Diagnostic accuracy of tumor markers for malignant pleural effusion: a derivation and validation study

Tumor markers determination in malignant pleural effusion: pearls and pitfalls

Serum and pleural fluid tumor markers are well-recognized auxiliary diagnostic tools for malignant pleural effusion (MPE). Here, we discuss some pearls and pitfalls regarding the role of tumor markers in MPE management. The following issues are discussed in this article: What is the appropriate clinical scenario for evaluating pleural tumor markers? Which tumor markers should be advocated for diagnosing MPE? Can extremely high levels of tumor markers be employed to establish a diagnosis of MPE? Does the serum-to-pleural fluid ratio of a tumor marker have the same diagnostic efficacy as the measurement of that marker alone in the pleural fluid? Can tumor markers be used to estimate the risk of specific cancers? What should be considered when interpreting the diagnostic accuracy of tumor markers? How should tumor marker studies be performed? We addressed these issues with published works, particularly systematic reviews and meta-analyses.

Tumor Markers in Pleural Fluid: A Comprehensive Study on Diagnostic Accuracy

Background/Objectives: Malignant pleural effusions (MPEs) pose a significant challenge in clinical practice and exert a considerable socio-economic burden on the healthcare system, affecting approximately 1 million individuals annually. These effusions are a leading cause of debilitating dyspnea and a diminished quality of life among cancer patients, with distant metastasis to the pleural layers occurring in about 20% of cases during treatment. Methods: A cross-sectional, observational case-control study was conducted on 151 Bulgarian patients with a hydrothorax. The control group included 72 patients with benign diseases, confirmed via biopsy, with 38 having inflammatory and 34 non-inflammatory pleural effusions. The other 79 patients had malignant pleural involvement. These groups are representative of the main types of pleural pathology. Results: The study found that all of the tumor markers, except for PIVKA-II (Protein induced by vitamin K absence-II), showed statistically significant differences between the malignant and non-malignant patient groups, with CAE (carcinoembryonic antigen) and CA19-9 showing the most notable differences. The Receiver Operating Characteristic (ROC) analysis revealed that CA72-4 had the best ability to distinguish between the two groups, while PIVKA was the weakest, with optimal cut-off values for all of the relevant tumor markers being derived using the Youden index. Conclusions: In conclusion, our study highlights the transformative potential of pleural fluid tumor markers as precise and minimally invasive resources for distinguishing malignant from non-malignant pleural effusions. These findings pave the way for improved diagnostic accuracy and personalized clinical management, addressing a critical gap in the care of patients with pleural pathologies.

Clinical value of combined detection of Carcinoembryonic Antigen and CA125 in the diagnosis of non-small cell lung cancer combined with Malignant Pleural Effusion

Objective

To investigate the clinical value of combined detection of carcinoembryonic antigen(CEA) and CA125 in the diagnosis of non-small cell lung cancer(NSCLC) combined with malignant pleural effusion.

Methods

This was retrospective research. Fifty-six NSCLC patients combined with malignant pleural effusion in Baoding No.1 Hospital, China, from January 2020 to January 2022 were recruited as the malignant group, and another 56 NSCLC patients combined with pleural effusion in the same period were recruited as the benign group. Pleural effusion and serum specimens were collected from both groups and their carcinoembryonic antigen (CEA), carbohydrate antigen 125(CA125) and SP70 antigen levels were measured respectively. The differences in index levels between the two groups were compared, and the value of the index in diagnosing NSCLC combined with malignant pleural effusion was analyzed.

Results

The positive rates of CEA, CA125 and SP70 antigen in pleural effusion were higher in the malignant group than in the benign group (p>0.05); The positive rates of CEA and CA125 in the malignant group were higher than those in the benign group (p>0.05), with no statistically significant difference between the two groups in the positive rates of SP70 antigen (p>0.05). ROC curve analysis revealed the value of serum CEA and CA12 in the diagnosis of NSCLC combined with malignant pleural effusion, while serum SP70 antigen had no diagnostic value (p>0.05).

