Pleural lavage cytology: Where do we stand?

Pleural invasion, epidermal growth factor receptor mutation and carcinoembryonic antigen level affect pleural lavage cytology-positive status in non-small-cell lung cancer

OBJECTIVES

Pleural invasion (pl) is strongly associated with the pleural lavage cytology (PLC) status. We analysed tumours with pl and evaluated the relationship between the PLC status and pl.

METHODS

We retrospectively reviewed 428 surgically treated patients who had been diagnosed with non-small-cell lung cancer with pl and had their PLC status examined between 2000 and 2016. We investigated the influence of a PLC-positive status on the prognosis and searched for the factors predictive of a PLC-positive status.

RESULTS

Seventy-eight (18%) patients were PLC positive. The recurrence-free survival of PLC-positive patients was significantly worse than that of PLC-negative patients in pl1 and pl2, but not in pl3 (5-year recurrence-free survival rate, PLC positive versus PLC negative: pl1, 22.0% vs 60.0%, P = 0.002; pl2, 30.4% vs 59.7%, P = 0.015; pl3, 50.0% vs 59.6%, P = 0.427). A multivariable analysis showed that the degree of pl (pl2-3 versus pl1) [odds ratio (OR) 5.34, P < 0.001] was an independent predictive factor for PLC positivity. Epidermal growth factor receptor (EGFR) mutation positivity (OR 5.48, P = 0.042) and carcinoembryonic antigen (CEA) ≥5 ng/ml (OR 3.78, P = 0.042) were associated with a PLC-positive status in patients with pl2-3. We found that the PLC-positive rate in patients with pl2-3 was 35.6%; however, if the tumour was EGFR mutation positive and had CEA ≥5 ng/ml, the PLC-positive rate increased to 77%.

CONCLUSIONS

If a tumour was suspected of being pl2-3 and had EGFR mutation positivity and CEA ≥5 ng/ml, the PLC-positive rate was extremely high.

CLINICAL TRIAL REGISTRATION NUMBER

Hyogo Cancer Center, G-138.

Narrative review of theoretical considerations regarding HITHOC between past and future

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Comparison of the clinical benefits for non-small cell lung cancer patients between different volume of pleural lavage fluid following video-assisted thoracoscopic lobectomy and systematic mediastinal lymph node dissection: study protocol for a randomized controlled trial

Background

Pleural lavage is regularly performed before closing the chest wall in pulmonary surgeries to prevent pleural implantation of tumor cells and postoperative infection. However, scant data could be found in the literature regarding the optimal regimen for performing pleural lavage. To establish a proper volume of pleural lavage, we herein designed a protocol for a randomized controlled trial.

Methods

A total of 400 participants with non-small cell lung cancer undergoing video-assisted thoracoscopic surgery (VATS) lobectomy and systematic mediastinal lymph node dissection (MLND) will be randomly assigned to one of two groups: group A (500 mL pleural lavage fluid) and group B (3000 mL pleural lavage fluid). The primary outcomes include the levels of leukocytes, neutrophils, and inflammatory factors on the first postoperative day. The secondary outcomes include (i) the levels of leukocytes, neutrophils, and inflammatory factors on the second and third postoperative days; (ii) the incidence of postoperative fever on the first, second, and third postoperative days; (iii) the volumes of chest drainage within the first 3 operative days, the duration of drainage, and postoperative hospitalization; and (iv) the incidence of postoperative complications (incision infection, pain, atelectasis, hemorrhage, etc.) and the incidence of pleural effusion requiring thoracic puncture or drainage within 30 days after surgery. The main content of the analysis includes effectiveness and safety analysis. We will perform subgroup analyses to identify potential influence factors.

Discussion

As far as we know, this will be the first randomized controlled trial to compare the clinical outcomes between different volumes of pleural lavage fluid following VATS and MLND. Findings from this trial will determine the appropriate amount of pleural lavage before chest wall closure.

