Evaluation of Exudative Pleural Effusions: A Multicenter, Prospective, Observational Study.

PURPOSE: The aim of this study is to determine the diagnostic performances of pleural procedures in undiagnosed exudative pleural effusions and to evaluate factors suggestive of benign or malignant pleural effusions in tertiary care centers. METHODS: This was a multicenter prospective observational study conducted between January 1 and December 31, 2018. A total of 777 patients with undiagnosed exudative pleural effusion after the initial work-up were evaluated. The results of diagnostic procedures and the patients' diagnoses were prospectively recorded. Sensitivity, specificity, and accuracy estimates with 95% confidence intervals were used to examine the performance of pleural procedures to detect malignancy. RESULTS: The mean age ± SD of the 777 patients was 62.0 ± 16.0 years, and 68.3% of them were male. The most common cause was malignancy (38.3%). Lung cancer was the leading cause of malignant pleural effusions (20.2%). The diagnostic sensitivity and accuracy of cytology were 59.5% and 84.3%, respectively. The diagnostic sensitivity of image-guided pleural biopsy was 86.4%. The addition of image-guided pleural biopsy to cytology increased diagnostic sensitivity to more than 90%. Thoracoscopic biopsy provided the highest diagnostic sensitivity (94.3%). The highest diagnostic sensitivity of cytology was determined in metastatic pleural effusion from breast cancer (86.7%). CONCLUSION: The diagnostic performance increases considerably when cytology is combined with image-guided pleural biopsy in malignant pleural effusions. However, to avoid unnecessary interventions and complications, the development of criteria to distinguish patients with benign pleural effusions is as important as the identification of patients with malignant pleural effusions.

IGFBP-4: A promising biomarker for lung cancer.

Background: Insulin-like growth factor binding protein-4 (IGFBP-4), a member of the insulin-like growth factor (IGF) family, transports, and regulates the activity of IGFs. The pregnancy-associated plasma protein-A (PAPP-A) has proteolytic activity towards IGFBP-4, and both proteins have been associated with a variety of cancers, including lung cancer. Thus, we aimed to evaluate the use of IGFBP-4 and PAPP-A as potential biomarkers for lung cancer. Methods: Eighty-three volunteers, including 60 patients with lung cancer and 23 healthy individuals, were included in this study. The patients with lung cancer were selected based on their treatment status, histological subgroup, and stage of the disease. Enzyme-linked immunosorbent assays were used to assess the serum levels of IGFBP-4 and PAPPA, whereas the IGF-1 levels were measured using a chemiluminescent immunometric assay. Results: The serum IGFBP-4 levels in all patient groups, regardless of the treatment status and histological differences, were significantly higher than those in the control group (p<0.005). However, the serum PAPP-A levels in the untreated patient group were found to be higher than those in the control group, but this difference was not statistically significant (p=0.086). Conclusions: The serum PAPP-A and IGFBP-4 levels are elevated in lung cancer. However, IGFBP-4 may have better potential than PAPP-A as a lung cancer biomarker.