Conclusion

The combined detection of CEA, CA125 and SP70 antigen boasts a higher diagnostic value for NSCLC-mediated pleural effusion, with higher diagnostic value than the combined detection of serum indexes.

Pleural CEA, CA-15-3, CYFRA 21-1, CA-19-9, CA-125 discriminating malignant from benign pleural effusions: Diagnostic cancer biomarkers

INTRODUCTION

There is a need for a rapid, accurate, less-invasive approach to distinguishing malignant from benign pleural effusions. We investigated the diagnostic value of five pleural tumor markers in exudative pleural effusions.

METHODS

By immunochemiluminescence assay, we measured pleural concentrations of tumor markers. We used the receiver operating characteristic curve analysis to assess their diagnostic values.

RESULTS

A total of 281 patients were enrolled. All tumor markers were significantly higher in malignant pleural effusions than benign ones. The area under the curve of carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 15-3, cytokeratin fragment 19 (CYFRA) 21-1, CA-19-9, and CA-125 were 0.81, 0.78, 0.75, 0.65, and 0.65, respectively. Combined markers of CEA + CA-15-3 and CEA + CA-15-3 + CYFRA 21-1 had a sensitivity of 87% and 94%, and specificity of 75% and 58%, respectively. We designed a diagnostic algorithm by combining pleural cytology with pleural tumor marker assay. CEA + CYFRA 21-1 + CA-19-9 + CA-15-3 was the best tumor markers panel detecting 96% of cytologically negative malignant pleural effusions, with a negative predictive value of 98%.

CONCLUSIONS

Although cytology is specific enough, it has less sensitivity in identifying malignant pleural fluids. As a result, the main gap is detecting malignant pleural effusions with negative cytology. CEA was the best single marker, followed by CA-15-3 and CYFRA 21-1. Through both cytology and suggested panels of tumor markers, malignant and benign pleural effusions could be truly diagnosed with an accuracy of about 98% without the need for more invasive procedures, except for the cohort with negative cytology and a positive tumor markers panel, which require more investigations.

Diagnosis of malignant pleural effusion with combinations of multiple tumor markers: A comparison study of five machine learning models

BACKGROUND

To evaluate the diagnostic value of combinations of tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 125, CA153, and CA19-9 in identifying malignant pleural effusion (MPE) from non-malignant pleural effusion (non-MPE) using machine learning, and compare the performance of popular machine learning methods.

METHODS

A total of 319 samples were collected from patients with pleural effusion in Beijing and Wuhan, China, from January 2018 to June 2020. Five machine learning methods including Logistic regression, extreme gradient boosting (XGBoost), Bayesian additive regression tree, random forest, and support vector machine were applied to evaluate the diagnostic performance. Sensitivity, specificity, Youden's index, and the area under the receiver operating characteristic curve (AUC) were used to evaluate the performance of different diagnostic models.

RESULTS

For diagnostic models with a single tumor marker, the model using CEA, constructed by XGBoost, performed best (AUC = 0.895, sensitivity = 0.80), and the model with CA153, also by XGBoost, showed the largest specificity 0.98. Among all combinations of tumor markers, the combination of CEA and CA153 achieved the best performance (AUC = 0.921, sensitivity = 0.85) in identifying MPE under the diagnostic model constructed by XGBoost.

CONCLUSIONS

Diagnostic models for MPE with a combination of multiple tumor markers outperformed the models with a single tumor marker, particularly in sensitivity. Using machine learning methods, especially XGBoost, could comprehensively improve the diagnostic accuracy of MPE.

Development and validation of a machine learning model for differential diagnosis of malignant pleural effusion using routine laboratory data

BACKGROUND

The differential diagnosis of malignant pleural effusion (MPE) and benign pleural effusion (BPE) presents a clinical challenge. In recent years, the use of artificial intelligence (AI) machine learning models for disease diagnosis has increased.

