When most people think about breast cancer, they don’t often think about the small, pea-sized structures that dot the body and help fight infections and other foreign substances. But it’s top-of- mind for many patients who undergo surgery for breast cancer.
Lymph nodes are sites for cancer spread, and certain nodes are removed during surgery depending on a number of factors. Data published originally in the Annals of Surgery in September 2010 and today in the Journal of the American Medical Association show that certain nodes in select patients may not need to be removed.
Removing lymph nodes can cause discomfort, numbness, lymphedema, and limit range of motion.
In breast conserving surgery (or lumpectomy) for early stage cancers, surgeons typically remove the sentinel lymph node, found in the armpit, and send it to pathologists for evaluation, sometimes while the patient is still in the operating room. The sentinel lymph node is the first place where breast cancer will spread. If pathologists find no evidence of breast cancer in the sentinel lymph node, no additional lymph nodes need to be removed, but if breast cancer cells were found in that node, more lymph nodes – about 10 to 12 of them in the axillary area of the armpit -- are removed.
Why remove all the axillary lymph nodes? The idea was to surgically remove as much cancer as possible, says Mehran Habibi, M.D., assistant professor of surgery at Johns Hopkins. But since the majority of lumpectomy patients receive radiation after surgery, doctors now believe the radiation may be mopping up residual cancer cells in the axillary lymph nodes.
The current study was conducted in 891 breast cancer patients whose tumors were not very large – mostly up to 2 cm (called T1) and some no larger than 5 cm (T2). These patients also had no palpable enlargement of their lymph nodes. All of the patients had lumpectomies, and their sentinel lymph nodes contained breast cancer cells. Patients were randomized to receive axillary lymph node removal of at least 10 nodes or no further lymph node removal. After about six years of follow-up, rates of recurrence and survival were almost the same for both groups. See full study results.
Habibi says another study done almost 35 years ago also may have shown that removing axillary nodes would not add to survival. In that study, patients were randomized to radical mastectomies and complete axillary node removal, another group to total mastectomy plus nodal radiation, while another group had mastectomies only without nodal dissection or radiation to the axillary area. There was no difference in survival between these groups, however significantly higher rates of local recurrence were observed. This can be due to the larger size of tumors in the previous studies, and significant differences in the radiation and chemotherapy methods and agents used three decades ago.
“Now, we have evidence on the utility of axillary node removal from a randomized, prospective study utilizing current treatments including lumpectomy, better radiation, chemotherapy and imaging techniques, which are more applicable to today’s clinical practice,” said Habibi.
At Johns Hopkins, surgeons including Habibi will discuss the current study results with patients. Habibi says that patients who may opt to forego axillary lymph node removal are those whose tumors are classified as T1 and early T2 (about to 2-3 cm in size) and scored by pathologists as Grade 1 or 2, and are candidates for radiation and possibly chemotherapy.
“This can significantly improve the clinical outcome of patients by reducing the complications associated with complete nodal dissection without a negative effect on survival or local recurrence,” says Habibi. He cautions that this is not for patients receiving mastectomies, patients undergoing lumpectomies without radiation, patients receiving neoadjuvant chemotherapy, and those being treated with partial breast irradiation.
More information on axillary node dissection.