Diagnostic benefits of the combined use of liquid-based cytology, cell block, and carcinoembryonic antigen immunocytochemistry in malignant pleural effusion

Comparison of Claudin-4, BerEP4, Carcinoembryonic Antigen and MOC31 in Serous Fluids Metastases Demonstrate High Sensitivity of Claudin-4 at Low Cellularity

INTRODUCTION

Claudin-4 has been described as a highly sensitive immunocytochemical marker for detection of metastatic carcinoma cells in effusion cytology specimens. This study aims to challenge the performance of claudin-4 in different types of malignancies and low cellularity specimens, by comparison with other markers in a large cohort of carcinomatous effusion specimens.

METHODOLOGY

Cell block preparations from peritoneal and pleural fluid specimens were retrieved, with malignant (carcinoma) diagnoses confirmed by review of hospital diagnosis code and pathology reports. Claudin-4, BerEP4, CEA, and MOC31 immunocytochemistry were performed and scored by expression proportion and intensity. Tumor cellularity was assessed for subgroup analysis of low cellularity specimens.

RESULTS

Totally 147 specimens (70 pleural, 77 peritoneal) of 68 lung, 62 breast, 9 gynecological, and 7 gastrointestinal carcinomas were retrieved. The average proportion expression of claudin-4 was highest (89.6%, vs. CEA 40.5%, BerEp4 18.6%, MOC31 16.8%) and the percentage of strong expression was highest for claudin-4 (72.1%). Expression levels of claudin-4 were consistently higher than other markers in subgroups of all primary sites. The difference was more significant for low cellularity specimens. High (≥50%) proportion expression was seen for 96.61% of cases for claudin-4 (vs. BerEp4 8.77%, CEA 46.55%, MOC31 8.77%, p < 0.001). These factors contributed to a low concordance between claudin-4 and BerEp4, CEA and MOC31 (K = 0.010-0.043).

CONCLUSION

Claudin-4 is more sensitive than CEA, BerEp4 and MOC31, suitable for low cellularity specimens of most types of metastatic carcinoma and is a robust immunocytochemical marker for carcinoma that can be used solitarily.

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Fractal Dimension, Circularity, and Solidity of Cell Clusters in Liquid-Based Endometrial Cytology Are Potentially Useful for Endometrial Cancer Detection and Prognosis Prediction

Endometrial cancer (EC) in women is increasing globally, necessitating improved diagnostic methods and prognosis prediction. While endometrial histology is the conventional approach, liquid-based endometrial cytology may benefit from novel analytical techniques for cell clusters. A clinical study was conducted at the University of Fukui Hospital from 2012 to 2018, involving 210 patients with endometrial cytology. The liquid-based cytology images were analyzed using cell cluster analysis with Image J software. Logistic regression, ROC analysis, and survival analysis were employed to assess the diagnostic accuracy and prognosis between cell cluster analysis and EC/atypical endometrial hyperplasia (AEH). Circularity and fractal dimension demonstrated significant associations with EC and AEH, regardless of age and cytology results. The ROC analysis revealed improved diagnostic accuracy when combining fractal dimension with cytology, particularly in menopausal age groups. Lower circularity and solidity were independently associated with poor overall survival, while higher fractal dimension values correlated with poorer overall survival in Grades 2 and 3 endometrial cancers. The combination of circularity and fractal dimension with cytology improved diagnostic accuracy for both EC and AEH. Moreover, circularity, solidity, and fractal dimension may serve as prognostic indicators for endometrial cancer, contributing to the development of more refined screening and diagnostic strategies.

Principles of Analytic Validation of Immunohistochemical Assays: Guideline Update

CONTEXT.—

In 2014, the College of American Pathologists developed an evidence-based guideline to address analytic validation of immunohistochemical assays. Fourteen recommendations were offered. Per the National Academy of Medicine standards for developing trustworthy guidelines, guidelines should be updated when new evidence suggests modifications.

OBJECTIVE.—

To assess evidence published since the release of the original guideline and develop updated evidence-based recommendations.