OBJECTIVE

This study aimed to develop and validate a diagnostic model for early differentiation between MPE and BPE based on routine laboratory data.

DESIGN

This was a retrospective observational cohort study.

METHODS

A total of 2352 newly diagnosed patients with pleural effusion (PE), between January 2008 and March 2021, were eventually enrolled. Among them, 1435, 466, and 451 participants were randomly assigned to the training, validation, and testing cohorts in a ratio of 3:1:1. Clinical parameters, including age, sex, and laboratory parameters of PE patients, were abstracted for analysis. Based on 81 candidate laboratory variables, five machine learning models, namely extreme gradient boosting (XGBoost) model, logistic regression (LR) model, random forest (RF) model, support vector machine (SVM) model, and multilayer perceptron (MLP) model were developed. Their respective diagnostic performances for MPE were evaluated by receiver operating characteristic (ROC) curves.

RESULTS

Among the five models, the XGBoost model exhibited the best diagnostic performance for MPE (area under the curve (AUC): 0.903, 0.918, and 0.886 in the training, validation, and testing cohorts, respectively). Additionally, the XGBoost model outperformed carcinoembryonic antigen (CEA) levels in pleural fluid (PF), serum, and the PF/serum ratio (AUC: 0.726, 0.699, and 0.692 in the training cohort; 0.763, 0.695, and 0.731 in the validation cohort; and 0.722, 0.729, and 0.693 in the testing cohort, respectively). Furthermore, compared with CEA, the XGBoost model demonstrated greater diagnostic power and sensitivity in diagnosing lung cancer-induced MPE.

CONCLUSION

The development of a machine learning model utilizing routine laboratory biomarkers significantly enhances the diagnostic capability for distinguishing between MPE and BPE. The XGBoost model emerges as a valuable tool for the diagnosis of MPE.

Diagnostic accuracy of pleural fluid to serum carcinoembryonic antigen ratio and delta value for malignant pleural effusion: findings from two cohorts

BACKGROUND

Pleural fluid (PF) carcinoembryonic antigen (CEA) is a widely used diagnostic marker for malignant pleural effusion (MPE). Recent studies revealed that PF to serum CEA was also a promising diagnostic parameter for MPE.

OBJECTIVE

We aimed to investigate whether PF to serum CEA ratio and delta CEA (PF minus serum CEA) provided added value to PF CEA in diagnosing MPE.

METHODS

Patients with pleural effusion in a retrospective cohort (BUFF) and a prospective cohort (SIMPLE) were included. The clinical characteristics of the patients were extracted from their medical records. The diagnostic value of CEA ratio and delta CEA was estimated by a receiver operating characteristics (ROC) curve, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

A total of 148 patients in the BUFF cohort and 164 patients in the SIMPLE cohort were enrolled. The BUFF cohort had 46 MPE patients and 102 benign pleural effusion (BPE) patients, and the SIMPLE cohort had 85 MPE patients and 79 BPE patients. In both cohorts, MPE patients had significantly higher PF CEA, serum CEA, CEA ratio, and delta CEA. The area under ROC curves (AUCs) of PF CEA, CEA ratio, and delta CEA were 0.78 (95% CI: 0.67-0.88), 0.80 (95% CI: 0.72-0.89) and 0.83 (95% CI: 0.75-0.91) in the BUFF cohort, and 0.89 (95% CI: 0.83-0.94), 0.86 (95% CI: 0.80-0.92), and 0.84 (95% CI: 0.78-0.91) in the SIMPLE cohort. The differences between the AUCs of PF CEA, CEA ratio, and delta CEA did not reach statistical significance. The continuous NRI and IDI of CEA ratio and delta CEA were <0.

CONCLUSION

CEA ratio and delta value cannot provide added diagnostic value to PF CEA. The simultaneous determination of serum and PF CEA should not be adopted in clinical practice.

