What is sentinel lymph node biopsy?
The sentinel lymph node is the first lymph node, or group of nodes, that receives drainage from a breast tumour. If cancer is going to spread through the lymphatic system, the sentinel node is where it is most likely to appear first.
A sentinel lymph node biopsy (SLNB) removes only these specific nodes for examination, rather than all the lymph nodes in the armpit. If the sentinel nodes are clear of cancer, the remaining nodes are almost certainly clear as well, and a full axillary clearance can be avoided.
Why it matters
Before SLNB became standard practice, breast cancer surgery routinely included axillary lymph node dissection (removal of many lymph nodes from the armpit). This often caused lymphoedema, a permanent swelling of the arm, as well as shoulder stiffness and numbness. SLNB has dramatically reduced these complications by making full clearance unnecessary in node-negative patients.
Knowing whether the sentinel nodes contain cancer also guides treatment decisions, including whether additional chemotherapy or radiation is needed.
The procedure
SLNB is performed under general anaesthesia at the same time as the lumpectomy or mastectomy. A small amount of radioactive tracer and/or blue dye is injected near the tumour before or during surgery. The tracer travels through the lymphatic channels to the sentinel node(s). Dr. Shruthi identifies and removes these nodes through a small incision in the armpit.
The removed nodes are sent to the histopathology laboratory. Results are usually available within a few days. If cancer cells are found in the sentinel nodes, a further discussion about axillary clearance or additional treatment follows.
Recovery
- SLNB is performed through a small (2 to 3 cm) incision in the armpit
- Recovery is usually straightforward and does not significantly add to the recovery from the main breast surgery
- Some patients notice temporary numbness or bruising in the armpit area
- The small amount of blue dye used may temporarily discolour urine
- Long-term complications such as lymphoedema are uncommon after SLNB alone
SLNB is now the standard of care for clinically node-negative breast cancer. If your surgeon has recommended full axillary clearance without first attempting SLNB, it is worth seeking a second opinion to understand whether this is truly necessary in your case.