Diagnostic value of carcinoembryonic antigen in malignant pleural effusion: a meta-analysis

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.

Diagnosis of malignant body fluids via cancer-universal methylation in cell-free DNA

BACKGROUNDDifferentiating malignant from nonmalignant body fluids remains a clinical challenge because of the unsatisfying performance of conventional cytology. We aimed to improve the sensitivity and ubiquity of cancer cell detection by assaying universal cancer-only methylation (UCOM) markers in supernatant cell-free DNA (cfDNA).METHODSAn observational prospective cohort including 1,321 nonmalignant and malignant body fluids of multiple cancers was used to develop and validate a cfDNA UCOM methylation diagnostic assay. All samples were divided into 2 portions for cytology and supernatant cfDNA methylation analysis.RESULTSThe significant hypermethylation of a potentially novel UCOM marker, TAGMe, together with the formerly reported PCDHGB7, was identified in the cfDNA of malignant body fluid samples. The combined model, cell-free cancer-universal methylation (CUE), was developed and validated in a prospective multicancer cohort with markedly elevated sensitivity and specificity, and was further verified in a set containing additional types of malignant body fluids and metastases. In addition, it remained hypersensitive in detecting cancer cells in cytologically negative malignant samples.CONCLUSIONcfDNA methylation markers are robust in detecting tumor cells and are applicable to diverse body fluids and tumor types, providing a feasible complement to current cytology-based diagnostic analyses.TRIAL REGISTRATIONThis study was registered at Chictr.org.cn (ChiCTR2200060532).FUNDINGNational Natural Science Foundation of China (32270645, 31872814, 32000505, 82170088), the National Key R&D Program of Ningxia Hui Autonomous region (2022BEG01003), Shanghai Municipal Key Clinical Specialty (shslczdzk02201), Science and Technology Commission of Shanghai Municipality (20DZ2261200, 20DZ2254400), and Major Special Projects of Basic Research of Shanghai Science and Technology Commission (18JC1411101).

Sonography of the pleura

The CME review presented here is intended to explain the significance of pleural sonography to the interested reader and to provide information on its application. At the beginning of sonography in the 80 s of the 20th centuries, with the possible resolution of the devices at that time, the pleura could only be perceived as a white line. Due to the high impedance differences, the pleura can be delineated particularly well. With the increasing high-resolution devices of more than 10 MHz, even a normal pleura with a thickness of 0.2 mm can be assessed. This article explains the special features of the examination technique with knowledge of the pre-test probability and describes the indications for pleural sonography. Pleural sonography has a high value in emergency and intensive care medicine, preclinical, outpatient and inpatient, in the general practitioner as well as in the specialist practice of pneumologists. The special features in childhood (pediatrics) as well as in geriatrics are presented. The recognition of a pneumothorax even in difficult situations as well as the assessment of pleural effusion are explained. With the high-resolution technology, both the pleura itself and small subpleural consolidations can be assessed and used diagnostically. Both the direct and indirect sonographic signs and accompanying symptoms are described, and the concrete clinical significance of sonography is presented. The significance and criteria of conventional brightness-encoded B-scan, colour Doppler sonography (CDS) with or without spectral analysis of the Doppler signal (SDS) and contrast medium ultrasound (CEUS) are outlined. Elastography and ultrasound-guided interventions are also mentioned. A related further paper deals with the diseases of the lung parenchyma and another paper with the diseases of the thoracic wall, diaphragm and mediastinum.

Differential Diagnosis of Pleural Effusion Using Machine Learning

Rationale: Differential diagnosis of pleural effusion is challenging in clinical practice. Objectives: We aimed to develop a machine learning model to classify the five common causes of pleural effusions. Methods: This retrospective study collected 49 features from clinical information, blood, and pleural fluid of adult patients who underwent diagnostic thoracentesis between October 2013 and December 2018. Pleural effusions were classified into the following five categories: transudative, malignant, parapneumonic, tuberculous, and other. The performance of five different classifiers, including multinomial logistic regression, support vector machine, random forest, extreme gradient boosting, and light gradient boosting machine (LGB), was evaluated in terms of accuracy and area under the receiver operating characteristic curve through fivefold cross-validation. Hybrid feature selection was applied to determine the most relevant features for classifying pleural effusion. Results: We analyzed 2,253 patients (training set, n = 1,459; validation set, n = 365; extra-validation set, n = 429) and found that the LGB model achieved the best performance in both validation and extra-validation sets. After feature selection, the accuracy of the LGB model with the selected 18 features was equivalent to that with all 49 features (mean ± standard deviation): 0.818 ± 0.012 and 0.777 ± 0.007 in the validation and extra-validation sets, respectively. The model's mean area under the receiver operating characteristic curve was as high as 0.930 ± 0.042 and 0.916 ± 0.044 in the validation and extra-validation sets, respectively. In our model, pleural lactate dehydrogenase, protein, and adenosine deaminase levels were the most important factors for classifying pleural effusions. Conclusions: Our LGB model showed satisfactory performance for differential diagnosis of the common causes of pleural effusions. This model could provide clinicians with valuable information regarding the major differential diagnoses of pleural diseases.

Age affects the diagnostic accuracy of the cancer ratio for malignant pleural effusion

BACKGROUND AND OBJECTIVE

Cancer ratio (CR), which is defined as serum lactate dehydrogenase (LDH) to pleural fluid adenosine deaminase (ADA) ratio, has been reported to be a useful diagnostic marker for malignant pleural effusion (MPE). Whether its diagnostic accuracy is affected by age remains unknown. This study aimed to investigate the effects of age on the diagnostic accuracy of CR.

METHODS

The participants in this study were from a prospective cohort (SIMPLE cohort, n = 199) and a retrospective cohort (BUFF cohort, n = 158). All participants were patients with undiagnosed pleural effusion (PE). We used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CR. The effect of age on the diagnostic accuracy of CR was investigated by adjusting the upper limit of age for participant enrolment.

RESULTS

Eighty-eight MPE patients were verified in the SIMPLE cohort, and thirty-five MPE patients were verified in the BUFF cohort. The AUCs of CR in the SIMPLE and BUFF cohorts were 0.60 (95% CI: 0.52-0.68) and 0.63 (95% CI: 0.54-0.71), respectively. In both cohorts, the AUCs of CR decreased with the advancement of age.

CONCLUSION

Age can affect the diagnostic accuracy of CR for MPE. CR has limited diagnostic value in older patients.

KEY MESSAGE

Cancer ratio is a promising diagnostic marker for malignant pleural effusion. This study revealed that its diagnostic accuracy decreased in older patients. Its diagnostic accuracy is overestimated by previous studies using tuberculosis and pneumonia patients as controls.

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.

DNA image cytometry ploidy analysis technique improves the detection rate of pleural effusion cytology

OBJECTIVE

To explore the clinical diagnostic value of DNA image cytometry (DNA-ICM) ploidy analysis in malignant pleural effusion cancer screening, this study analyzed the effect of exfoliated cell smears (ECSs), cell blocks (CBs), and immunochemistry.