Pleural fluid biochemical analysis: the past, present and future

Identifying the cause of pleural effusion is challenging for pulmonologists. Imaging, biopsy, microbiology and biochemical analyses are routinely used for diagnosing pleural effusion. Among these diagnostic tools, biochemical analyses are promising because they have the advantages of low cost, minimal invasiveness, observer independence and short turn-around time. Here, we reviewed the past, present and future of pleural fluid biochemical analysis. We reviewed the history of Light’s criteria and its modifications and the current status of biomarkers for heart failure, malignant pleural effusion, tuberculosis pleural effusion and parapneumonic pleural effusion. In addition, we anticipate the future of pleural fluid biochemical analysis, including the utility of machine learning, molecular diagnosis and high-throughput technologies. Clinical Chemistry and Laboratory Medicine (CCLM) should address the topic of pleural fluid biochemical analysis in the future to promote specific knowledge in the laboratory professional community.

Diagnostic Value of Six Tumor Markers for Malignant Pleural Effusion in 1,230 Patients: A Single-Center Retrospective Study

Background: The diagnostic value of tumor markers in pleural effusion (PE) and serum for malignant pleural effusion (MPE) is still in debate. This study aimed to evaluate the diagnostic value of six tumor markers in PE, serum, and the corresponding PE/serum (PE/S) ratio in distinguishing MPE from benign pleural effusion (BPE).

Methods: A total of 1,230 patients with PE (452 MPEs and 778 BPEs) were retrospectively included in the study. PE and serum levels of carcinoembryonic antigen (CEA), carbohydrate antigen 15-3 (CA15-3), carbohydrate antigen 125 (CA125), carbohydrate antigen 19-9 (CA19-9), cytokeratin 19 fragment (CYFRA 21-1), and neuron-specific enolase (NSE) were measured. The area under the curve (AUC) was used to assess the single and combined diagnostic values of the six tumor markers for MPE.

Results: The levels of the six tumor markers in PE, serum, and PE/S were significantly higher in MPE than that in BPE, except for serum CA125. PE CEA showed the highest AUC [0.890 (0.871–0.907)] at a cut-off value of 3.7 ng/ml compared to any single tumor marker using receiver operating characteristic (ROC) analysis. The specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of PE CEA were 74.1%, 95.5%, 90.5%, 86.4%, 16.47, and 0.27, respectively. The combination of PE CEA and serum CYFRA21-1 showed the best diagnostic performance with an AUC of 0.934 (sensitivity, 79.9%; specificity, 95.7%, PPV, 90.5; PLR, 17.35) among all two or three combinations. Besides, serum CYFRA21-1 was the best diagnostic tumor marker in distinguishing cytology-negative MPE from BPE at a cut-off value of 3.0 ng/ml.

Conclusion: PE CEA was the best diagnostic tumor marker in distinguishing MPE from BPE. Serum CYFRA21-1 was the best diagnostic tumor marker in distinguishing cytology-negative MPE from BPE. The combination of PE CEA and serum CYFRA21-1 could increase the diagnostic performance in distinguishing MPE from BPE and cytology-negative MPE from BPE.

Diagnostic accuracy of the cancer ratio for the prediction of malignant pleural effusion: evidence from a validation study and meta-analysis

OBJECTIVE

This study aimed to assess the diagnostic accuracy of serum LDH to pleural ADA ratio (cancer ratio, CR)for malignant pleural effusion (MPE) through an original study and meta-analysis.

METHODS

We retrospectively collected data from 145 patients with MPE and 117 cases of benign pleural effusions (BPE). The diagnostic performance of CR and a typical biomarker of MPE, carcinoembryonic antigen (CEA), were analysed using the receiver operating characteristic (ROC) curves and the area under the curve (AUC) as a measure of accuracy. The overall diagnostic accuracy of CR was summarised by a standard diagnostic meta-analysis.

