Detection of sentinel lymph node metastases in cervical cancer: Assessment of KRT19 mRNA in the one-step nucleic acid amplification (OSNA) method

Abstract

ObjectiveThe purpose of this study was to examine the utility of the one-step nucleic acid amplification (OSNA) assay using cytokeratin (CK) 19 (KRT19) messenger RNA (mRNA) for the detection of sentinel lymph node (SLN) metastases in cervical cancer patients. MethodsTo determine a cutoff value, KRT19 mRNA was assessed by OSNA assay using 239 lymph nodes (LNs) (217 histopathologically negative LNs and 22 positive LNs). A cutoff value was determined by statistical analysis of the copy numbers obtained by OSNA assay. Subsequently, performance evaluation of the OSNA assay (applying the cutoff value above) on 130 SLNs (32 patients) was used to investigate (through concordance) whether the OSNA assay exhibited diagnostic performance equivalent to the two-mm interval histopathological examination. ResultsTwo hundred fifty copies/μL of KRT19 mRNA in the OSNA assay appeared to be an optimal cutoff value. In performance evaluation of the OSNA assay, we identified five positive SLNs and 125 negative SLNs by OSNA assay using KRT19 mRNA, exhibiting 96.2% agreement with two-mm interval histopathological examination. ConclusionsOur results indicated that the KRT19 mRNA OSNA assay can detect LN metastases as accurately as two-mm interval histopathological examination and thus may be an effective additional or alternative method for a rapid intra-operative examination of SLNs in cervical cancer.