The core sample is then evaluated to see if cancer is present. The same needle or probe can also be used with ultrasound guidance. Patients' doctors can advise them whether they are a candidate for a minimally invasive biopsy, and what type would be appropriate for them. Another advance in diagnosing breast cancer with a minimum of trauma to the patient is the sentinel lymph node biopsy, which is done once breast cancer has already been found. Standard treatment for breast cancer includes axillary node dissection, removing a cluster of lymph nodes under the arm to test them for cancer.
Lymph nodes help remove fluid that is outside blood vessels.
When axillary lymph nodes are removed, swelling of the arm and nerve irritation that causes numbness of the upper arm are possible side effects. Sentinel node biopsy involves locating the sentinel, or gatekeeper, node where cancer would spread first. This is located by injecting a safe amount of radioactive material and blue dye into the area around the cancer, and tracking the node or nodes where it spreads. The sentinel node is removed and carefully examined. If cancer is found, the remaining nodes are removed as well.