RESULTS

Significantly higher CR and pleural CEA values were observed in the MPE patients than in the BPE patients. At a cut-off value of 14.97, CR showed high sensitivity (0.91), low specificity (0.67), and high AUC (0.85). The combination of CEA and CR increased the AUC to 0.98. The meta-analysis included seven studies involving 2,078 patients. The pooled values for sensitivity, specificity, positive/negative likelihood ratio, and diagnostic odds ratio of CR were 0.96, 0.88, 7.70, 0.05, and 169, respectively. The AUC of the summary ROC of CR was 0.98.

CONCLUSION

CR has a high diagnostic accuracy for predicting MPE, especially when used in combination with pleural CEA.

Assessment of the diagnostic value of CEA, CA125, and CRP and their cut-off point for discrimination of exudative pleural effusions

Pleural effusion is divided into exudative and transudative effusion, and the distinction between exudate and transudate requires multiple investigations of biochemical parameters and their comparison in pleural fluid and serum. This study aimed to assess the diagnostic value of CEA, CA125, and CRP and their cut-off point for discrimination of exudative pleural effusions. This epidemiological and cross-sectional study was performed on 50 patients aged between 18 to 90 years with the diagnosis of exudative pleural effusion referred to Imam Khomeini Hospital in Ahvaz in 2018 and 2019. Demographic and clinical information of patients were collected. The pleural effusion was diagnosed based on physical examination and chest radiography. Pleural effusion was confirmed by thoracentesis. A pleural fluid sample was taken from all patients, and the levels of CEA, CA125, and CRP markers were measured in the pleural fluid. Differentiation of transudate and exudate pleural effusions was performed using Light criteria. The mean CEA and CA125 level of pleural fluid were significantly higher, and the mean CRP level of pleural fluid was significantly lower in patients with malignant diagnoses (P <0.05). Cut-off value with highest sensitivity and specificity in differentiating types of exudative pleural effusions was obtained for CEA tumor marker (greater than 49.8), CA125 tumor marker (greater than 814.02), and CRP marker (less than 7.56). Also, in differentiating types of exudative pleural effusions, CEA tumor marker had sensitivity (89.03%) and specificity (78.42%); CA125 tumor marker had sensitivity (53.18%) and specificity (62.44%), and CRP marker had sensitivity (82.16%), and specificity (89.05%) were. Although the tumor markers had high specificity in the present study, the low sensitivity of some of these tumor markers reduced their diagnostic value. On the other hand, given the numerous advantages of tumor markers, such as low cost and non-invasive, combining them with another can increase the diagnostic value and accuracy.

Assessment of a panel of miRNAs in serum and pleural fluid for the differential diagnosis of malignant and benign pleural effusion

BACKGROUND

Differential diagnosis between malignant pleural effusion (MPE) and benign pleural effusion (BPE) remains a clinical challenge.

OBJECTIVE

The aim of the study is to assess the efficacy of the serum and pleural fluid (PF) miRNA panels in distinguishing MPE from BPE.

METHODS

Fourteen candidate miRNAs which were shown aberrant expression in lung cancer based on previous studies were tested by quantitative real-time PCR (qRT-PCR) in 20 MPE patients and 20 BPE patients. Significantly aberrantly expressed miRNAs were further assessed by qRT-PCR in all patients enrolled in this study. A receiver operating characteristic (ROC) curve was constructed, and the area under the ROC curve (AUC) was calculated to evaluated the diagnostic performance of the miRNAs.

RESULTS

miR-21, miR-29c and miR-182 were found to be significantly aberrantly expressed in the serum and PF of MPE patients. The AUCs for the combination of miR-21, miR-29c and miR-182 in serum and PF were 0.832 and 0.89 respectively in distinguishing MPE from infection-associated PE including tuberculous pleurisy and parapneumonia PE, and 0.866 and 0.919 respectively for differentiating MPE from heart failure-associated PE, which were superior to AUC of each individual miRNAs.

CONCLUSIONS

miR-21, miR-29c and miR-182 in serum and PF could be useful biomarkers for MPE of diagnosis.