METHOD

A total of 830 cases of pleural effusion were considered for the DNA-ICM ploidy analysis. The ECSs were centrifuged, the CBs were formed, and the DNA-ICM ploidy analysis was carried out in the diagnosis of malignant pleural effusion. Immunochemistry and biopsy was applied to differentiate between benign and malignant pleural effusion and to determine the source of the latter. The sensitivity and specificity differences between the three methods alone and in combination were compared.

RESULTS

The sensitivity of the DNA-ICM, ECS, and CB methods was 96.28%, 94.93%, and 95.95%, respectively, and the specificity of each method was 86.52%, 87.08%, and 86.14%, respectively. The sensitivity and specificity of the combined diagnosis method were 99.32% and 75.09%, respectively. Among the 22 cases diagnosed as positive in the DNA-ICM ploidy analysis but negative in the ECS and CB analyses, four cases were diagnosed as positive by comprehensive clinical diagnosis.

CONCLUSION

The sensitivity and specificity of DNA-ICM ploidy analysis are high; the positive detection rate of pleural fluid cytology is effectively increased, and the missed detection rate of cell pathologies is effectively reduced. The combination of the three methods significantly improves the specificity and sensitivity of the diagnosis of malignant pleural effusion, and immunochemistry with CBs can be used to accurately analyze the primary tumor site.

DNA Methylation Analysis of the SHOX2 and RASSF1A Panel Using Cell-Free DNA in the Diagnosis of Malignant Pleural Effusion

Objectives

The differential diagnosis of pleural effusion (PE) is a common but major challenge in clinical practice. This study aimed to establish a strategy based on a PE-cell-free DNA (cfDNA) methylation detection system for the differential diagnosis of malignant pleural effusion (MPE) and benign pleural effusion (BPE).

Methods

A total of 104 patients with PE were enrolled in this study, among which 50 patients had MPE, 9 malignant tumor patients had PE of indefinite causes, and the other 45 patients were classified as benign controls. The methylation status of short stature homeobox 2 (SHOX2) and RAS association domain family 1, isoform A (RASSF1A) was detected using PE-cfDNA specimens by real-time fluorescence quantitative PCR. Total methylation (TM) was defined as the combination of the methylation levels of SHOX2 and RASSF1A. The electrochemiluminescence immunoassay was applied to evaluate the levels of multiple serum tumor markers.

Results

The PE-cfDNA methylation status of either SHOX2 or RASSF1A was much higher in MPE samples than in benign controls. The combination of SHOX2 and RASSF1A methylation in PE yielded a diagnostic sensitivity of 96% and a specificity of 100%, respectively. When compared with the corresponding serum tumor marker detection results, TM showed the highest diagnostic efficiency (AUC = 0.985). Furthermore, the combination of the SHOX2 and RASSF1A methylation panels using PE-cfDNA could apparently improve the differential diagnostic efficacy of BPE and MPE and could help compensate for the deficiency of cytology.

Conclusions

Our results indicated that SHOX2 and RASSF1A methylation panel detection could accurately classify BPE and MPE diseases and showed better diagnostic performance than traditional serum parameters. The SHOX2 and RASSF1A methylation detection of PE-cfDNA could be a potentially effective complementary tool for cytology in the process of differential diagnosis. In summary, PE-cfDNA could be used as a promising non-invasive analyte for the auxiliary diagnosis of MPE.

Value of human epididymis secretory protein 4 in differentiating malignant from benign pleural effusion: an analysis of two cohorts

BACKGROUND

Lung cancer is the most common cause of malignant pleural effusion (MPE). Serum human epididymis secretory protein 4 (HE4) is a useful diagnostic marker for lung cancer.

OBJECTIVE

This study aimed to evaluate the diagnostic accuracy of pleural fluid HE4 for MPE.

DESIGN

A prospective, double-blind diagnostic test accuracy study.

METHODS

Patients with undiagnosed pleural effusion were enrolled in two cohorts (Hohhot and Changshu). Electrochemiluminescence immunoassay was used to detect pleural fluid HE4. The diagnostic accuracy of HE4 was evaluated by a receiver operating characteristic (ROC) curve, and the net benefit of HE4 was assessed by a decision curve analysis (DCA).

RESULTS

A total of 66 MPEs and 86 benign pleural effusions (BPEs) were enrolled in the Hohhot cohort. In the Changshu cohort, 26 MPEs and 32 BPEs were enrolled. In both cohorts, MPEs had significantly higher pleural fluid HE4 than BPEs. The area under the ROC curve (AUC) of HE4 was 0.73 (95% CI: 0.64-0.81) in the Hohhot cohort and 0.79 (95% CI: 0.67-0.91) in the Changshu cohort. At a threshold of 1300 pmol/L, HE4 had sensitivities of 0.44 (95% CI: 0.33-0.56) in the Hohhot cohort and 0.54 (95% CI: 0.35-0.73) in the Changshu cohort. The corresponding specificities were 0.90 (95% CI: 0.83-0.95) in the Hohhot cohort and 0.94 (95% CI: 0.84-1.00) in the Changshu cohort. In subgroup analyses, HE4 had an AUC (95% CI) of 0.78 (0.71-0.85) in exudates and an AUC of 0.69 (0.57-0.81) in patients with negative effusion cytology. The DCA revealed that HE4 determination had a net benefit in both cohorts.

CONCLUSION

Pleural fluid HE4 has moderate diagnostic accuracy for MPE and has net benefit in pleural effusion patients with unknown etiology.

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.

Evaluation of serum and pleural levels tumor M2-pyruvate kinase in lung cancer patients with pleural effusion

Objective

To evaluate the diagnostic value of tumor M2-pyruvate kinase (TuM2-PK) and carcinoembryonic antigen (CEA) levels in both pleural effusion and serum in the differential diagnosis of benign and malignant pleural effusion.

Methods

This prospective study was conducted among 80 patients with benign pleural effusion (BPE group) and 125 patients with malignant pleural effusion associated with lung cancer (MPE group). The levels of TuM2-PK and CEA were measured by using sandwich enzyme-linked immunosorbent assay and electrochemiluminescence. The receiver-operating characteristic curve (ROC) analysis was used to confirm the cutoff value to evaluate the diagnostic efficiency of TuM2-PK and CEA.

Results

The TuM2-PK and CEA levels in pleural effusion and serum, and their ratio (P/S) were higher in MPE group than that in BPE group (P < 0.05). In pleural effusion and serum, the diagnostic efficiency of combined TuM2-PK and CEA for MPE was superior to either single detection.

Conclusions

The combined detection of TuM2-PK and CEA has a high sensitivity for diagnosis of MPE and might provide method for rapid and accurate diagnosis of patients.

A Case of Pneumonia Masking Pleural Malignancy

The invasion of the pleural membrane by a malignant pleural tumor can lead to the production of malignant pleural effusion (MPE), resulting in the symptoms of dyspnea, and some patients have cough, sputum and other symptoms, which are easily confused with pneumonia. In this case, the initial diagnosis of the patient is pneumonia, and the final diagnosis is pneumonia combined with pleural malignancy. Therefore, if the patient has unexplained symptoms of bloody pleural effusion, it is necessary to examine for malignant tumors and should actively perform thoracentesis and drainage, look for malignant cells in the pleural effusion cell precipitation, evaluate the nature of pleural effusion, conduct pleural biopsy tissue examination, and determine the type and source of lung malignancy by the combined application of cell block technology and immunohistochemistry. Take the cytological examination results in pleural effusion seriously, and finally, surgical or immunotherapy can be performed.

