Until recently, guidelines recommended complete axillary node dissection in women with breast cancer for whom their sentinel node biopsy was positive. However, patients who undergo this procedure routinely experience complications. The introduction of sentinel lymph node biopsy in the 1990s included the benefit of avoiding complete axillary node dissection if two or three sentinel nodes tested negative for cancer, thus reducing morbidity. However, complete axillary node dissection was still used in patients with positive sentinel nodes. The recently completed American College of Surgeons Oncology Group Z0011 (Z-11) trial indicated that women with positive sentinel nodes scheduled for lumpectomy and whole-breast radiation could safely avoid complete axillary lymph node dissection.

A Need for Clarity

Few studies have compared the risks and benefits of the various axillary interventions for patients with breast cancer. To address this research gap, Roshni Rao, MD, and colleagues performed a systematic review of 17 studies. The analysis, published in JAMA, reviewed studies of women with breast cancer who mostly had benign axilla and received surgical treatment that ranged from removal of one lymph node to removal of all axillary lymph nodes. Outcomes of these procedures were compared with each other as well as with nonsurgical interventions, such as radiation.

Women with no suspicious, palpable axillary nodes who underwent breast-conserving therapy did not experience a benefit with complete axillary node dissection when compared with sentinel node biopsy alone. Complete axillary node dissection was associated with a 1% to 3% reduction in axillary lymph node metastases recurrence but was also associated with a 14% risk of lymphedema.

Complete axillary lymph node dissection was well suited for patients with the following:

♦ Palpable or needle biopsy-proven axillary metastases.

♦ Positive sentinel nodes among those undergoing mastectomy.

♦ More than three positive sentinel nodes when undergoing breast-conserving therapy.

♦ Did not meet eligibility criteria for recent trials that sought to establish the safety of sentinel node biopsy alone.

In patients who had benign axillary nodes on radiologic and clinical examination, sentinel node biopsy helped inform decisions about adjuvant systemic and radiation therapy.

Future Needs

“We excluded patients who underwent chemotherapy prior to breast-conserving therapy,” explains Dr. Rao. “Often, chemotherapy effectively treats cancerous lymph nodes, but these patients currently undergo complete axillary lymph node dissection. The next step in research will likely be to determine if these patients require complete axillary or only sentinel node dissection.” With or without such research, Dr. Rao says the future of breast cancer care will likely be based more on molecular profiling of the actual cancer and less on the surgical staging of the axilla.