Cancer spread usually progresses in a certain order. The guard lymph node (node) is the first one or several lymph nodes where the cancer is expected to spread.
Approximately 60% of breast cancers do not spread to the armpit at the time of diagnosis. If it can be shown that there is no lymph node invasion in these patients, there is no need for axillary surgery. Possible postoperative complications are avoided. For this reason, sentinel lymph node sampling technique has been developed.
During breast surgery, a guard lymph node is found with a special blue dye or radioactive marker. Cancer cell is searched by rapid pathology evaluation (frozen section). If cancer cells are not detected, armpit surgery is not performed, but if cancer cells are detected, the remaining armpit lymph nodes are cleaned.
Pain, bruising, or, rarely, an allergy to the blue dye (methylene blue) or marker may occur in the area of the removed guard lymph node. There may also be a blue staining of the patient’s skin or urine.
The reliability of guard lymph node sampling in detecting axillary involvement has been proven in many studies. It requires a certain learning process, but it is a safe method when done correctly.