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.

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.

Pleural biomarkers in diagnostics of malignant pleural effusion: a narrative review

Although cytology and pleural biopsy of pleural effusion (PE) are the gold standards for diagnosing malignant pleural effusion (MPE), these tools’ diagnostic accuracy is plagued by some limitations such as low sensitivity, considerable inter-observer variation and invasiveness. The assessment of PE biomarkers may hence be seen as an objective and non-invasive diagnostic alternative in MPE diagnostics. In this review, we summarize the characteristics and diagnostic accuracy of available PE biomarkers, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), carbohydrate antigens 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 15-3 (CA15-3), a fragment of cytokeratin 19 (CYFRA 21-1), chitinase-like proteins (CLPs), vascular endothelial growth factor (VEGF) and its soluble receptor, endostatin, calprotectin, cancer ratio, homocysteine, apolipoprotein E (Apo-E), B7 family members, matrix metalloproteinase (MMPs) and tissue-specific inhibitors of metalloproteinases (TIMPs), reactive oxygen species modulator 1 (Romo1), tumor-associated macrophages (TAMs) and monocytes, epigenetic markers (e.g., cell-free microRNA and mRNA). We summarized the evidence from systematic review and meta-analysis for traditional tumor markers’ diagnostic accuracy. According to the currently available evidence, we conclude that the traditional tumor markers have high specificity (around 0.90) but low sensitivity (around 0.50). The diagnostic accuracy of novel tumor markers needs to be validated by further studies. None of these tumor biomarkers would have sufficient diagnostic accuracy to confirm or exclude MPE when used alone. A multi-biomarker strategy, also encompassing the use of artificial intelligence algorithms, may be a valuable perspective for improving the diagnostic accuracy of MPE.

Comparative Assessment of Two Strategies for Interpreting Tumor Markers in Ascitic Effusions

BACKGROUND/AIM

There are two strategies for the interpretation of tumor markers (TM) in fluid effusions: i) high cut-off and ii) fluid/serum ratio (F/S) and low cut-off. The objective of this study is to compare these two strategies and to determine whether diagnostic accuracy improves by the identification of possible false positives using Adenosine deaminase (ADA), C reactive protein (CRP) and % of polymorphonuclear cells (%PN).

PATIENTS AND METHODS

We studied 157 ascitic fluids, 74 of which were malignant. ADA, CRP and %PN were determined in ascitic fluid, and Carcinoembryonic antigen (CEA), Cancer antigen 72-4 (CA72-4), Cancer antigen CA19-9 and Cancer antigen 15-3 (CA15-3) in both fluid and serum.

RESULTS

The strategy of high cut-off showed 59.5% sensitivity at 100% specificity. The F/S strategy showed 75.7% sensitivity at 95.2% specificity. Subclassifying cases with ADA, CRP and %PN negative showed 67.5% sensitivity at 100% specificity for high cut-off and for the F/S strategy was 81.7% sensitivity at 98.7% specificity.

CONCLUSION

The strategy of F/S with negative ADA, CRP and %PN allow the best interpretation for TM in the ascitic fluid.

Analysis of tumor markers in pleural effusion and serum to verify the correlations between serum tumor markers and tumor size, TNM stage of lung adenocarcinoma

BACKGROUND

The study of tumor markers (TM) in pleural effusion (PE) was not extensive.

METHODS

TM in PE and serum were analyzed to determine whether TM was expressed in intrathoracic and extrathoracic tissues. To further verify the correlations between serum TM and tumor size, TNM stage of lung adenocarcinoma.

RESULTS

Serum AFP was not correlated with tumor size, T stage, N stage, and M stage (P > .05). Serum CEA, serum CA125, serum CA15-3 were positively correlated with tumor size, T stage, N stage, M stage (P < .05). Serum CA19-9 was not significantly correlated with tumor size and T stage (P > .05), but was positively correlated with N stage and M stage (P < .05). The levels of PE CEA, PE CA125, PE CA15-3 were higher than those of serum CEA, serum CA125, serum CA15-3 (all P < .05). The level of PE AFP was lower than that of serum AFP (P < .05). The level of PE CA19-9 was not significantly different from that of serum CA19-9 (P > .05). The positive rates of PE CEA and PE CA125 were higher than those of serum CEA and serum CA125 (P < .05). The positive rates of PE AFP, PE CA15-3, PE CA19-9 were not significantly different from those of serum AFP, serum CA15-3, serum CA19-9 (P > .05).PE CEA, PE CA125, PE CA15-3 were moderately positively correlated with serum CEA, serum CA125, serum CA15-3, respectively (r = 0.597; r = 0.46; r = 0.583, all P < .05). However, PE AFP and PE CA19-9 were very strongly positively correlated with serum AFP and serum CA19-9, respectively (r = 0.888; r = 0.874, all P < .05).

CONCLUSION

The expression characteristics of TM in PE and serum supported the correlations between serum TM and tumor size, TNM stage of lung adenocarcinoma.

Diagnostic accuracy of cancer ratio for malignant pleural effusion: a systematic review and meta-analysis

Background

Several studies have investigated the diagnostic accuracy of serum lactate dehydrogenase (LDH) to pleural fluid adenosine deaminase ratio (cancer ratio, CR) for malignant pleural effusion (MPE), but the results were various. Therefore, we performed this systematic review and meta-analysis to ascertain the diagnostic accuracy of CR for MPE.

Methods

The PubMed and EMBASE databases were searched up to 7 June, 2019 to identify publications concerning diagnostic accuracy of CR for MPE. The sensitivities and specificities of CR in included studies were pooled with a bivariate model. A summary receiver operating characteristic (sROC) curve was used to estimate the global diagnostic accuracy of CR. Quality of the included studies was assessed with the revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2).

Results

Finally, five studies with 596 MPE patients and 863 benign pleural effusion (BPE) patients were included in this systematic review and meta-analysis. The pooled sensitivity and specificity of CR were 0.97 (95% CI: 0.92-0.99) and 0.89 (0.69-0.97), respectively. The area under sROC curve was 0.98 (95% CI: 0.97-0.99). The major design weaknesses of the included studies were patients selection and partial verification bias.

Conclusions

CR has high diagnostic accuracy for MPE. Considering the design weaknesses of available studies, further studies with rigorous design are needed to further validate the findings of this meta-analysis.

The diagnostic value of pleural fluid homocysteine in malignant pleural effusion

Background

Pleural fluid homocysteine (HCY) can be useful for diagnosis of malignant pleural effusion (MPE). There are no published studies comparing the diagnostic accuracy of HCY with other tumour markers in pleural fluid for diagnosis of MPE. The aim was to compare the accuracy of HCY with that of carcinoembryonic antigen (CEA), cancer antigen (CA) 15.3, CA19.9 and CA125 in pleural fluid and to develop a probabilistic model using these biomarkers to differentiate benign (BPE) from MPE.

