SENTINEL LN BIOPSY
What is a sentinel node biopsy?
The word “sentinel” means a guard or someone keeping watch.
Sentinel nodes are the first lymph nodes to which cancer cells might spread from a tumour. Lymph nodes are small organs that “filter” fluid in the body and help protect from illness.
A sentinel lymph node biopsy (also called a sentinel node biopsy or SLNB) is a surgical procedure in which the surgeon removes the sentinel nodes and sends them to a lab to test for cancer cells.
Why perform a sentinel node biopsy?
Sentinel node biopsy report helps your treating doctor to know if the cancer has spread beyond the original (primary) tumour. When breast cancer spreads, it usually spreads to the sentinel nodes in the axilla (armpit) first. Spread to regional lymph nodes is not the same as metastatic or stage 4 disease and the cancer is very treatable at this stage.
When is a sentinel node biopsy performed?
A sentinel node biopsy is part of a process called staging i.e., how advanced the cancer is. Different cancer stages require different treatments. Surgeons generally (but not always) perform this test during the surgery for the primary tumour.
What are sentinel nodes?
Sentinel nodes are simply the first nodes draining a cancerous region. For breast cancer, they are usually located in the armpit. That’s why healthcare providers test the sentinel nodes to see if cancer has spread beyond the original tumor.
If there’s no sign of cancer in the sentinel nodes, it’s unlikely that cancer has spread to other lymph nodes. If the test detects cancer cells in the sentinel nodes, your provider may recommend removing other lymph nodes to check for cancer.
What should I expect during the test?
VIn some cases, few hours before the procedure, you will receive a safe radioactive substance (tracer) in your vein which will lead the surgeon to the sentinel lymph nodes.
The actual procedure is done under general anaesthesia and you will be asleep during the procedure.
Once you are asleep, your surgeon:
- Injects a blue and/or green dye around the tumor or under the nipple. Often, providers use both the dye and the radioactive tracer.
- Makes a small cut in the armpit and removes the sentinel node or nodes. Most of the time, providers remove between one and six sentinel nodes. If you are undergoing complete removal of the breast or mastectomy, then the sentinel nodes are accessed through the same mastectomy incision.
- Sends the sentinel nodes to a lab for frozen section pathology to check for cancer cells. Frozen section is quick freezing method used to make slices of the tissue for examination. Its accuracy is more than 90%. The report takes approximately 20-30 minutes and it informs your surgeon if cancer from the breast has spread to the lymph glands in the armpit. If the examined lymph nodes are clear, then no further surgery is required.
- Closes the incision and secures it with stitches or staplers. A draining tube and container may be kept in the axilla for a few days after surgery.
What should I expect after the test?
After the procedure, you can expect some soreness and discomfort near your incision and drain site. Painkillers are prescribed after the surgery to reduce the pain. You will also be advised to do physiotherapy everyday.
You can return to your day-to-day activity from the very next day but it is recommended that you wait a few weeks before starting more rigorous activities like running, exercising or lifting. You should ask your surgeon what is the best timeframe for you. You will need to keep your incision clean and give it time to heal.
What are the benefits of this test?
A sentinel node biopsy allows your provider to stage cancer accurately. It may also help you avoid unnecessary surgery.
If cancer cells are not in the sentinel nodes, it is highly unlikely that cancer has spread to other lymph nodes or other parts of the body. Your surgeon will not need to remove other lymph nodes. If the node comes positive for cancer, then the surgeon will remove all the lymph nodes in the area to remove all other positive nodes that may be present. The main job of SLNB is to provide more information about the stage at which your cancer is diagnosed and it also guides treatment after the surgery.
What are the risks of this test?
Generally, a sentinel node biopsy is a safe procedure. But every surgery has some risks. Sentinel node biopsy risks include:
- Problems at the incision site: Bleeding, bruising, swelling and pain can occur at the incision site. The incision can also become infected. Signs of infection include redness, swelling and fever.
- Allergic reaction: Rarely, some people are allergic to the contrast dye providers use to locate the sentinel node.
- Lymphoedema: This condition can happen when the lymph nodes are removed. If lymphatic fluid (lymph) cannot flow through the lymph nodes, excess fluid builds up in the body’s soft tissues. The fluid build-up causes swelling and pain. Lymphedema occurs more often when providers remove several lymph nodes.
When should I know the biopsy results?
The frozen section report is available at the time of surgery and the final pathology report (paraffin section) takes 1-2 weeks. Depending on the results, your cancer care team will recommend additional treatments.
In the rare case that your frozen section was negative and the final report is positive, you may need additional surgery to remove the remaining nodes in the area by a procedure called axillary dissection.
When should I call my healthcare provider?
Following a sentinel node biopsy, call your healthcare provider if you have:
- Bleeding from the incision or in the drain
- Fever
- Pain that does not get better with pain medication
- Swelling, warmth or redness near the incision site