, armpit, chest, upper abdomen, and groin. Most often lymph nodes are unnoticeable, but they may enlarge or swell when filtering out infection or harmful cells.

In a healthy breast, lymph nodes help regulate the fluid balance in breast tissue by draining fluid from the breast and arm. However, if there’s an invasive cancer in the breast, it often goes first to the lymph nodes in the armpit, or those found in the chest or neck. Unchecked, the cancer can be carried to other parts of the body via the lymph system, which, says Dr. Mason, is why removal of the lymph nodes was considered essential in the earliest breast cancer treatments.

“The issue,” she adds, “is that lymph node removal can lead to lymphedema, a chronic condition that causes swelling of the arm on the affected side and, sometimes, even the leg. Patients often experience a feeling of tingling or heaviness in the arm and may have pain and difficulty moving their shoulder, elbow, wrist and fingers. Lymphedema can be quite debilitating and disfiguring.”

Dr. Mason adds, “The risk of lymphedema after a radical mastectomy was greater than 50%. Even just removing the first set of lymph nodes closest to the breast, referred to as an axillary node dissection, increases an individual’s risk of lymphedema by 15-20%, which,” she says, “makes it all the more important to avoid unnecessarily removing any lymph nodes if possible. So, the challenge for physicians who were performing surgery for breast cancer became how do you assess the lymph nodes for the spread of cancer while at the same time minimizing the risk of lymphedema. Fortunately, the answer began to emerge in the late 1990s.”

Sentinel Node Identification and Removal: A Revolution in Breast Cancer Care

One of the biggest changes to breast cancer treatment options came in the form of a small amount of radioactive dye. Developed just before the turn of this century, the procedure involved injecting a radioactive dye, a blue dye, or both near the site of the cancer. The dye then drained into the node closest to the cancer, referred to as the sentinel node. Dr. Mason says, “The dye lasts for about 6-12 hours and in that time, doctors used imaging to identify the sentinel node, or nodes, removed them, and then examined, or biopsied, them for cancer. If a node was negative, it confirmed the cancer had not spread to the lymph nodes. If it was positive, the next course of action was to remove all the nodes.”

She adds, “At the time, this was great news for patients with a localized cancer. However, for those with an invasive cancer which had spread to the axillary nodes, the likelihood of developing lymphedema due to node removal remained high. And so it was for the next 10 to 15 years until a landmark study in breast cancer treatment, called the Z-11 Trial, completely changed the thinking on complete node removal.”

The key finding of the Z-11 trial was that for patients with early-stage breast cancer and a positive sentinel lymph node, removal of all lymph nodes in the armpit was not necessary and could be safely omitted if only one or two sentinel lymph nodes were positive, and provided the patient received some form of systemic therapy, such as chemotherapy, hormone therapy, or immunotherapy as well as radiation.

“The trial essentially found that the survival and recurrence rates were the same for patients who had node-removal surgery and those who didn’t,” explains Dr. Mason. “In fact, the risk of complications—largely lymphedema—was greater for patients who had surgery to remove nodes. This was revolutionary information and continues to be of tremendous benefit to so many patients.”

Fast forward to 2016, and the publication of the Choose Wisely Guidelines from the Society of Surgical Oncology further discouraged unnecessary medical intervention. Specifically, the guidelines advised doctors to not routinely use sentinel node biopsy for women 70 years or older with small, hormone receptor–positive cancers, which is determined by a biopsy of the cancer itself.

Advances for Patients with In Situ Cancer

While radioactive dye is effective for identifying affected nodes for invasive cancers, it’s not as helpful for patients with a cancer that’s believed to be contained.

As Dr. Mason explains, “The challenge with this type of cancer, referred to as ductal carcinoma in situ (DCIS), is that 10-15% of patients who undergo a mastectomy are ‘upstaged’ to invasive cancer post-surgery. So, the practice became to remove a sentinel node for all patients undergoing the surgery because once the mastectomy was performed, we can no longer use a dye to trace back to the sentinel node. But what that meant is that for every 10 patients, 8-9 would unnecessarily get a node removed.”

Thankfully, in 2023 a new injectable, called MagTrace, was developed that’s helping to preserve lymph nodes for many patients.

Offered at Baystate Health, MagTrace is a non-radioactive, magnetic tracer that can be injected at the time of a mastectomy and remains in the lymph nodes for 30 days after injection. “This,” explains Dr. Mason, “means we can perform the mastectomy and leave the lymph nodes alone. The removed tissue is examined and if we find the cancer was contained, then we’re done. If we find the cancer has upstaged, we can go back and identify the sentinel node and remove it. The result is a whole host of patients keeping their lymph nodes and having zero risk of developing lymphedema because of node removal.”

Addressing Lymphedema Risks Before and During Surgery

For patients where node removal is deemed essential, Baystate’s breast care team offers options for addressing lymphedema risks both before and during surgery.

The first option, referred to as pre-habilitation involves identifying patients at high risk for lymphedema. Patients are connected with Baystate’s Lymphedema Management team who will teach them exercises and massage techniques to manage and minimize lymphedema. Then, during the surgery, as Dr. Mason explains, “We do reverse lymphatic mapping, which involves injecting dye into the skin of the arm to identify the lymphatics so we can avoid those areas during surgery, further minimizing lymphedema risk.”

In addition, Baystate also offers a new procedure called a lymphatic bypass. Performed during the node removal surgery, this procedure is done by a micro-surgeon who reconnects the lymphatic channels that drain the arm into a vein, so fluid doesn’t accumulate. While the procedure is relatively new, research is showing it to be vastly helpful in reducing the risk of lymphedema.