Methods

Patients with pleural effusion were randomly included. HCY, CEA, CA15.3, CEA19.9 and CA125 were quantified in pleural fluid. Patients were classified into two groups: MPE or BPE. By applying logistic regression analysis, a multivariate probabilistic model was developed using pleural fluid biomarkers. The diagnostic accuracy was determined by receiver operating characteristic (ROC) curves and calculating the area under the curve (AUC).

Results

Population of study comprised 133 patients (72 males and 61 females) aged between 1 and 96 years (median = 70 years), 81 BPE and 52 MPE. The logistic regression analysis included HCY (p<0.0001) and CEA (p = 0.0022) in the probabilistic model and excluded the other tumour markers. The probabilistic model was: HCY+CEA = Probability(%) = 100×(1+e^-z)^-1, where Z = 0.5471×[HCY]+0.3846×[CEA]–8.2671. The AUCs were 0.606, 0.703, 0.778, 0.800, 0.846 and 0.948 for CA125, CA19.9, CEA, CA15.3, HCY and HCY+CEA, respectively.

Conclusions

Pleural fluid HCY has higher accuracy for diagnosis of MPE than CEA, CA15.3, CA19.9 and CA125. The combination of HCY and CEA concentrations in pleural fluid significantly improves the diagnostic accuracy of the test.

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 and prognostic values of endothelial-cell-specific molecule-1 with malignant pleural effusions in patients with non-small cell lung cancer

Over-expressed endothelial-cell-specific molecule-1 (ESM-1) in tumor vascular endothelium contributes to tumor angiogenesis, metastasis, and poor prognosis. However, the content of ESM-1 in pleural effusion is unclear. A retrospective study was carried out to investigate the diagnostic and prognostic values of ESM-1 with malignant pleural effusions in patients with non-small cell lung cancer (NSCLC). ESM-1 levels in malignant pleural effusion (MPE) from 70 patients with NSCLC and 50 cases of benign pleural effusion (BPE) were measured using enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curve was calculated to assess the diagnostic value of ESM-1. Survival curves were performed by Kaplan-Meier method and survival characteristics were compared by log-rank test. Univariable and multivariate Cox proportional hazards model were carried out to analysis the significance of different prognostic factors for overall survival (OS). ESM-1 levels were significantly higher in MPE than those in BPE (p < 0.001). By ROC curve analysis, with a cutoff level of 19.58 ng/ml, the accuracy, sensitivity, and specificity for ESM-1 diagnosis MPE were 82.5%, 81.4%, and 84.0%, respectively. Moreover, NSCLC patients with pleural fluid ESM-1 levels below 19.58 ng/ml had significant longer OS than those patients with higher levels (22.09 months vs. 11.49 months, p = 0.003). Multivariate survival analysis showed that high MPE ESM-1 level was an independent prognostic factor (HR, 1.007; p = 0.039) for the OS of NSCLC patients. This study showed that ESM-1 level in pleural effusion could be a potential diagnostic and prognostic marker in NSCLC patients with MPE.

Diagnostic Significance of Measuring Vascular Endothelial Growth Factor for the Differentiation between Malignant and Tuberculous Pleural Effusion

Malignancy and tuberculosis are common causes of lymphocytic exudative pleural effusion. However, it is occasionally difficult to differentiate malignant pleural effusion from tuberculous pleural effusion. Vascular endothelial growth factor (VEGF) is a critical cytokine in the pathogenesis of malignant pleural effusion. Endocan is a dermatan sulfate proteoglycan that is secreted by endothelial cells. Importantly, endocan mediates the vascular growth-promoting action of VEGF. The aim of this study was to evaluate the diagnostic significance of VEGF and endocan in pleural effusion. We thus measured the levels of VEGF and endocan in the pleural effusion and serum samples of patients with lung cancer (n = 59) and those with tuberculosis (n = 32) by enzyme-linked immunosorbent assay. Lung cancer included 40 cases of adenocarcinoma, 13 of squamous cell carcinoma, and 6 of small cell carcinoma. Pleural effusion VEGF levels were significantly higher in the malignant group than in the tuberculosis group (2,091.47 ± 1,624.80 pg/mL vs. 1,291.05 ± 1,100.53 pg/mL, P < 0.05), whereas pleural effusion endocan levels were similar between the two groups (1.22 ± 0.74 ng/mL vs. 0.87 ± 0.53 ng/mL). The areas under the curve of VEGF and endocan were 0.73 and 0.52, respectively. Notably, the VEGF levels were similar in malignant pleural effusion, irrespective of the histological type of lung cancer. Moreover, no significant difference was found in the serum VEGF and endocan levels between patients with lung cancer and those with tuberculosis. In conclusion, high VEGF levels in pleural effusion are suggestive of malignant pleural effusion.

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

Background

The utility of tumor markers (TMs) for differentiating malignant pleural effusion (MPE) from benign pleural effusion (BPE) has been a subject of controversy. The majority of published studies are single center designed and lack validation. We performed a derivation and validation study in China to evaluate the diagnostic value of carcinoembryonic antigen (CEA) as well as carbohydrate antigen (CA) 15-3, CA 19-9 and CA 125 to differentiate between MPE and BPE.

Methods

Three hundred and twenty seven pleural effusion (PE) and paired serum samples were collected from consecutive patients with MPE or BPE in Beijing (174 patients, derivation) and Wuhan (153 patients, validation) during the same period. The concentrations of four TMs were tested using chemiluminescent microparticle immunoassay technology. The performance of the TMs was analyzed by standard receiver operating characteristic (ROC) curves.

Results

The levels of four TMs were significantly higher in MPE than in BPE and the corresponding serum. The concentrations of CEA and CA 15-3 were more stable than the concentrations of CA 125 and CA 19-9. CEA was the best single marker for discriminating MPE from BPE. With a specificity of 100% in the total population, the highest sensitivity (37.8%) using serum was found in CEA. In addition, CEA presented 19.8% sensitivity in PE and 18.0% sensitivity in the Δ(PE-serum). For CA 15-3, the sensitivity was 32.4% in PE, 15.3% in the PE/serum ratio and 25.2% in the Δ(PE-serum).

Conclusions

CEA and CA 15-3 rather than CA 125 and CA 19-9 are more reliable to differentiate between MPE and BPE. The use of the Δ(PE-serum) value in TMs, such as CEA and CA 15-3, may improve the sensitivity and specificity of the diagnosis etiology of PE.

