Peptide nucleic acid locked nucleic acid polymerase chain reaction clamp method

One hundred fifty-two lung cancers from 59 patients who were treated at the Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, between March 2003 and May 2016 were included in this translational study. The eligible patients included lung cancer patients who had multiple intrapulmonary nodules that were diagnosed as synchronous multiple primary lung cancer (MPLC), metachronous MPLC (second primary lung cancer), or pulmonary metastasis (PM). All of the lesions were resected and had to be available for an immunohistochemical analysis to detect PD-L1. Pathology staging was performed using the seventh edition of the TNM Classification of Malignant Tumors. In addition to the pathology stage, the patients' age, sex, performance status, smoking history, pathologic tumor and pathologic lymph nodal factors, pleural invasion, lymphatic invasion, vascular invasion, histologic subtype (2015 World Health Organization classification), surgical procedures, and EGFR mutation status were examined. In all specimens, the EGFR mutation status of the tumor tissue was determined using the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method (Mitsubishi Chemical Medience, Tokyo, Japan). The present study was approved by our Institutional Review Board (Kyushu University, IRB no. 29-52).