Prediction of Pleural Invasion in Challenging Non-Small-Cell Lung Cancer Patients Using Serum and Imaging Markers

Introduction. Preoperative detection of pleural invasion in lung cancer patients is key to curative surgical treatment. We tried to predict pleural invasion in non-small-cell lung cancer patients with <100？ml pleural fluid. Methods. Patients admitted from August 1, 2011, to December 31, 2018, were retrospectively retrieved. Records of serum and imaging markers were analyzed. Results. Among 7004 patients who received surgery, 43 cases with <100？ml pleural fluid who had pleural invasion were included, and another 108 cases without pleural invasion were enrolled as controls. There were no differences in squamous cell carcinoma antigen (SCC) or neuron-specific enolase (NSE) values between the pleural invasion and noninvasion groups ( and 0.14, respectively), but there were significant differences in carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA21-1) values ( and 0.01, respectively). There were significant differences in the location of original lung cancer (right mid lobe, ), maximum lung lesion diameter ( ), volume of pleural fluid (nondetectable vs. detectable fluid, ), pleural sign ( ), and positron emission tomography/computed tomography- (PET/CT-) predicted pleural invasion ( ) between the pleural invasion and noninvasion groups. The maximum Area-Under-the-Curve in the Receiver Operating Characteristic curve analysis was achieved with the combination of CEA, CYFRA21-1, detectable pleural fluid, PET/CT prediction, pleural sign, and location of the lung lesion. Conclusions. Serum CEA and CYFRA21-1, location of original lung cancer (right mid lobe), maximum diameter, CT-detectable pleural fluid, pleural sign by CT, and PET/CT-predicted pleural invasion were good markers for the prediction of pleural invasion in non-small-cell lung cancer patients