Ultrastaging Using Ex Vivo Sentinel Lymph Node Mapping and One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer: Experiences of a European Center

Abstract

Background: In this study, the effectiveness of One-step nucleic acid amplification (OSNA) in combination with ex vivo SLN mapping is compared with conventional histology including immunohistochemistry. Methods: LNs were retrieved from gastrectomy specimens in an unfixed state. After ex vivo SLN mapping using methylene-blue, LNs were sliced to provide samples for histology and OSNA. Results: In total, 334 LNs were retrieved in the fresh state from 41 patients. SLN detection was intended in 40 cases but was successful in only 29, with a correct LN status prediction in 23 cases (79%). Excluding one case out of 41 with a failure likely caused by a processing error, OSNA showed a high effectiveness with sensitivity, specificity, and accuracy rates of 85.4%, 93.5%, and 92.4%, respectively. The LN status could be predicted in all but one case, in which the single positive LN was not eligible for OSNA testing. Moreover, OSNA evaluation led to upstaging from N0 to N+ in three cases (14%). Conclusion: The ex vivo SLN protocol used resulted in a relatively poor detection rate. However, the OSNA method was not hampered by this detection rate and proved its potential to increase the sensitivity of metastases detection.

Zinc Finger Proteins in the War on Gastric Cancer: Molecular Mechanism and Clinical Potential

“…Several monogenic markers have been utilized to construct prognostic models in GC such as PPARγ [179], HDAC6 [180] and CD44 [181]. Nevertheless, no consensus has been achieved about the optimal biomarkers and methods, despite much work being put into establishing the best tools for prognosis prediction in GC [182,183]. The aforementioned discoveries have summarized numerous ZFPs regulating proliferation, metastasis, drug resistance, DNA methylation and apoptosis in GC cells.…”

Staging LaParoscopy to Assess Lymph NOde InvoLvement in Advanced GAstric Cancer (POLA)—Study protocol for a single-arm prospective observational multicenter study

“…Preparation will be done according to the manufacturer's instructions. A cutoff of 250 CK19 copies/μL will be used for differentiating between negative and metastatic LNs (14). Samples in which no LN structure could be confirmed histologically will be excluded from the data analyses.…”

“…Pooled data suggest that the OSNA assay has a high diagnostic accuracy for detecting LN metastases [12]. Recently, the effectiveness of ex vivo SN mapping with OSNA was compared with conventional histology, including immunohistochemistry in European GC patients [14]. Despite a relatively low detection rate (79%), OSNA SN evaluation showed high sensitivity, specificity, and accuracy rates of 85.4%, 93.5%, and 92.4%, respectively.…”

Molecular Cytology by One-Step Nucleic Acid Amplification (OSNA) Assay of Peritoneal Washings during D2 Gastrectomy in Advanced Gastric Cancer Patients: Preliminary Results

“…Moreover, OSNA may lead to upstaging of GC patients due to increased sensitivity of LN metastases detection [25]. As we previously described, OSNA can be applied with high diagnostic accuracy to detect FCC in intraoperative peritoneal washings of GC patients [26].…”