The diagnostic value of CEA for lung cancer-related malignant pleural effusion in China: a meta-analysis

Objective: To accurately evaluate the diagnostic value of carcinoembryonic antigen (CEA) for malignant pleural effusion associated with lung cancer in the Chinese population.Methods: Three English databases, PubMed, Embase and Web of Science, and two Chinese databases, China National Knowledge Infrastructure (CNKI) and Wanfang Data, up to 5 November 2020, were searched. The literature on the diagnosis of lung cancer-related malignant pleural effusion by CEA in the Chinese population were collected. The data was analyzed by Stata15.0 software.Results: A total of 15 studies were included in the meta-analysis. The combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio were 0.80 (95% CI: 0.74-0.84), 0.92 (95% CI: 0.89-0.95), 10.46 (95% CI: 7.29-15.00), 0.22 (95% CI: 0.17-0.28), 47.26 (95% CI: 28.84-77.44), respectively . The area under the receiver operating characteristic curve was 0.93 (95% CI: 0.91-0.95). No significant publication bias was found (P > 0.05)Conclusion: CEA has anexcellent diagnostic value for patients with lung cancer-related malignant pleural effusion in the Chinese population.

Development of risk prediction models for lung cancer based on tumor markers and radiological signs

Background

Accurate prediction of malignancy risk for pulmonary lesions with pleural effusion improves early diagnosis of lung cancer. This study aimed to develop and validate a model to predict lung cancer.

Methods

Clinical data of 536 patients with pulmonary diseases were collected. The risk factors were identified by regression analysis. Three prediction models were developed. The predictive performances of the models were measured by the area under the curves (AUCs) and calibrated with 1000 bootstrap samples to minimize the over‐fitting bias. The net benefits of the models were evaluated by decision curve analysis. Finally, a separate cohort of 134 patients was used to validate the models externally.

Results

Seven independent risk factors were identified from 18 clinical variables, which included the pleural fluid carcinoembryonic antigen (CEA), serum cytokeratin‐19 fragment (CYFRA 21‐1), the ratio of CEA in the pleural fluid to serum, extrathoracic cancer history (>5 years), tumor size, vessel convergence, and lobulation. The AUCs of the three models were 0.976, 0.927, and 0.944 in the training set and 0.930, 0.845, and 0.944 in the external set, respectively. The accuracies of the three models were 89.6%, 81.4%, and 88.8%. Model 1 showed the best iteration fit (R² = 0.84, 0.68, and 0.73) and a higher net benefit on decision curve analysis when compared to the other two models.

Conclusion

The advantageous model could assess the risk of lung cancer in patients with pleural effusion and act as a useful tool for early identification of lung cancer.

Salivary microRNAs show potential as biomarkers for early diagnosis of malignant pleural effusion

Background

Malignant pleural effusion (MPE) is a common medical problem caused by multiple malignancies, especially lung cancers, and always comes along with a poor outcome. Early detection and diagnosis are important for improving the prognosis in patients with MPE. Salivary microRNAs (miRNAs) may represent a relatively convenient way for diagnosing MPE. We investigated the characteristics of salivary miRNAs of MPE patients, benign pleural effusion (BPE) patients, patients with a malignant tumor but without pleural effusion (MT), and healthy controls (HCs). We believe that they may show potential as a non-invasive and convenient biomarker for diagnosing MPE.

Methods

From January 1, 2019, to July 1, 2019, 57 MPE patients, 33 BPE patients, 50 MT patients, and 49 HCs were enrolled. To select candidate biomarkers, in the discovery phase, the salivary miRNA profiles were detected in three MPE patients and three HCs. Then, qPCR was used in the validation phase with 54 MPE patients, 33 BPE patients, 50 MT patients, and 46 HCs to assay the selected miRNAs.