Pleural MAC30 as a prognostic marker in NSCLC with malignant pleural effusion

Over-expressed meningioma-associate protein (MAC30) in tissues was associated with malignant tumor differentiation, metastasis and poor prognosis. However, the attention of MAC30 in pleural effusion from lung tumor is insufficient. Our retrospective study was prepared to explore the clinical values on diagnosis and prognosis of MAC30 from malignant pleural effusion (MPE) in non-small cell lung cancer (NSCLC). Levels of MAC30 were confirmed in MPE from 48 NSCLC patients and in benign pleural effusion (BPE) from 45 controls via enzyme-linked immunosorbent assay (ELISA). The association of MAC30 in MPE with clinical significance was further determined. We found that the levels of MAC30 in MPE were obviously higher than those in BPE (p < 0.05). Moreover, with a cutoff point (17.5 ng/ml), we confirmed the sensitivity and specificity of MAC30 for MPE were 82.7% and 85.3% using ROC curve analysis. Indeed, longer overall survival (OS) was present in NSCLC patients with low MAC30 expression in MPE. Multivariate analysis explicated that elevated MAC30 in MPE was an independent prognostic factor for shorter OS of NSCLC. Our data suggests that MAC30 in pleural effusion could be a potential prognostic marker in NSCLC with MPE.

Is neuron-specific enolase useful for diagnosing malignant pleural effusions? evidence from a validation study and meta-analysis

Background

Neuron-Specific enolase (NSE) has been used as a typical tumor marker and shows a potential to diagnose malignant pleural effusion (MPE). The ability of NSE in diagnosing MPE has been investigated in many studies, but with inconsistent conclusions. This study sought to investigate the diagnostic accuracy of NSE for MPE through a clinical study and together with a meta-analysis.

Methods

Pleural effusion samples from 136 patients with MPE and 102 patients with benign pleural effusion (BPE) were collected, and NSE levels were measured by electrochemiluminescence immunoassay. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of NSE to differentiate MPE from BPE. Literature search was conducted to identify suitable publications, data were extracted and diagnostic indexes including sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR) were pooled. Summary ROC curve was generated to determine the overall diagnostic accuracy of NSE for MPE.

Results

Levels of NSE were significantly increased in pleural effusion from patients with MPE than that from BPE (18.53 ± 27.30 vs. 6.41 ± 6.95 ng/ml, p < 0.001). With a cut-off value of 8.92 ng/ml, pleural NSE had a sensitivity of 59.56% and a specificity of 83.33% in diagnosing MPE. A total of 14 studies with 1896 subjects were included for meta-analysis. The diagnostic parameters of NSE were listed as follows: sensitivity, 0.53 (95% CI: 0.38–0.67); specificity, 0.85 (95% CI: 0.75–0.91); PLR, 3.54 (95% CI: 2.33–5.39); NLR, 0.56 (95% CI: 0.42–0.73); and DOR, 6.39 (95% CI: 3.72–10.96). The area under the summary ROC curve was 0.78.

Conclusions

The role of pleural NSE measurement in diagnosing MPE is limited and with a low sensitivity. The clinical utility of NSE assay should be combined with the results of other tumor markers examination and the detail clinical information of patient. Further studies are needed to confirm the role of NSE in diagnosing MPE.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3572-2) contains supplementary material, which is available to authorized users.

Diagnostic value of medical thoracoscopy in malignant pleural effusion

Background

Medical thoracoscopy has been shown to be an efficacious procedure in diagnosing unexplained exudative pleural effusions with excellent safety. This study aimed to assess the diagnostic significance of thoracoscopy in the management of patients with malignant pleural effusion (MPE).

Methods

Consecutive patients with malignant pleural effusion were retrospectively reviewed, and their demographic, radiographic, thoracoscopic and histological data were collected.

Results

Between July 2005 and June 2014, 342 of 833 patients undergoing thoracoscopy were finally confirmed to suffer from MPE. The top three frequent causes of MPE were metastatic carcinoma (79.5%), malignant mesothelioma (10.2%), and lymphoma (2.9%). Among metastatic malignancies, the most common cancer was lung cancer (85.2%), followed by breast cancer (4.4%), ovarian cancer (2.2%), pancreatic cancer (1.8%), etc. No serious adverse events associated with thoracoscopy were recorded.

Conclusions

Medical thoracoscopy is a valuable and safe tool in diagnosing malignant pleural effusion with minimal complication rates.

Reactive oxygen species modulator 1, a novel protein, combined with carcinoembryonic antigen in differentiating malignant from benign pleural effusion

The differential diagnosis of malignant pleural effusion and benign pleural effusion remains a clinical problem. Reactive oxygen species modulator 1 is a novel protein overexpressed in various human tumors. The objective of this study was to evaluate the diagnostic value of joint detection of reactive oxygen species modulator 1 and carcinoembryonic antigen in the differential diagnosis of malignant pleural effusion and benign pleural effusion. One hundred two consecutive patients with pleural effusion (including 52 malignant pleural effusion and 50 benign pleural effusion) were registered in this study. Levels of reactive oxygen species modulator 1 and carcinoembryonic antigen were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Results showed that the concentrations of reactive oxygen species modulator 1 both in pleural fluid and serum of patients with malignant pleural effusion were significantly higher than those of benign pleural effusion (both p < 0.05). The diagnostic sensitivity and specificity of pleural fluid reactive oxygen species modulator 1 were 61.54% and 82.00%, respectively, with the optimized cutoff value of 589.70 pg/mL. However, the diagnostic sensitivity and specificity of serum reactive oxygen species modulator 1 were only 41.38% and 86.21%, respectively, with the cutoff value of 27.22 ng/mL, indicating that serum reactive oxygen species modulator 1 may not be a good option in the differential diagnosis of malignant pleural effusion and benign pleural effusion. The sensitivity and specificity of pleural fluid carcinoembryonic antigen were 69.23% and 88.00%, respectively, at the cutoff value of 3.05 ng/mL, while serum carcinoembryonic antigen were 80.77% and 72.00% at the cutoff value of 2.60 ng/mL. The sensitivity could be raised to 88.17% in parallel detection of plural fluid reactive oxygen species modulator 1 and carcinoembryonic antigen concentration, and the specificity could be improved to 97.84% in serial detection.

Evaluation of two strategies for the interpretation of tumour markers in pleural effusions

Background

Pleural effusions present a diagnostic challenge. Approximately 20% are associated with cancer and some 50% require invasive procedures to perform diagnosis. Determination of tumour markers may help to identify patients with malignant effusions. Two strategies are used to obtain high specificity in the differential diagnosis of malignant pleural effusions: a) high cut-off, and b) fluid/serum (F/S) ratio and low cut-off. The aim of this study is to compare these two strategies and to establish whether the identification of possible false positives using benign biomarkers – ADA, CRP and % of polymorphonuclear cells – improves diagnostic accuracy.

Methods

We studied 402 pleural effusions, 122 of them malignant. Benign biomarkers were determined in pleural fluid, and CEA, CA72-4, CA19-9 and CA15-3 in pleural fluid and serum.

Results

Establishing a cut-off value for each TM for a specificity of 100%, a joint sensitivity of 66.5% was obtained. With the F/S strategy and low cut-off points, sensitivity was 77% and specificity 98.2%, Subclassifying cases with negative benign biomarkers, both strategies achieved a specificity of 100%; sensitivity was 69.9% for single determination and 80.6% for F/S ratio.

Conclusions

The best interpretation of TM in the differential diagnosis of malignant pleural effusions is obtained using the F/S ratio in the group with negative benign biomarkers.

