When breast cancer spreads, the first place it often travels is to nearby lymph nodes (bean-shaped organs that produce infection-fighting cells and filter lymph fluid as it circulates through the lymphatic system) in the armpits. That’s why your healthcare provider may check your lymph nodes for the presence of cancer.
The first step will likely be a sentinel node biopsy. That entails locating (using a special radioactive dye), removing and examining the sentinel node (the first node in line as lymph fluid drains from your breast).
If the biopsy reveals cancer, the healthcare provider may suggest traditional lymph node removal surgery, called axillary (underarm) dissection. Because it’s more extensive than sentinel node biopsy, it increases the risk of post-surgical arm swelling, known as lymphedema.