Results

hsa-miR-4484 and hsa-miR-3663-3p were identified as potential biomarkers to diagnose MPE patients, with areas under the curve (AUC) of 0.768 and 0.666, respectively. The diagnostic efficacy was higher when the combination of both miRNAs was used, with an AUC of 0.802. No correlation was found between the volume of MPE and the expression of salivary miRNAs.

Conclusions

This study reports the characterization of salivary miRNAs collected from MPE patients. A combination of hsa-miR-4484 and hsa-miR-3663-3p showed potential discriminatory power for MPE detection, and it may be helpful for the early diagnosis of MPE, i.e., before the pleural effusion volume is too large.

Diagnostic value of CD206+CD14+ macrophages in diagnosis of lung cancer originated malignant pleural effusion

Background

Pleural effusions are common complications of various diseases. Patients with malignant pleural effusion (MPE) usually face poor prognosis and short life expectancy. Discriminating between MPE and benign pleural effusion remains to be difficult. The aim of our current study was to evaluate whether CD206⁺CD14⁺ macrophages could be a diagnostic biomarker for MPE.

Methods

The percentages of CD14⁺, CD86⁺CD14⁺ and CD206⁺CD14⁺ macrophages in pleural effusions were determined by flow cytometry in 34 patients with MPE and 26 with benign pleural effusion, and their diagnostic performances were evaluated by receiver operating characteristic (ROC) curves.

Results

The percentages of CD14⁺, CD86⁺CD14⁺ and CD206⁺CD14⁺ macrophages were remarkably higher in MPE than in benign pleural effusion (all P<0.05). With a cutoff value of 39.8%, a high sensitivity of 88.2% and high specificity of 100.0% were found in CD206⁺CD14⁺ macrophages to diagnose MPE. The area under the curve, positive predictive value and negative predictive value of CD206⁺CD14⁺ macrophages were 0.980 (95% CI, 0.905 to 0.999), 100.0 (88.4 to 100.0) and 86.7 (69.3 to 96.2), respectively. The diagnostic performance of CD206⁺CD14⁺ macrophages was more accurate than those of CD14⁺ and CD86⁺CD14⁺ macrophages.

Conclusions

CD206⁺CD14⁺ macrophages could be used to discriminate MPE from benign pleural effusion.

Ratio of carcinoembryonic antigen in pleural fluid and serum for the diagnosis of malignant pleural effusion

Background

Tumour markers in pleural fluid and their diagnostic value are subject to debate. Although there are several studies on this topic, standardized cut-off values do not exist. In this study we investigated the potential of a ratio of carcinoembryonic antigen (CEA) in pleural fluid and serum, serving as an individual marker for pleural cancer manifestation.

Methods

A total of 201 consecutive patients with unclear pleural effusion were included in the study; 98 were diagnosed with malignant pleural effusion and 103 had an effusion due to other, benign reasons. CEA levels in pleural fluid and serum were measured.

Results

By using receiver operating characteristics analysis, at the cut-off of 1.0, the CEA ratio showed a specificity of 92% and sensitivity of 85%, with a positive predictive value of 91% and a negative predictive value of 87%. These results are higher than in previous investigations on different pleural tumour markers and their combination.

Conclusions

The CEA ratio is a useful tool in predicting pleural carcinosis. Elevated results in cytology-negative patients should lead to further investigations, such as repeated cytological examination or thoracoscopy.

Diagnostic value of soluble mesothelin-related peptides in pleural effusion for malignant pleural mesothelioma: An updated meta-analysis

BACKGROUND

Soluble mesothelin-related peptide (SMRP) is a widely studied tumor marker for diagnosing malignant pleural mesothelioma (MPM). This study discussed the diagnostic value of SMRPs in pleural effusion (PE) for MPM.

METHODS

Medline, Embase, Web of Science, and Cochrane library system were systematically searched on the data of SMRPs in PE for MPM diagnosis. Pooled diagnostic sensitivity, specificity, and symmetric receiver operating characteristic curve were calculated.