DESIGN.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and update the original guideline recommendations using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS.—

Two strong recommendations, 1 conditional recommendation, and 12 good practice statements are offered in this updated guideline. They address analytic validation or verification of predictive and nonpredictive assays, and recommended revalidation procedures following changes in assay conditions.

CONCLUSIONS.—

While many of the original guideline statements remain similar, new recommendations address analytic validation of assays with distinct scoring systems, such as programmed death receptor-1 and analytic verification of US Food and Drug Administration approved/cleared assays; more specific guidance is offered for validating immunohistochemistry performed on cytology specimens.

An Integrated Clinical and Computerized Tomography-Based Radiomic Feature Model to Separate Benign from Malignant Pleural Effusion

INTRODUCTION

Distinguishing between malignant pleural effusion (MPE) and benign pleural effusion (BPE) poses a challenge in clinical practice. We aimed to construct and validate a combined model integrating radiomic features and clinical factors using computerized tomography (CT) images to differentiate between MPE and BPE.

METHODS

A retrospective inclusion of 315 patients with pleural effusion (PE) was conducted in this study (training cohort: n = 220; test cohort: n = 95). Radiomic features were extracted from CT images, and the dimensionality reduction and selection processes were carried out to obtain the optimal radiomic features. Logistic regression (LR), support vector machine (SVM), and random forest were employed to construct radiomic models. LR analyses were utilized to identify independent clinical risk factors to develop a clinical model. The combined model was created by integrating the optimal radiomic features with the independent clinical predictive factors. The discriminative ability of each model was assessed by receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA).

RESULTS

Out of the total 1,834 radiomic features extracted, 15 optimal radiomic features explicitly related to MPE were picked to develop the radiomic model. Among the radiomic models, the SVM model demonstrated the highest predictive performance [area under the curve (AUC), training cohort: 0.876, test cohort: 0.774]. Six clinically independent predictive factors, including age, effusion laterality, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 125 (CA125), and neuron-specific enolase (NSE), were selected for constructing the clinical model. The combined model (AUC: 0.932, 0.870) exhibited superior discriminative performance in the training and test cohorts compared to the clinical model (AUC: 0.850, 0.820) and the radiomic model (AUC: 0.876, 0.774). The calibration curves and DCA further confirmed the practicality of the combined model.

CONCLUSION

This study presented the development and validation of a combined model for distinguishing MPE and BPE. The combined model was a powerful tool for assisting in the clinical diagnosis of PE patients.

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.

A single tertiary institution review of the international system for serous fluid cytopathology and the impact of cell block and ancillary studies on its performance

INTRODUCTION

We sought to assess the utility of the International System for Serous Fluid Cytopathology (TIS) in the context of our department's routine practice.

MATERIALS AND METHODS

We examined 1028 archived effusion cytology (pleural, peritoneal, and pericardial) cases from 2018 to 2019, and re-classified them along the international system into the following diagnostic categories: nondiagnostic (ND), negative for malignancy (NFM), atypia cells of undetermined significance (AUS), suspicious for malignancy (SFM), and malignant (MAL).

RESULTS

The full distribution of the cases examined was as follows: ND 2.0%; NFM 66.1%; AUS 6.0%; SFM 4.7%; MAL 21.2%. Overall risk of malignancy for each category was calculated as: ND 30.0%; NFM 18.0%; AUS 61.9%; SFM 100%; MAL 94.4%. The overall performance attributes of TIS were as follows: sensitivity 57.1%; specificity 98.3%; positive predictive value 94.4%; negative predictive value 82.0%; diagnostic accuracy 84.5%.

CONCLUSIONS

The new classification was simple and intuitive to use and our results appear to fall within the expected ranges of the new guidelines, with risk of malignancy and accuracy comparable to similar studies. The availability of a cell block allowed for refinement of the diagnosis in a majority of cases with equivocal cytology, though this was dependent on the cell yield.

Diagnostic sensitivity of pleural fluid cytology in malignant pleural effusions: systematic review and meta-analysis

BACKGROUND

Pleural fluid cytology is an important diagnostic test used for the investigation of pleural effusions. There is considerable variability in the reported sensitivity for the diagnosis of malignant pleural effusions (MPE) in the literature.

