Non-sentinel lymph node analysis with one-step nucleic acid amplification in breast cancer patients

Background: One-step nucleic acid amplification (OSNA) examines lymph node metastasis in a semi-quantitative manner with molecular biology techniques. In this study, we conducted a whole-node analysis of non-sentinel lymph nodes (SLNs) using the OSNA method in SLN metastasis-positive breast cancer patients. Methods: With the OSNA method, we compared the rates of positivity of non-SLN metastasis in cases with both SLN micro-and macrometastases. Results: The rates of non-SLN metastasis positivity in those with SLN micrometastasis and macrometastasis were 44% and 48%, respectively, and this difference was not significant. When the study of non-SLN metastasis positivity was focused only on macrometastases, the rates of non-SLN metastasis positivity in patients with SLN micrometastasis and macrometastasis were 19% and 22%, respectively, and there was no significant difference. Conclusion: Regardless of the copy number of SLN metastases, non-SLN metastases were found in approximately half of the cases. (C) 2015 Elsevier Ltd. All rights reserved.