Benefits of sentinel node dissection
With sentinel node dissection, a surgeon may only have to remove one lymph node, or a small cluster of two or three nodes, to know whether or not breast cancer has spread to the axilla (underarm) lymph nodes. This procedure leaves the other non-involved, functional lymph nodes intact. The procedure allows critical treatment insights with the least possible surgery and trauma.
There are many good reasons why women want to minimize the number of underarm lymph nodes that are removed. Lymph node surgery can lead to uncomfortable temporary side effects, such as lymph backup in the armpit, called seroma. Other side effects can linger, including mild armpit discomfort and numbness in the armpit and the upper arm. Also, women who have only sentinel lymph node biopsy and not axillary node surgery have a much lower risk of lymphedema. Lymphedema is the build-up of lymph fluid in the soft tissues of the body, most often the arm and hand in people who’ve had breast cancer surgery, but also the breast, underarm, chest, trunk, and back. Besides swelling, lymphedema also can cause arm weakness and numbness, as well as shoulder pain. Finally, the more surgery a woman has in the breast/armpit area, the more potential there is for numbness, heightened sensitivity, and discomfort.
Drawbacks of sentinel node dissection
In some cases, it may turn out that more than one or two sentinel nodes have cancer in them. When that happens, it’s likely that more surgery — in the form of an axillary node biopsy — will be done to figure out how many lymph nodes are involved.
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.