OBJECTIVE

The purpose of this review is to determine the diagnostic sensitivity of pleural fluid cytology for MPE, both overall and by tumour type, to better inform the decision-making process when investigating pleural effusions.

DATA SOURCES

A literature search of EMBASE and MEDLINE was performed by four reviewers. Articles satisfying inclusion criteria were evaluated for bias using the QUADAS-2 tool.

DATA EXTRACTION

For quantitative analysis, we performed a metaanalysis using a binary random-effects model to determine pooled sensitivity. Subgroup analysis was performed based on primary cancer site and meta-regression by year of publication.

SYNTHESIS

Thirty-six studies with 6057 patients with MPE were included in the meta-analysis. The overall diagnostic sensitivity of pleural fluid cytology for MPE was 58.2% (95% CI 52.5% to 63.9%; range 20.5%-86.0%). There was substantial heterogeneity present among studies (I² 95.5%). For primary thoracic malignancies, sensitivity was highest in lung adenocarcinoma (83.6%; 95% CI 77.7% to 89.6%) and lowest in lung squamous cell carcinoma (24.2%; 95% CI 17.0% to 31.5%) and mesothelioma (28.9%; 95% CI 16.2% to 41.5%). For malignancies with extrathoracic origin, sensitivity was high for ovarian cancer (85.2%; 95% CI 74.2% to 96.1%) and modest for breast cancer (65.3%; 95% CI 49.8% to 80.8%).

CONCLUSIONS

Pleural fluid cytology has an overall sensitivity of 58.2% for the diagnosis of MPE. Clinicians should be aware of the high variability in diagnostic sensitivity by primary tumour type as well as the potential reasons for false-negative cytology results.PROSPERO registration numberCRD42021231473.

Malignant pleural disease: a pragmatic guide to diagnosis

PURPOSE OF REVIEW

The diagnosis of malignant pleural disease is important in the care of patients with cancer. However, a one-size-fits-all approach to diagnosis may lead to delays in care as the sensitivity of each biopsy modality varies and can be dependent on the tumor type. We review current literature on pleural biopsy techniques and propose a diagnostic algorithm for suspected malignant pleural disease.

RECENT FINDINGS

Recent literature has shown that the sensitivity of pleural fluid cytology varies based on tumor type resulting in a limited value of repeated thoracenteses in many cases. Furthermore, the ability to test for molecular biomarkers on pleural fluid samples has contributed to the recommendations to send large volumes of pleural fluid for analysis. Studies have also supported the consideration of medical thoracoscopy earlier in the diagnostic work-up of malignant pleural disease.

SUMMARY

The decision to repeat a diagnostic thoracentesis when suspecting malignant pleural effusions should take into account the primary tumor type. Open pleural biopsy with medical thoracoscopy has been shown to be a relatively safe diagnostic modality with high sensitivity and should be considered in patients with a nondiagnostic thoracentesis.

Cellular composition research of serous pleural effusion fluids. Conceptual issues of preanalytics

The purpose of this work was to show the effectiveness of the cytological method on a small number of observations, excluding all possible errors of the preanalytical stage. The paper presents several simple and easily reproducible algorithms for the cytological study of serous pleural effusions with small cellular content. On the example of 20 observations of the study of the cellular composition of serous exudates, a direct dependence of the research results on the preanalytical stage is shown. A complete study of effusion fluids in compliance with all stages of preanalytics and the use of modern methods of cytological diagnostics makes it possible to nullify the options for false-negative.

Detection of carcinoma in serous effusions: a review

A malignant serous effusion is one of the most common complications of advanced tumors, indicating a poor prognosis and having a profound impact on diagnosis, treatment, and prognosis. It is of great significance to identify benign and malignant effusions quickly and accurately. Both cellular and non-cellular components in the effusion can be employed for detection, diagnostic methods are necessary to obtain a definite diagnosis and more relevant information such as tumor classification. In this review, we focus on the comparison of several widespread cytological preparation methods, enrichment technology of exfoliated cells, and present tests for serous effusions, mainly including routine and special stains, immunocytochemistry, electron microscopy, enzyme-linked immunosorbent assay, flow cytometry, and molecular analysis.

