UNASSIGNED: 194 Background: One step nucleic acid (OSNA) is a recently developed molecular diagnostic assay to detect lymph node @entity3 . Aim of the present study was to assess OSNA for intra-operative detection of @entity1817 @entity3 with use of standard histopathology as the "gold standard." Moreover, discordant cases were further investigated to assess their impact on @entity1 ' management. METHODS: 157 @entity0 @entity1 with clinically and ultrasonographically negative axilla underwent axillary staging with @entity1817 ( @entity1817 ) biopsy. 244 SLNs were evaluated by OSNA and standard histopathology (alternate slices were submitted to OSNA and standard test). The "turn-around time" taken for an intra-operative OSNA result was recorded. RESULTS: Sensitivity and specificity of OSNA were 92.3% and 95.6% respectively with positive predictive value of 80% and negative predictive value of 98.4%. The average time taken for an intra-operative result in this group was 34 minutes. Concordance rate was 95% while 12/244 nodes showed discordant results between OSNA and Histology. The discordant cases were re-evaluated by histopathologists and characteristics of this subgroup analysed. @entity1 's management was altered by OSNA alone in 5 @entity1 as they underwent axillary lymph node dissection on the basis of a positive OSNA when histopathology did not show evidence of @entity3 . Two @entity1 with nodes negative on OSNA had histopathology results showing @entity3 requiring delayed axillary clearance. The rest of the discordant nodes belonged to @entity1 who had other nodes biopsied concurrently that were concordant in OSNA and histology. CONCLUSIONS: OSNA is a fast, valuable and highly accurate standardised method for the intra-operative evaluation of axillary lymph node @entity3 and is part of our routine intra-operative assessment tool for sentinel nodes in @entity0 .

Evaluation of one-step nucleic acid (OSNA) molecular assay for intra-operative diagnosis of sentinel lymph node XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'Patient'] @entity1817 :: ('MESH:D012804', 'Disease') :: ['SLN', 'sentinel node'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis', 'metastases']
@entity3 :: (MESH:D009362,Disease) :: ['metastasis']
