Depending on the size and other characteristics of the breast cancer, you may have one to 10 or more lymph nodes removed. Here are a few things to keep in mind:
- Your surgeon will probably remove any nodes that feel cancerous.
- During sentinel node dissection, the surgeon looks for the sentinel node or nodes, which is the first node or first few lymph nodes that filter fluid draining away from the breast. If cancer cells are traveling in the lymph system, the sentinel node is more likely than the others to contain them. So, rather than remove 10 or more nodes, the surgeon removes only the one node, or a cluster of two or three, which is most likely to have cancer. If the sentinel node is clean, chances are the other nodes are clean, too.
- During axillary lymph node dissection, the surgeon removes an irregular pad of fatty tissue in the armpit that contains the lymph nodes. The lymph nodes are embedded in this fat, and can often feel just like the fat. Often the surgeon can't count all the lymph nodes at the time of surgery. For this reason, you probably won't know how many nodes were removed and how many of those were positive (involved in the cancer) until the pathologist analyzes the tissue.
- The pathologist has to look carefully through the piece of fatty tissue taken from the axilla to find all of the lymph nodes.
- How many lymph nodes are removed depends just as much on your normal anatomy as it does on the surgeon's and pathologist's skill. Every woman has a different number of lymph nodes under her arm — some may only have five nodes and others may have more than 30.
To make sure that women have the appropriate lymph node surgery, the American Society for Clinical Oncology released guidelines on sentinel lymph node biopsy for people diagnosed with early-stage breast cancer. The guidelines say sentinel lymph node biopsy SHOULD be offered under these circumstances:
- breast cancer in which there is more than one tumor, all of which have formed separately from one another (doctors call these multicentric tumors); these types of breast cancers are rare
- DCIS treated with mastectomy
- women who have previously had breast cancer surgery or axillary lymph node surgery
- women who have been treated before with chemotherapy or another systemic treatment (treatment before surgery is called neoadjuvant treatment)
Sentinel node biopsy SHOULD NOT be offered under these circumstances:
- the cancer is 5 cm or larger or locally advanced (the cancer has spread extensively in the breast or to the nearby lymph nodes)
- the cancer is inflammatory breast cancer
- DCIS treated with lumpectomy
- the woman is pregnant
The guidelines also say:
- Women with negative sentinel node biopsies shouldn’t have axillary node surgery.
- Women with one or two positive sentinel nodes who plan to have lumpectomy plus radiation also don’t need axillary node surgery.
- Women who have one or more positive sentinel nodes and plan to have mastectomy with no radiation should be offered axillary node surgery.