Clinical Evaluation of Li Brush Endometrial Samplers for Diagnosing Endometrial Lesions in Women With Intrauterine Devices

Background: For women with intrauterine devices (IUDs), it is difficult to sample the endometrium when abnormal uterine bleeding occurs or when regular screening of endometrial cancer is proposed. The purpose of this study is to evaluate the validity of endometrial sampling using Li Brush in IUD users.

Methods: This study was a prospective cohort study and conducted in two parts. Part I was to assess the impact of Li Brush on the position of IUDs. Transvaginal ultrasound was used to locate IUDs before and after sampling. Part II was to explore the diagnostic accuracy of Li Brush in detecting endometrial lesions. IUD users with irregular uterine bleeding were recruited in the IUD group and IUD non-users who arranged for dilatation and curettage (D&C) were recruited in the control group. The endometrium was sampled by Li Brush for cells and by D&C for tissues in both groups. The satisfactoriness of sampling and validity of Li Brush were evaluated.

Results: Seventeen cases in part I confirmed no significant difference in the position of IUDs before and after sampling (p = 0.20). 112 IUD users and 139 IUD non-users were recruited in part II. Li Brush achieved 94.64 and 92.09% satisfactory sampling rates in the IUD group and control group, respectively, without statistically significant difference between the two groups (p = 0.42). The Sensitivity and specificity of Li Brush for detection of endometrial lesions in IUD group were 95.35 and 87.76% respectively.

Conclusions: Li Brush used for endometrial biopsy did not affect the position of IUDs and had high yield of satisfactory samples and good validity for endometrial diagnoses. It was feasible to screen endometrial lesions by Li Brush for women with IUDs.

Development and validation of a novel scoring system developed from a nomogram to identify malignant pleural effusion

BACKGROUND

This study aimed to establish and validate a novel scoring system based on a nomogram for the differential diagnosis of malignant pleural effusion (MPE) and benign pleural effusion (BPE).

METHODS

Patients with PE and confirmed aetiology who underwent diagnostic thoracentesis were included in this study. One retrospective set (N = 1261) was used to develop and internally validate the predictive model. The clinical, radiological and laboratory features were collected and subjected to logistic regression analyses. The primary predictive model was displayed as a nomogram and then modified into a novel scoring system, which was externally validated in an independent set (N = 172).

FINDINGS

The novel scoring system was composed of fever (3 points), erythrocyte sedimentation rate (4 points), effusion adenosine deaminase (7 points), serum carcinoembryonic antigen (CEA) (4 points), effusion CEA (10 points) and effusion/serum CEA (8 points). With a cutoff value of 15 points, the area under the curve, specificity and sensitivity for identifying MPE were 0.913, 89.10%, and 82.63%, respectively, in the training set, 0.922, 93.48%, 81.51%, respectively, in the internal validation set and 0.912, 87.61%, 81.36%, respectively, in the external validation set. Moreover, this scoring system was exclusively applied to distinguish lung cancer with PE from tuberculous pleurisy and showed a favourable diagnostic performance in the training and validation sets.

INTERPRETATION

This novel scoring system was developed from a retrospective study and externally validated in an independent set based on six easily accessible clinical variables, and it exhibited good diagnostic performance for identifying MPE.

FUNDING

NFSC grants (no. 81572942, no. 81800094).

