Intra-operative molecular diagnosis of sentinel lymph node and prediction of non-sentinel lymph node metastasis in breast cancer patients

To the Editor:Sentinel lymph node biopsy has become a universal procedure performed in node-negative breast cancer patients.The accurate intra-operative assessment of the sentinel lymph node(SLN)is prominent in enabling axillary lymph node dissection(ALND)synchronously performed during the breast surgery,in case of the morbidity,inconvenience,and extra cost resulting from a second operation.One-step nucleic acid amplification(OSNA)assay(Sysmex,Kobe,Japan)is a moderately sensitive molecular technique combining node tissue homogenization and subsequent reverse-transcription loop-mediated isothermal amplification of cytokeratin-19(CK-19)mRNA in a single reaction.The assay could accurately discern nodal metastases of over 0.2 mm intraoperatively.