One-step Nucleic Acid Amplification for Detection of Lymph Node Metastasis in Lung Cancer

Abstract

Objective: Intraoperative diagnosis of lymph node (LN) metastasis is critical in lung cancer patients. The one-step nucleic acid amplification (OSNA) assay is a novel technique using a loop-mediated isothermal amplification method of gene amplification. The objective of this study was to investigate whether the OSNA assay provides sufficient diagnosis of LN metastasis in lung cancer patients. Methods: A total of 40 LN stations were dissected from the 20 patients, who had curative lobectomy for lung cancer. The cut halves of LNs were used for pathological diagnosis, and other halves were for the OSNA assay. The OSNA assay used cytokeratin (CK) 19 mRNA as a marker. The CK19 mRNA copy number was detected using RD-100i (Sysmex Corp., Hyogo, Japan). One formalin-fixed section with the largest cutting surface of the other halves of LNs was used for pathological examination. When discordance was observed between OSNA assay and usual pathological examination, an additional examination using 1-mm interval sections was performed. Results: In the forty LN stations, three stations were diagnosed as LN metastasis positive pathologically. In these three, the OSNA assays showed extremely high numbers of CK19 mRNA copies. When the cutoff value was set to 250 copies/µl, 4 stations with relatively low copy numbers were found to be discordant. Of the 4 discordant cases, one was shown to be micro-metastasis positive in the additional pathological assessment. The sensitivity of the OSNA assay was 100.0%, and its specificity was 91.7%. Conclusions: This method could be applied to intraoperative assessment LNs metastasis.

A more sensitive detection of micrometastases of NSCLC in lymph nodes using the one‐step nucleic acid amplification (OSNA) method

“…In the case of pulmonary tumors, there are only a limited number of references related to the application of the OSNA method—just a few recent publications . Maybe one of the reasons is that lung cancer, on the contrary to breast or colorectal cancer, is a type of cancer without sentinel lymph node concept.…”

“…The detection was therefore also performed in a diluted sample allowing the inhibition of the reaction to be revealed. The result allows the detection of the presence of tumor cells (cut off = 250 copies of mRNA CK19/μL) . The results are available in approximately 30 min in case of up to four groups of pooled LNs.…”

“…In the case of pulmonary tumors, the OSNA method has not been employed on a routine basis. However, it has been the subject of several studies the goals of which were to ascertain the presence of CK19 in these tumors and to compare it with the H&E method . Recently, Oezkan et al published a study on the use of OSNA method for LN staging for pretreatment lung cancer management …”

Lymph Node Positivity in One-Step Nucleic Acid Amplification is a Prognostic Factor for Postoperative Cancer Recurrence in Patients with Stage II Colorectal Cancer: A Prospective, Multicenter Study

“…Subsequent studies have further demonstrated the high sensitivity of OSNA in detecting LN metastasis of breast, gastric, lung, and colorectal cancers. [9][10][11][12][13][14][15][16] Our own previous prospective, multicenter studies conducted in Japan demonstrated the usefulness of the OSNA assay as a complementary tool for diagnosing LN metastasis and CRC staging. 17,18 The later study revealed that 17.6% (13/74) of patients with histologically node-negative stage II CRC were nodal positive by the OSNA assay.…”

RNAi-mediated A disintegrin and metalloproteinase 9 gene silencing inhibits the tumor growth of non-small lung cancer in vitro and in vivo

“…Metastasis is a major cause of morbidity and mortality in NSCLC cancer. Surgical resection of primary lung cancer is frequently followed by tumor recurrence at distant sites, including the lymph nodes (5), bone (6) and brain (7). Therefore, in depth investigations into the mechanisms underlying NSCLC invasion and metastasis are required to gain insights into disease progression and to identify potential therapeutic targets and treatment strategies.…”