Ber-EP4 staining in effusion cytology: A potential source of false positives

The distinction between reactive mesothelium and carcinoma in serous effusions can be very difficult. Immunocytochemistry (ICC) is the most widely used tool to improve the diagnostic accuracy of body fluid cytology, with several ICC markers being proposed. Ber-EP4 antibody has shown high sensitivity and specificity rates for diagnosing metastatic carcinoma. In our department, we have detected Ber-EP4 positivity in mesothelium in some cytological specimens. We reviewed all articles on Ber-EP4 staining in effusion cytology, summarized current findings and analyzed the staining pattern of all cases expressing Ber-EP4. Some cases showing Ber-EP4 positivity in mesothelium have been reported, most of which showed only weak Ber-EP4 staining or staining of less than 50% of mesothelial cells. However, some cases may show strong positivity both in cytological and histological specimens. Clinicians and pathologists should be aware of this source of misdiagnosis, and ICC results in mesothelium should be always interpreted cautiously and correlated with clinical tests, other ICC markers and patient's previous history.

Multiplexed molecular profiling of lung cancer with malignant pleural effusion using next generation sequencing in Chinese patients

Lung cancer is the most common type of cancer and the leading cause of cancer-associated death worldwide. Malignant pleural effusion (MPE), which is observed in ~50% of advanced non-small cell lung cancer (NSCLC) cases, and most frequently in lung adenocarcinoma, is a common complication of stage III-IV NSCLC, and it can be used to predict a poor prognosis. In the present study, multiple oncogene mutations were detected, including 17 genes closely associated with initiation of advanced lung cancer, in 108 MPE samples using next generation sequencing (NGS). The NGS data of the present study had broader coverage, deeper sequencing depth and higher capture efficiency compared with NGS findings of previous studies on MPE. In the present study, using NGS, it was demonstrated that 93 patients (86%) harbored EGFR mutations and 62 patients possessed mutations in EGFR exons 18-21, which are targets of available treatment agents. EGFR L858R and exon 19 indel mutations were the most frequently observed alterations, with frequencies of 31 and 25%, respectively. In 1 patient, an EGFR amplification was identified and 6 patients possessed a T790M mutation. ALK + EML4 gene fusions were identified in 6 patients, a ROS1 + CD74 gene fusion was detected in 1 patient and 10 patients possessed a BIM (also known as BCL2L11) 2,903-bp intron deletion. In 4 patients, significant KRAS mutations (G12D, G12S, G13C and A146T) were observed, which are associated with resistance to afatinib, icotinib, erlotinib and gefitinib. There were 83 patients with ERBB2 mutations, but only two of these mutations were targets of available treatments. The results of the present study indicate that MPE is a reliable specimen for NGS based detection of somatic mutations.

Diagnostic Value of the EZH2 Immunomarker in Malignant Effusion Cytology

BACKGROUND

Differentiating reactive mesothelial cells from metastatic carcinoma in effusion cytology is a challenging task. The application of at least 4 monoclonal antibodies including 2 epithelial markers (Ber-EP4, MOC-31, CEA, or B72.3) and 2 mesothelial markers (calretinin, WT-1, CK5/6, or HBME-1) are often useful in this distinction; however, it is not readily available in many resource-limited developing countries. Aberrant immunoexpression of enhancer of zeste homolog 2 (EZH2), a transcriptional repressor involved in cancer progression, is observed widely in various malignancy. In this study, we evaluate the diagnostic value of EZH2 as a single reliable immunomarker for malignancy in effusion samples.

METHODS

A total of 108 pleural, peritoneal, and pericardial effusions/washings diagnosed as unequivocally reactive (n = 41) and metastatic carcinoma (n = 67) by cytomorphology over 18 months were reviewed. Among the metastatic carcinoma cases, 54 were adenocarcinoma and others were squamous cell carcinoma (n = 1), carcinosarcoma (n = 1), and carcinoma of undefined histological subtypes (n = 11). Cell block sections were immunostained by EZH2 (Cell Marque, USA). The percentages of EZH2-immunolabeled cells over the total cells of interest were calculated. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off score to define EZH2 immunopositivity.

RESULTS

A threshold of 8% EZH2-immunolabeled cells allows distinction between malignant and reactive mesothelial cells, with 95.5% sensitivity, 100% specificity, 100% positive predictive value, and 93.2% negative predictive value (p < 0.0001). The area under the curve was 0.988.

CONCLUSION

EZH2 is a promising diagnostic biomarker for malignancy in effusion cytology which is inexpensive yet trustworthy and could potentially be used routinely in countries under considerable economic constraints.