Diagnostic performance of CTLA-4, carcinoembryonic antigen and CYFRA 21-1 for malignant pleural effusion

OBJECTIVES

The diagnosis of malignant pleural effusion (MPE) remains a clinical challenge. As a negative regulator of T-cell activation, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has been associated with many malignant diseases. However, there is limited data about the relationship between CTLA-4 and MPE. The present study aims to investigate whether CTLA-4 levels may correlate with presence of MPE and to assess its potential diagnostic accuracy relative to that of the established markers carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA21-1).

METHODS

Pleural effusion samples were collected from 36 patients with MPE and 48 patients with benign pleural effusion (BPE). Pleural levels of CTLA-4 were measured by ELISA; levels of CEA and CYFRA 21-1, by electrochemiluminescence immunoassay. Receiver operating characteristic curves were calculated to evaluate the ability of CTLA-4, CEA and CYFRA 21-1 to differentiate MPE from BPE.

RESULTS

Pleural levels of CTLA-4 were significantly higher in MPE than in BPE patients (471.73 ± 378.86 vs. 289.22 ± 173.67 pg/ml, p = 0.004). At a cut-off value of 351.25 pg/ml, the sensitivity and specificity of CTLA-4 in diagnosing MPE were 58.30% and 83.30%, respectively, and the area under the curve was 0.72. Pleural levels of CEA and CYFRA 21-1 were also higher in MPE. Using the combination of CTLA-4, CEA and CYFRA 21-1 increased diagnostic sensitivity to 88.89% and the area under the curve to 0.92.

CONCLUSION

The results of this preliminary study suggest that increased levels of CTLA-4 correlate with MPE, and that CTLA-4 may have some diagnostic usefulness when used in combination with conventional tumor markers such as CEA and CYFRA 21-1. These results justify larger, more rigorous studies to validate our findings.

The Exploration of Peptide Biomarkers in Malignant Pleural Effusion of Lung Cancer Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Background. Diagnoses of malignant pleural effusion (MPE) are a crucial problem in clinics. In our study, we compared the peptide profiles of MPE and tuberculosis pleural effusion (TPE) to investigate the value of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in diagnosis of MPE. Material and Methods. The 46 MPE and 32 TPE were randomly assigned to training set and validation set. Peptides were isolated by weak cation exchange magnetic beads and peaks in the m/z range of 800–10000 Da were analyzed. Comparing the peptide profile between 30 MPE and 22 TPE samples in training set by ClinProTools software, we screened the specific biomarkers and established a MALDI-TOF-MS classification of MPE. Finally, the other 16 MPE and 10 TPE were included to verify the model. We additionally determined carcinoembryonic antigen (CEA) in MPE and TPE samples using electrochemiluminescent immunoassay method. Results. Five peptide peaks (917.37 Da, 4469.39 Da, 1466.5 Da, 4585.21 Da, and 3216.87 Da) were selected to separate MPE and TPE by MALDI-TOF-MS. The sensitivity, specificity, and accuracy of the classification were 93.75%, 100%, and 96.15%, respectively, after blinded test. The sensitivity of CEA was significantly lower than MALDI-TOF-MS classification (P = 0.035). Conclusions. The results indicate MALDI-TOF-MS is a potential method for diagnosing MPE.

Utility of CEA and CA 15-3 measurements in non-purulent pleural exudates in the diagnosis of malignancy: A single-center experience

OBJECTIVE

To establish the diagnostic accuracy of pleural fluid (PF) CEA and CA 15-3 in identifying malignancy, and to determine the additional value of these markers in patients with malignant pleural effusions (MPEs) with false negative results from cytological fluid examination.

METHODS

PF concentrations of CEA and/or CA 15-3 were determined in 1,575 patients with non-purulent exudates, 549 of whom had confirmed MPEs, 284 probable MPEs, and 742 benign effusions. Tumor marker cut-off points were set to ensure 100% specificity for malignant effusion.

RESULTS

The 41, 40 and 60% of MPE patients had high PF levels of CEA (>45ng/mL), CA 15-3 (>77 UI/l) or both, respectively. These percentages were 30, 19 and 41% in MPEs with positive pleural biopsy and negative PF cytology; and 24, 13 and 35% in clinical MPEs without histocytological confirmation. Tumor markers were of no value in lymphomas and mesotheliomas. The area-under-the-curve for CEA was 0.819 (95% CI: 0,793-0,845) and for CA 15-3, it was 0.822 (95% CI: 0,796-0,847). The use of tumor markers compared to cytology alone, increased the diagnosis of malignancy by 14%.

CONCLUSIONS

Measurements of PF CEA and CA 15-3 may complement pleural cytology in the identification of MPEs.

Clinical Value of Tumor Markers for Determining Cause of Pleural Effusion

Background:

It is often challenging to distinguish tuberculous pleural effusion (TPE) from malignant pleural effusion (MPE); thoracoscopy is among the techniques with the highest diagnostic ability in this regard. However, such invasive examinations cannot be performed on the elderly, or on those in poor physical condition. The aim of this study was to explore the differential diagnostic value of carbohydrate antigen 125 (CA125), carbohydrate antigen 199 (CA199), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and squamous cell carcinoma (SCC) associated antigen in patients with TPE and MPE.

Methods:

Using electrochemiluminescence, we measured the concentration of tumor markers (TMs) in the pleural effusion and serum of patients with TPE (n = 35) and MPE (n = 95). We used receiver operating characteristic (ROC) curve analysis to evaluate the TMs and differentiate between TPE and MPE.

Results:

The cut-off values for each TM in serum were: CA125, 151.55 U/ml; CA199, 9.88 U/ml; CEA, 3.50 ng/ml; NSE, 13.27 ng/ml; and SCC, 0.85 ng/ml. Those in pleural fluid were: CA125, 644.30 U/ml; CA199, 12.08 U/ml; CEA, 3.35 ng/ml; NSE, 9.71 ng/ml; and SCC, 1.35 ng/ml. The cut-off values for the ratio of pleural fluid concentration to serum concentration (P/S ratio) of each TM were: CA125, 5.93; CA199, 0.80; CEA, 1.47; NSE, 0.76; and SCC, 0.90. The P/S ratio showed the highest specificity in the case of CEA (97.14%). ROC curve analysis revealed that, for all TMs, the area under the curve in pleural fluid (0.95) was significantly different from that in serum (0.85; P < 0.001).

Conclusions:

TMs in TPE differ significantly from those in MPE, especially when detected in pleural fluid. The combined detection of TMs can improve diagnostic sensitivity.

