Surgery

Surgery is used to remove the primary tumor and generally the first draining lymph nodes in order to evaluate whether the cancer has spread to them.  Almost every patient diagnosed with breast cancer will have surgery as part of their treatment.  Breast cancer surgery should be done by a surgical oncologist who specializes in breast cancer.  Surgical options vary and depend on the size and location of the tumor and on the patient's personal preference.  You should discuss these options with your surgical oncologist.

Breast Conserving Surgery/Lumpectomy/Segmental Mastectomy is the removal of the tumor and a small, clear (cancer-free) margin of normal breast tissue around the tumor.  This type of surgery is appropriate for patients with focal ductal carcinoma in situ (DCIS) or whose breast tumors are smaller in comparison to the size of their breast.  Tumors must not be multicentric – meaning that they cannot be in distant areas of the breast.  This approach leaves most of the breast intact.  Almost all patients undergoing breast conservation therapy will undergo adjuvant radiation therapy.

Mastectomy is the surgical removal of the entire breast.  For larger tumors, those that are multicentric, or for some specific types of breast cancer, mastectomy remains the only option.  After a mastectomy, you may choose to have breast reconstruction surgery.

Lymph Node Dissection and Evaluation
Regardless of whether you have a lumpectomy or mastectomy, if your breast cancer is invasive, your surgeon will usually remove the lymph nodes under your arm – the axillary nodes – to determine whether the cancer has spread to them.  It is best to think of surgical breast cancer treatment as surgery for the breast and surgery for the axilla.  If the cancer is in situ, meaning it does not have the potential to spread to the lymph nodes, normally patients do not undergo lymph node dissection.

Lymph node evaluation can be done one of two ways.  The traditional method, axillary node dissection, involves removing as many nodes as possible and analyzing them all for the presence of cancer.  The actual number of nodes removed varies, but the pathologist examines all of them and notes those that contain cancer cells and the extent of the cancer cell invasion into the nodes. 

A newer technique, the sentinel lymph node biopsy, allows for the removal of one to five lymph nodes.  These "sentinel nodes" are the first draining lymph nodes of the breast and are the most likely to be cancerous, which the pathologist analyzes for cancer cells.  If the sentinel nodes are cancer free, research has shown that the other nodes are also likely to be cancer free.  If the sentinel node shows the presence of cancer, the surgeon will remove additional nodes depending on whether the patient is undergoing a mastectomy or breast-conserving therapy.  New data has demonstrated that in patients undergoing breast-conserving therapy with post-operative radiation who only have two or fewer positive sentinel lymph nodes, removal of additional lymph nodes does not improve local recurrence or overall survival.  However this is in a select group of patients. 

All in all, the sentinel lymph node biopsy is used for patients with early breast cancer who do not have known lymph node metastasis prior to surgery.  The advantage of the sentinel node biopsy is that it greatly reduces the incidence of lymphedema (swelling in the arm) following surgery.