Are we ready to develop a tiered scheme for the effusion cytology? A comprehensive review and analysis of the literature

BACKGROUND

Cytology is widely utilized in the initial evaluation of fluid accumulation in the body cavities. The aim of this study was to determine the accuracy of cytology in distinguishing between benign and malignant (MAL) effusions.

METHODS

A comprehensive and systematic review of the literature was conducted to evaluate the accuracy of serous effusion cytology (SEC) against tissue biopsy/resection histology, imaging, or clinical follow-up as the reference test. Risk of publication bias and level of heterogeneity in the included studies was assessed. Meta-regression was performed to assess the effect of various variables on the accuracy of SEC.

RESULTS

Eighty studies met the inclusion criteria for meta-analysis comprising of 34 941 samples; of which 52 (0.2%), 22 202 (72.7%), 194 (0.6%), 711 (2.3%), and 6507 (21.3%) could be reclassified as nondiagnostic (ND), negative for malignancy (NFM), atypical (atypia of uncertain significance-AUS), suspicious for malignancy (SFM), and malignant (MAL), respectively. On follow-up, the mean risk of malignancy for ND, NFM, AUS, SFM, MAL was 17.4%, 20.7%, 65.9%, 81.8%, and 98.9%, respectively. A total of 73 studies were included in estimating the diagnostic accuracy of SEC. The bivariate mixed-effect model estimated the SEC sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio as 73.1%, 99.9%, 7850.6%, 2112.2%, and 0.27%, respectively.

CONCLUSION

Serous effusion cytology shows high specificity and moderate sensitivity in the evaluation of serous effusions. A tiered classification scheme can improve the consistency of terminology for reporting SEC results, thus improving communication between the pathologists and clinical team, and quality of patient care.

[Detection of carcinoembryonic antigen levels in pleural effusion and serum and their ratio for differential diagnosis of pleural effusion resulting from tuberculosis and lung cancer]

OBJECTIVE

To study the clinical value of detecting carcinoembryonic antigen levels in pleural effusion (PCEA) and serum (SCEA) and their ratio (P/S) in the differential diagnosis of pleural effusions resulting from tuberculosis and lung cancer.

METHODS

This retrospectively study was conducted among 82 patients with pleural effusion caused by pulmonary tuberculous (TB; control group) and 120 patients with pleural effusion resulting from lung cancer in our hospital between April, 2016 and March, 2018. PCEA, SCEA and P/S were compared between the two groups and among the subgroups of lung cancer patients with squamous cell carcinoma (SqCa), adenocarcinoma (ACA), small cell carcinoma (SCLC). The receiveroperating characteristic curve (ROC) analysis was used to confirm the optimal critical value to evaluate the diagnostic efficiency of different combinations of PCEA, SCEA and P/S.

RESULTS

PCEA, SCEA and P/S were significantly higher in the overall cancer patients and in all the 3 subgroups of cancer patients than in the patients with TB (P < 0.05). The areas under the ROC curve of PCEA, SCEA and P/S were 0.925, 0.866 and 0.796, respectively; PCEA had the highest diagnostic value, whose diagnostic sensitivity, specificity, accurate rate, and diagnostic threshold were 83.33%, 96.34, 88.61%, and 3.26 ng/ml, respectively; SCEA had the lowest diagnostic performance; the diagnostic performance of P/S was between that of SCEA and PCEA, but its combination with SCEA greatly improved the diagnostic performance and reduced the rates of misdiagnosis and missed diagnosis. Parallel tests showed that the 3 indexes combined had significantly higher diagnostic sensitivity than each or any two of the single indexes (P < 0.05), but the diagnostic specificity did not differ significantly. The area under the ROC curve of combined detections of the 3 indexes was 0.941 for diagnosis of lung cancer-related pleural effusion, higher than those of any other combinations of the indexes.

CONCLUSIONS

The combined detection of PCEA, SCEA and P/S has a high sensitivity for diagnosis of lung cancer-related pleural effusion and provides important information for rapid and accurate diagnosis of suspected cases.