Overexpression of stathmin promotes metastasis and growth of malignant solid tumors: a systemic review and meta-analysis

Stathmin has been investigated to be involved in development and progress of malignant tumors. This study was to clarify the relationship between expression of stathmin and tumors and assess its clinical significance. We identified 25 studies with a total of 3,571 individuals from the electronic bibliographic databases and strictly evaluated the quality and heterogeneity of included studies. We analysed the relationship between expression of stathmin and clinical characteristics by the fixed-effects and random-effects of meta-analysis and constructed a summary receiver-operator characteristic curve to estimate the test characteristics. The results showed that patients with cancer displayed a higher stathmin expression than those of non-cancer individuals (OR, 0.31), and overexpression of stathmin correlated with tumor cell differentiation (OR, 0.73), lymph node invasion (OR, 0.80) and high TNM stage (OR, 0.67). The pooled sensitivity of stathmin for distinguishing malignant tumors was 0.73 and the specificity was 0.77. The maximum balance joint for sensitivity and specificity (the Q-value) was 0.7566 and the area under the curve (AUC) was 0.8234. In conclusion, these results showed that overexpression of stathmin intimately correlated with malignant behavior of tumors, suggesting it could be a risk factor of malignant tumors. Stathmin had great sensitivity and specificity indicated it should be a significant molecular biomarker for malignant tumors.

Advances in pleural diseases: what is the future for medical thoracoscopy?

PURPOSE OF REVIEW

Medical thoracoscopy provides the physician a window into the pleural space. The procedure allows biopsy of the parietal pleura under direct visualization with good accuracy. In addition, it achieves therapeutic goals of fluid drainage, guided chest tube placement, and pleurodesis.

RECENT FINDINGS

Comparable diagnostic yield is achieved with the flexi-rigid pleuroscope even though pleural biopsies are smaller using the flexible forceps as compared to rigid thoracoscopy. Flexi-rigid pleuroscopy is extremely well tolerated and can be performed safely as an outpatient procedure. Biopsy quality can be further enhanced with accessories that are compatible with the flex-rigid pleuroscope such as the insulated tip knife and cryoprobe.

SUMMARY

With more sensitive tools to image the pleura such as contrast-enhanced computed tomography, MRI, ultrasonography, PET, increased yield with image-guided biopsy as well as advances in cytopathology, what lies in the future for medical thoracoscopy remains to be seen. However, it is the authors' opinion that medical thoracoscopy will evolve with time, complement novel techniques, and continue to play a pivotal role in the evaluation of pleuropulmonary diseases.

A potential role for VEGF in the diagnostic approach of pleural effusions

BACKGROUND

Vascular endothelial growth factor (VEGF) may play a role in pleural fluid formation, as it represents a potent inducer of capillary permeability. We aimed to investigate the diagnostic utility of VEGF levels in pleural fluid and serum in patients with pleural effusions with initially negative diagnostic work up.

METHODS

Seventy-one patients with exudative lymphocytic pleural effusions undiagnosed after initial diagnostic work up were enrolled in this prospective study and their clinical course was followed up to 24 months. VEGF levels were measured in serum and pleural fluid by using immunoenzymometric assay.

RESULTS

During the follow up period, in 43 patients the pleural effusion was eventually attributed to malignancy while in the rest 28 patients it was due to non-malignant causes (benign and unknown origin). Patients with malignancy had significantly higher VEGF levels in pleural fluid compared to patients with non-malignant effusions (1,506 vs. 588 pg/dL, P=0.0001), while no statistically significant difference was found in the VEGF serum levels between the two groups.

CONCLUSIONS

Pleural VEGF levels may be helpful in identifying malignant pleural effusion (MPE) in patients with negative diagnostic work up at the initial assessment and help in selecting patients for more invasive procedures.

A combination of the QuantiFERON-TB Gold In-Tube assay and the detection of adenosine deaminase improves the diagnosis of tuberculous pleural effusion

The differential diagnosis of tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) remains difficult despite the availability of numerous diagnostic tools. The current study aimed to evaluate the performance of the whole blood QuantiFERON-TB Gold In-Tube (QFT-GIT) assay and conventional laboratory biomarkers in differential diagnosis of TPE and MPE in high tuberculosis prevalence areas. A total of 117 patients with pleural effusions were recruited, including 91 with TPE and 26 with MPE. All of the patients were tested with QFT-GIT, and the conventional biomarkers in both blood and pleural effusion were detected. The level of antigen-stimulated QFT-GIT in the whole blood of TPE patients was significantly higher than that of MPE (2.89 vs 0.33 IU/mL, P<0.0001). The sensitivity and specificity of QFT-GIT for the diagnosis of TPE were 93.0% and 60.0%, respectively. Among the biomarkers in blood and pleural effusion, pleural adenosine deaminase (ADA) was the most prominent biomarker, with a cutoff value of 15.35 IU/L. The sensitivity and specificity for the diagnosis of TPE were 93.4% and 96.2%, respectively. The diagnostic classification tree from the combination of these two biomarkers was 97.8% sensitive and 92.3% specific. Ultimately, the combination of whole blood QFT-GIT with pleural ADA improved both the specificity and positive predictive value to 100%. Thus, QFT-GIT is not superior to pleural ADA in the differential diagnosis of TPE and MPE. Combined whole blood QFT-GIT and pleural ADA detection can improve the diagnosis of TPE.

Clinical Investigation of Benign Asbestos Pleural Effusion

There is no detailed information about benign asbestos pleural effusion (BAPE). The aim of the study was to clarify the clinical features of BAPE. The criteria of enrolled patients were as follows: (1) history of asbestos exposure; (2) presence of pleural effusion determined by chest X-ray, CT, and thoracentesis; and (3) the absence of other causes of effusion. Clinical information was retrospectively analysed and the radiological images were reviewed. There were 110 BAPE patients between 1991 and 2012. All were males and the median age at diagnosis was 74 years. The median duration of asbestos exposure and period of latency for disease onset of BAPE were 31 and 48 years, respectively. Mean values of hyaluronic acid, adenosine deaminase, and carcinoembryonic antigen in the pleural fluid were 39,840 ng/mL, 23.9 IU/L, and 1.8 ng/mL, respectively. Pleural plaques were detected in 98 cases (89.1%). Asbestosis was present in 6 (5.5%) cases, rounded atelectasis was detected in 41 (37.3%) cases, and diffuse pleural thickening (DPT) was detected in 30 (27.3%) cases. One case developed lung cancer (LC) before and after BAPE. None of the cases developed malignant pleural mesothelioma (MPM) during the follow-up.

Diagnostic accuracy of endostatin for malignant pleural effusion: A clinical study and meta-analysis

BACKGROUND

The diagnosis of malignant pleural effusion (MPE) remains a clinical challenge. Many studies suggest that endostatin is a potential marker for MPE. This study aimed to determine the diagnostic value of endostatin with respect to MPE and to summarize the overall diagnostic performance of endostatin via a meta-analysis.

METHODS

Pleural effusion samples from patients with both malignant and nonmalignant disease were collected, and the pleural levels of endostatin and carcino-embryonic antigen (CEA) were subsequently measured. The diagnostic performances of endostatin and CEA were analyzed via standard receiver operator characteristic curve analysis methods, using the AUC as a measure of accuracy. The overall diagnostic accuracy of endostatin for MPE was summarized through a bivariate meta-analysis with standard method recommended.

