Utility of the one-step nucleic acid amplification assay in sentinel node mapping for early gastric cancer patients

Abstract

Background To safely perform minimized gastrectomy based on sentinel node (SN) concept for early gastric cancer patients, intraoperative diagnostic accuracy is indispensable. This study aimed to evaluate the clinical utility of the one-step nucleic acid amplification (OSNA) assay in the intraoperative diagnosis of SN metastasis in early gastric cancer patients compared with that of histopathological examination. Methods We conducted a prospective study using the OSNA assay for 43 patients with cT1N0M0 gastric cancer undergoing gastrectomy with SN mapping. All the SNs and selected non-SNs were examined by routine histopathological diagnosis, and the OSNA assay. Results We performed permanent histopathology (PH) in 1732 lymph nodes (LNs) (286 SNs and 1446 non-SNs) obtained from 43 patients. We also evaluated 439 LNs (286 SNs and 153 non-SNs) with the OSNA assay in addition to PH. Intraoperative histopathology (IH) was performed in 214 LNs (213 SNs and 1 non-SN). PH revealed LN metastasis in 6 patients (14%), all of whom showed positive SNs by PH. The diagnostic accuracy to predict the LN status based on the SN concept by histological examination was 100%. The concordance rate between the OSNA assay and the PH and IH were 0.970 and 0.981 respectively. Discordant results between PH and OSNA assay were observed in 13 LNs. The sensitivity and specificity of the OSNA assay compared with those of PH were 0.636, and 0.988, and compared with those of IH were 0.800, and 0.995. Conclusion Our results suggest that the OSNA assay is a useful and convenient tool for the intraoperative detection of SN metastasis in early gastric cancer patients.

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

“…Moreover, in the current study, SLNs had to be identified in the unfixed state. While the original protocol achieved results that were comparable with the favorable results of Japanese authors using in-vivo SLN mapping [ 23 , 25 ], this was not true in the current study. The efficacy of the protocol was too low to enable restricting the analysis to the identified SLNs.…”

“…To the best of our best knowledge, this is the first study outside Japan to apply the OSNA technique for LN analysis in gastric cancer. The high efficacy of OSNA in detecting LN metastases has been shown in former studies from Japan ( Table 3 ) [ 22 , 23 , 24 , 25 ]. Therefore, it was the aim of this study to evaluate OSNA in a European center, where it is unusual to perform post-operative LN dissection in the unfixed state.…”

“…The evaluation of its feasibility in combination with an ex vivo SLN mapping technique was the secondary study aim. It is noteworthy that the rationale behind this study’s sentinel mapping concept differs fundamentally from the other published studies combining SLN mapping with OSNA [ 23 , 25 ]. Usually, SLN mapping aims to reduce the extent of an operation.…”

“…Conducting a multicenter study, Itabashy et al could demonstrate that OSNA is not only safe but moreover prognostic in stage II colon cancer even after multivariable analysis [ 21 ]. In addition, some studies addressing OSNA have also been conducted with gastric carcinoma [ 22 ], with two of them specifically evaluating SLNs [ 23 , 24 ].…”

Rapid Detection of Free Cancer Cells in Intraoperative Peritoneal Lavage Using One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer Patients

“…Reaction mixture contained tree pairs of primers: 5′-GGAGTTCTCAATGGTGGCACCAACTACTACACGACCATCCA-3′ (CK19 forward inner primer), 5′-GTCCTGCAGATCGACAACGCCTCCGTCTCAAACTTGGTTCG-3′ (CK19 reverse inner primer), 5′-TGGTACCAGAAGCAGGGG-3′ (CK19 forward outer primer), 5′-GTTGATGTCGGCCTCCACG-3′ (CK19 reverse outer primer), 5′-AGAATCTTGTCCCGCAGG-3′ (CK19 forward loop primer), and 5′-CGTCTGGCTGCAGATGA-3′ (CK19 reverse loop primer) [ 16 ]. The RT-LAMP method measured the time taken to exceed a predetermined threshold turbidity caused by magnesium pyrophosphate, which is a by-product of the amplification reaction [ 17 ]. The change in turbidity correlates with the CK19 mRNA copy number calculated from the value of the standard curve, which was previously determined with three calibrators containing different concentration of CK19 mRNA copy number/µL [ 14 , 18 ].…”