Purpose: Detection of sentinel lymph node (SLN) metastasis in breast cancer patients has conventionally been determined by intraoperative histopathologic examination of frozen sections followed by definitive postoperative examination of permanent sections. The purpose of this study is to develop a more efficient method for intraoperative detection of lymph node metastasis. Experimental Design: Cutoff values to distinguish macrometastasis, micrometastasis, and nonmetastasis were determined by measuring cytokeratin 19 (CK19) mRNA in histopathologically positive and negative lymph nodes using one-step nucleic acid amplification (OSNA). In an intraoperative clinical study involving six facilities, 325 lymph nodes (101 patients), including 81 SLNs, were divided into four blocks. Alternate blocks were used for the OSNA assay with CK19 mRNA, and the remaining blocks were used for H&E and CK19 immunohistochemistryb ased three-level histopathologic examination. The results from the two methods were then compared. Results: We established CK19 mRNA cutoff values of 2.5 Â 10 2 and 5 Â 10 3 copies/AL. In the clinical study, an overall concordance rate between the OSNA assay and the three-level histopathology was 98.2 %. Similar results were obtained with 81 SLNs. The OSNA assay discriminated macrometastasis from micrometastasis. No false positive was observed in the OSNA assay of 144 histopathologically negative lymph nodes from pN0 patients, indicating an extremely low false positive for the OSNA assay. Conclusion: The OSNA assay of half of a lymph node provided results similar to those of three-level histopathology. Clinical results indicate that the OSNA assay provides a useful intraoperative detection method of lymph node metastasis in breast cancer patients.Sentinel lymph node (SLN) biopsy has recently become a standard surgical procedure in the treatment of breast cancer patients (1 -10). This procedure can predict metastasis to the regional lymph nodes with high accuracy and avoids unnecessary removal of axillary lymph nodes and subsequent morbidity associated with axially clearance in node negative breast cancer patients.SLN metastasis is generally detected by conventional means including the intraoperative H&E-based histopathologic examination of frozen section(s) or cytologic observation of touchimprints, followed by definitive postoperative histopathologic examination of permanent sections (2, 7 -9). However, the sensitivity of these intraoperative methods is not high. Many investigators have reported that the intraoperative H&E-based histopathologic examination has a false-negative rate of 5% to 52% (reviewed in ref. 11). Furthermore, these methods provide subjective rather than objective results, which may differ from one pathologist to another (12). On the other hand, the definitive postoperative histopathologic examination generally requires 5 to 10 days for assessment. If an accurate Imaging, Diagnosis, Prognosis

The OSNA method is feasible and acceptable for detecting LN metastases in patients with gastric cancer. This should be applied for the intraoperative diagnosis in the SN-navigation surgery in gastric cancer.

No abstract

The study data demonstrated that an OSNA assay using CK19 mRNA was applicable for detecting LN metastases in EC. Combined analysis using an OSNA assay and SLNs may improve individualized treatments according to LN metastatic status.

Our 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.