RESULTS

Thirteen studies fulfilled the inclusion criteria and a total of 3359 cases including 759 MPM cases, 1061 non-MM (malignant mesothelioma) malignant PE, and 1539 benign PE were brought into this meta-analysis. The pooled results of SMRPs in PE for diagnosing MPM were as follows: sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.68 (95% confidence interval [CI]: 0.64-0.72), 0.91 (95% CI: 0.86-0.94), 7.8 (95% CI: 5.0-12.0), 0.35 (95% CI: 0.31-0.40), and 22 (95% CI: 14-35), respectively. The area under the summary receiver operating characteristic curves (AUC) was 0.75 (95% CI: 0.72-0.80). Subgroup analyzes revealed that the AUC of cohort group using histological diagnosis could be improved to 0.86 (95% CI: 0.83, 0.89). The Deek's funnel plot asymmetry test showed no publication bias.

CONCLUSION

Although the sensitivity of SMRPs was low, PE-SMRPs can be a good indicator of the existence of MPM.

Diagnostic value of acid phosphatases (ACP) in differentiating reactive mesothelial cells from cancer cells in the body fluid effusions

Background

The cytological diagnosis of a malignant epithelial tumor, i.e., a cancer cell in the body fluid effusions is usually made by cytomorphological examination alone; however, diagnostic challenges can occur when the cancer cells are rare or cytological atypia is minimal. Morphological similarity between the cancer and the reactive mesothelial cell is the most common problem in establishing a clear diagnosis. The aim of this study is to investigate whether the cocktail acid phosphatases (ACP) special staining will be a useful tumor marker in differentiation of the reactive mesothelial cells from the cancer cells in the body fluid effusions.

Methods

The cocktail ACP special staining was performed on 212 body fluid effusion samples, which included 128 pleural effusions, 69 ascites, and 15 pericardial effusions.

Results

The mesothelial cells were cocktail ACP positive in 84 out of 84 benign effusion cases, and the sensitivity and the specificity were 100% for the benign effusions which including pleural effusions, ascites, and pericardial effusions. On the other hand, 122 out of 128 cancer cases were cocktail ACP negative, indicating that the sensitivity of using the cocktail ACP staining to rule out the malignant effusions was 95.3%. Thus, the cocktail ACP staining is an excellent marker with high sensitivity and specificity to distinguish the carcinoma from the reactive mesothelial cells in the body fluid effusions.

Conclusions

Our finding provided a new tool for cytopathologists in diagnosing the body fluid effusion that could impact clinical decision making.

Diagnosing malignant pleural effusion using clinical and analytical parameters

BACKGROUND

Malignant pleural effusion (MPE) is common and diagnosis is often problematic. A cancer ratio (serum lactate dehydrogenases: pleural adenosine deaminase ratio) has been proposed for diagnosing MPE. However, the usefulness of this "cancer ratio" and the clinical-radiological criteria for diagnosing MPE has not been clearly determined to date. The aim of this study was to assess the performance of those parameters in the diagnosis of MPE.

METHODS

We analyzed 240 patients including 120 with MPE and 120 with non-MPE (93 tuberculous and 27 parapneumonic). Patients were divided into two groups: MPE and non-MPE (eg, tuberculous and parapneumonic). We constructed two predictive models to assess the probability of MPE: (a) clinical-radiological data only and (b) a combination of clinical-radiological data, the cancer ratio, and the carcinoembryonic antigen (CEA). The performances of the predictive models were assessed using receiver operating characteristic (ROC) curves and by examining the calibration.

RESULTS

The area under the ROC curves for model 1 and model 2 were excellent, 0.936 and 0.998, respectively. The overall diagnostic accuracies for model 1 and model 2 were 87.5% and 98.8%, respectively.

CONCLUSION

The results confirm that both models achieved a high diagnostic accuracy for MPE; however, model 2 was superior with the addition of its simplicity of use in daily practice. This model should be applied to determine which patients with a pleural effusion of unknown origin would not benefit from further invasive procedures.