RESULTS

Fifty-two patients with MPEs and 64 patients with benign pleural effusions (BPEs) were included this study. Pleural endostatin levels were significantly increased in the setting of MPE compared with BPE (104.78 ± 64.58 vs. 56.81 ± 28.84 ng/ml; p < 0.001). Using a cutoff value of 79.7 ng/ml, the sensitivity and specificity of endostatin in diagnosing MPE were shown to be 51.92% and 85.94%, respectively, and the AUC was 0.747. The combination of endostatin and CEA enhanced diagnostic performance with respect to MPE. In addition to this study, another eight studies were included in this meta-analysis. The pooled diagnostic estimates were 0.69 for sensitivity and 0.78 for specificity. The positive likelihood ratio and negative likelihood ratio for endostatin were 3.16 and 0.40, respectively. The diagnostic odds ratio was 7.89, and the AUC of the summary receiver operator characteristic curve was 0.79.

CONCLUSION

Pleural levels of endostatin are increased in the setting of MPE. However, endostatin exhibits a limited efficacy for the diagnosis of MPE and shows a relatively low sensitivity. The assessment of endostatin in combination with CEA may enhance diagnostic accuracy with respect to MPE.

Homocysteine: new tumor marker in pleural fluid

There are no published studies examining the utility of total homocysteine (HCY) in pleural fluid. The aim was to measure the accuracy of pleural fluid HCY concentration for diagnosis of malignant pleural effusion (MPE). We studied pleural fluids obtained by thoracocentesis in patients with pleural effusion. Pleural fluid HCY concentration was measured by immunonephelometry using N Latex HCY reagent with monoclonal antibody in automated analyzers BNII (Siemens Diagnostics®). Patients were classified into two groups according to the etiology of pleural effusion: benign pleural effusions (BPE) and MPE. Pleural effusion was categorized as MPE if malignant cells were demonstrated in pleural fluid or pleural biopsy. The accuracy of pleural fluid HCY concentration for diagnosis of MPE was determined using receiver operating characteristic (ROC) techniques by analyzing the area under the ROC curve (AUC). We studied 89 patients with ages between 1 and 96 years old (median = 66). Forty-eight patients were BPE and 41 were MPE. Pleural fluid HCY concentration was significantly higher in patients with MPE (median = 13.70 μmol/L) than in those with BPE (median = 8.05 μmol/L). The AUC value was 0.833 (95 % confidence interval (CI) 0.739-0.903). The optimal cutoff value was 13.1 μmol/L exhibiting 56.1 % (95 % CI 39.8-71.5) sensitivity and 85.4 % (95 % CI 72.2-93.9) specificity. Pleural fluid HCY concentration showed high diagnostic accuracy to predict whether a pleural effusion is benign or malignant. Pleural fluid HCY concentration may be measured easily and quickly in automated analyzers and could be a tumor marker commonly used for diagnosis of MPE.

[Contribution of pleural fluid analysis to the diagnosis of pleural effusion]

Analysis of pleural fluid can have, on its own, a high diagnostic value. In addition to thoracocentesis, a diagnostic hypothesis based on medical history, physical examination, blood analysis and imaging tests, the diagnostic effectiveness will significantly increase in order to establish a definite or high probable diagnosis in a substantial number of patients. Differentiating transudates from exudates by the classical Light's criteria helps knowing the pathogenic mechanism resulting in pleural effusion, and it is also useful for differential diagnosis purposes. An increased N-terminal pro-brain natriuretic peptide, both in the fluid and in blood, in a due clinical context, is highly suggestive of heart failure. The presence of an increased inflammatory marker, such as C-reactive protein, together with the presence of over 50% of neutrophils is highly suggestive of parapneumonic pleural effusion. If, in these cases, the pH is<7.20, then the likelihood of complicated pleural effusion is high. There remains to be demonstrated the usefulness of other markers to differentiate complicated from uncomplicated effusions. An adenosine deaminase > 45 U/L and>50% lymphocytes is suggestive of tuberculosis. If a malignant effusion is suspected but the cytological result is negative, increased concentrations of some markers in the pleural fluid can yield high specificity values. Increased levels of mesothelin and fibruline-3 are suggestive of mesothelioma. Immunohistochemical studies can be useful to differentiate reactive mesothelial cells, mesothelioma and metastatic adenocarcinoma. An inadequate use of the information provided by the analysis of pleural fluid would results in a high rate of undiagnosed effusions, which is unacceptable in current clinical practice.

Malignant pleural effusion: medical approaches for diagnosis and management

Malignant pleural effusions (MPEs) are the second leading cause of exudative pleural effusions after parapneumonic effusions. In the vast majority of cases, a MPE signifies incurable disease associated with high morbidity and mortality. Considerable advances have been made for the diagnosis of MPEs, through the development of improved methods in the specialized cytological and imaging studies. The cytological or histological confirmation of malignant cells is currently important in establishing a diagnosis. Furthermore, despite major advancements in cancer treatment for the past two decades, management of MPE remains palliative. This article presents a comprehensive review of the medical approaches for diagnosis and management of MPE.

Diagnostic and prognostic significance of lysophosphatidic acid in malignant pleural effusions

BACKGROUND

Lysophosphatidic acid (LPA) is an important extracellular signal transmitter and intracellular second messenger in body fluids. It can be detected in the ascitic fluid of patients with ovarian cancer. Increasing evidence shows that LPA can stimulate cancer cell proliferation and promote tumor invasion and metastasis. Our study aimed to evaluate the diagnostic value of LPA in differentiating between malignant pleural effusions (MPEs) and benign pleural effusions (BPEs) and to evaluate the association between the level of LPA in MPE and the prognosis of lung cancer patients.

PATIENTS AND METHODS

The level of LPA in the pleural effusions (PEs) of 123 patients (94 MPE, 29 BPE) with lung cancer was evaluated using an enzyme-linked immunosorbent assay. The performance of LPA was analyzed by standard Receiver operator characteristic curve (ROC) analysis methods, using the area under the curve (AUC) as a measure of accuracy. Overall survival (OS) curves and progression-free survival (PFS) curves were based on the Kaplan-Meier method, and the survival differences between subgroups were analyzed using the log-rank or Breslow test (SPSS software). A multivariate Cox proportional hazards model was used to assess whether LPA independently predicted lung cancer survival.

RESULTS

The levels of LPA differed significantly between MPE (22.08±8.72 µg/L) and BPE (14.61±5.12 µg/L) (P<0.05). Using a cutoff point of 18.93 µg/L, LPA had a sensitivity of 60% and a specificity of 83% to distinguish MPEs from BPEs with an AUC of 0.769±0.045 (SE) (P=0.000) (95% CI, 0.68-0.857). In the three pathological types of lung cancer patients with MPE, there were no significant associations between LPA levels and the length of PFS and OS (P=0.58 and 0.186, respectively). Interestingly, in the patients with MPE caused by lung adenocarcinoma there were significant associations between the LPA levels and the PFS and OS (P=0.018 and 0.026, respectively). Multivariate analysis showed that the LPA level was an independent prognostic factor for PFS in lung adenocarcinoma.

CONCLUSIONS

Our results indicate that LPA can be used as a new biomarker for the diagnosis of MPE caused by lung cancer and that higher levels of LPA are related to shorter PFS in adenocarcinoma of the lung.