Intraoperatively-palpable "non-sentinel" nodes: should they be removed?

Background: Sentinel lymphadenectomy is the standard of care for evaluation of the axilla in breast cancer. Not infrequently, despite a clinically negative axilla, axillary nodes are found and removed that are only palpable intraoperatively at the time of sentinel lymph node biopsy. There is limited data suggesting that their resection is beneficial, and there is some controversy over whether these non-hot, non-blue nodes should also be called "sentinel nodes" (SNs). Methods: A retrospective chart review was conducted of breast cancer patients who underwent sentinel lymph node biopsy from 2007 to 2011 at a single institution. Patients were only included if they had SNs removed (defined as blue and/or radioactive nodes), as well as additional non-sentinel nodes that were only palpable intraoperatively (pNSNs) and not part of an axillary dissection (ALND). Pathology of both SNs and pNSNs were reviewed. Histologic nodal evaluation was performed by H&E alone. Results: From 2007 to 2011, a total of 59 patients had both SNs and pNSNs removed. Fifty-five patients (93.2%) were female and the average age was 55 years old. Fifty-two patients (88.1 %) had invasive ductal carcinoma while 7 had lobular carcinoma (11.9%). Average tumor size was 2.0 cm. Among the 59 patients, a total of 109 SNs (mean 1.8, median 1, range 1-6) and 202 pNSNs (mean 3.4, median 2, range 1-30) were removed at the same surgery. Twenty patients (33.9%) had metastases in either the SNs and/or pNSNs with 16 (80.0%) of these having metastases in the SNs alone. Sixteen patients proceeded to an ALND. There were 4 patients (6.8%, 95% CI 1.9-16.5%) who had SNs negative for tumor but pNSNs positive for tumor, and 4 (6.8%, 95% CI 1.9-16.5%) separate patients who had extracapsular extension (ECE) in their pNSNs but no ECE in the SNs. The pNSNs thus provided information altering operative treatment by American College of Surgeons Oncology Group (ACOSOG) Z0011 trial criteria in 8 patients (13.6%). Two patients (3.4%, 95% CI 0.4-11.7%) had ECE present in ALND nodes, but not present in either their SNs or pNSNs. Conclusion: pNSNs provide information that changes the surgical plan by ACOSOG Z0011 criteria in 14% of cases. Whether their removal changes patient outcomes remains unclear, especially as SNs and pNSNs may, together, be falsely-negative for ECE present within the axilla. While we recommend their removal at this time based upon the added information they provide, further study is required to determine whether the changes resulting from pNSN dissection (i.e. need for ALND) provide any outcome benefit in this era of effective systemic therapy. [ABSTRACT FROM AUTHOR]