The American Society of Clinical Oncology published updates to their 2005 guidelines for use of sentinel lymph node biopsy in early-stage breast cancer. The guidelines, based on the review of 9 randomized clinical trials and 13 cohort studies, reflect what ASCO believes are best practices in using the biopsy.
About Sentinel Lymph Node Biopsy
Lymph nodes are organs that help the body filter out waste, bacteria or damaged cells such as cancer cells. During a sentinel lymph node biopsy performed to guide breast cancer treatment, a surgeon removes only the lymph node or nodes in the armpit that the cancer is most likely to travel to first. This helps doctors stage the breast cancer, or find out how widespread it is, at diagnosis.
In 2005, there was a growing interest in using SLNB as an alternative to axillary lymph node dissection, ALND—surgery that removes most or all lymph nodes in the armpit near the affected breast. Like SLNB, this procedure helps determine the cancer’s stage. It also is done to remove cancer that may have spread to the lymph nodes and to prevent a regional recurrence, or a new tumor from arising in the area.
While both procedures help guide treatment, ALND is associated with more side effects. These include an increased risk of lymphedema, or swelling from the build-up of lymph fluid in the arm, chest or breast near the area of node removal. For this reason, researchers wondered if removing only the sentinel node or nodes was effective in people showing no signs that the breast cancer traveled to the lymph nodes on SNLB. If so, it would offer the benefit of staging the disease with less risk of negative side effects compared with ALND.
When ASCO published their first guidelines, few studies of SLNB were available. Now that more studies are complete, the society called together an Update Committee to reassess the guidelines.
About the Studies Used
All studies assessed were completed between 2004 and January 2013. They involved participants diagnosed with early-stage breast cancer, were phase III clinical trials or meta-analyses and compared SLNB with ALND.
What the ASCO Update Committee Recommends
- SLNB may be offered if you have cancer that can be removed with surgery and
- is multicentric, which means there are several tumors and they appear in different sections of the breast, separate from each other
- is ductal carcinoma in situ, DCIS, stage 0 breast cancer that is only in the ducts of the breast, and you plan to have mastectomy
- you had surgery to remove the breast or the lymph nodes in your armpit in the past
- you were treated with neoadjuvant, or pre-surgery, chemotherapy or hormonal therapy
- ALND may be recommended if results from SLNB show you have some positive nodes and if you plan to have mastectomy
- ALND should not be recommended if you have
- no positive lymph nodes
- 1 – 2 positive lymph nodes, and you plan on having lumpectomy followed by radiation therapy
Recommendations That Remain the Same
- SLNB should not be offered if you have
- large breast tumors or cancer that spread to nearby tissue or lymph nodes
- inflammatory breast cancer
- DCIS, and you plan to have lumpectomy
- you are pregnant
These recommendations were not changed because there was not enough data to reach new conclusions.
What This Means for You
These guidelines are what ASCO believes are best practices in using SLNB or ALND for specific situations. However, they are only suggestions. Your surgeon will recommend one to you based on your individual situation, and it’s OK to ask why either was chosen.
In general, studies suggest that fewer lymph nodes removed through SLNB lowers the risk of side effects, such as lymphedema, compared with more extensive node removal through ALND. However, studies of side effects are still ongoing, and there is no guarantee SLNB will protect against the development of lymphedema.
If you are concerned about the risk of side effects from either lymph node surgery, talk with your doctor. The benefits of SLNB and ALND often outweigh the risk of side effects.
Lyman, G, Temin, S, Edge, S, Newman, L, Turner, R, et al. Sentinel lymph node biopsy for patients with early-stage breast cancer: American Society of Clinical Oncology Clinical Practice Guideline Update. 2014; (published online March 24) doi: 10.1200/JCO.2013.54.1177