have a mastectomy or breast-conserving surgery (lumpectomy) for
breast cancer, your doctors need to know whether the
cancer has spread to the
lymph nodes. Lymph node involvement increases the
likelihood that cancer cells have spread through the bloodstream to other parts
of the body. Women with some forms of very early breast cancer, such as
lobular carcinoma in situ, do not need lymph node
There are two ways for your doctor to check the lymph
nodes under your arm. They are:
- Axillary lymph node dissection. During this surgery, some of the lymph
nodes in the armpit are removed and checked for cancer cells.
- Sentinel lymph node biopsy. This is a procedure in which tissue is removed from
the lymph node closest to the cancer—the sentinel node (SN) or group of
nodes—to help find out whether breast cancer has spread to this area.
If the lymph node biopsy results show cancer, more lymph nodes may be removed.
Removing lymph nodes from under the arm can sometimes cause lymphedema, a swelling in the arm.
In the past, doctors believed that removing as many lymph nodes as
possible would improve chances for cure. But lymph node surgery itself
does not improve your chances for a cure. Treatment with chemotherapy, hormone therapy, or targeted therapy offers the best chance of destroying cancer cells that have spread
beyond the breast.