Lymph nodes are small groups of tissue that filter your body fluids. The lymph nodes in your underarm also known as axillary lymph nodes filter the fluid that comes from your breast. The axillary node dissection is a test to determine if your cancer has spread from the breast. It is a surgical procedure that is not curative but rather helps provide a detailed diagnosis. A specified amount of fat tissue (containing the nodes) is removed from under the arm of your affected breast.
Sentinel node biopsy is an new technique in which fewer nodes are sampled. This procedure may be on option instead of a full axillary node dissection in the future.
Axillary node dissection is not usually recommended for ductal cancer in situ. Most oncology experts agree that the risks of axillary node dissection outweigh the benefits for women with ductal cancer in situ. Less than one percent of these patients' cancer will have spread to the lymph nodes.
However, Axillary node dissection is usually recommended for invasive breast cancer.
In any case, it is a good idea for you to meet with your surgeon to carefully weigh the risks and benefits before choosing this procedure.