Trial registration

This study was registered with the Chinese Clinical Trial Registry ( on 17 March 2019. ChiCTR 1900021950).

Label-free microfluidic chip for the identification of mesothelial cell clusters in pleural effusion

The detection of tumor cells and clusters in pleural effusion assists in the diagnosis of lung cancer. The proportion of tumor cells and clusters to the total number of cells in each patient varies substantially due to individual differences and the severity of the disease. The identification of one tumor cell or cluster from a large number of pleural effusions is the main challenge for hydrothorax tumor cell detection techniques. In the present study, by using A549 lung cancer and Met-5A mesothelial cell lines, a label-free microfluidic chip based on cell cluster size was designed. By setting the parameters of the chip, individual cells and clusters were able to enter different microfluidic channels. Subsequent to non-specific staining, the recovered components were stained using acridine orange (AO). A charge-coupled device camera was used to captured images of the cell, and the features of these cells were analyzed in their R and G channels using Matlab software to establish the characteristics and finally differentiate between the tumor and non-tumor cell or clusters. According to the results, when inlet A and B were under a velocity of 10 and 8.5 ml/h, respectively, the tumor cell clusters were successfully collected through microfluidic channels III–V, with a recovery rate of ~80%. Subsequent to staining with AO, the feature values in the R and G channels were identified, and initial differentiation was achieved. The present study combined the microfluidic chip, which is based on cluster size, with a computer identification method for pleural effusion. The successful differentiation of tumor cell clusters from non-tumor clusters provides the basis for the identification of tumor clusters in hydrothorax.

[Latest Progress of Intraoperative Pleural Lavage Cytology in Lung Cancer Surgery]

非小细胞肺癌（non-small cell lung cancer, NSCLC）根治术中胸腔冲洗液细胞学检查是一种常用的检测肿瘤进展并评估患者预后的诊断技术。长期以来大量研究者致力于阐明术中胸腔冲洗液细胞学检查结果与肺癌患者术后生存及肿瘤复发转移的关系。由于不同研究间存在明显异质性，其结论也各有不同。但能肯定的是，胸腔冲洗液肿瘤细胞检查阳性已被证实为手术患者的不良预后因素之一。本文尝试从临床意义、影响因素及可能发生机制等角度就近年来术中胸膜腔冲洗的研究进展作一综述。

The role of surgical intervention in lung cancer with carcinomatous pleuritis

Patients with non-small cell lung cancer (NSCLC) associated with carcinomatous pleuritis are currently classified as having stage IV disease per the 7^th edition of the tumor-node-metastasis (TNM) system, which means that the disease is deemed incurable. In fact, the 5-year survival rate of these patients was only 2% in a large global cohort collected by the International Association for the Study of Lung Cancer. However, patients with carcinomatous pleuritis have heterogeneous conditions. Some have minimal pleural effusion, which is first detected at thoracotomy; some have numerous pleural nodules without any effusion; and others have massive effusion and nodules with symptoms. Several investigators have reported the contribution of surgical intervention to favorable outcomes of patients with carcinomatous pleuritis first detected at thoracotomy. These reports show a relatively higher 5-year survival rate of 15% to 37%. The extrapleural pneumonectomy (EPP) is a radical surgical procedure that is commonly employed in the treatment of malignant pleural mesothelioma. Two authors reported that they have successfully performed EPPs for the treatment of patients with carcinomatous pleuritis. Their 5-year survival rates were estimated to be 22% and 61%, a significantly improved outcome. Although the development of chemotherapeutic agents, including molecular targeted drugs, might have the potential to prolong the survival of patients with advanced lung cancer, surgical interventions including EPP might have a role in improving the survival of patients with carcinomatous pleuritis of minimal disease and those without massive effusion or numerous pleural nodules.

The IASLC Lung Cancer Staging Project: Proposals for the Revision of the M Descriptors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer

INTRODUCTION

The aim of this study is to analyze all metastatic (M) categories of the current tumor, node, and metastasis (TNM) classification of lung cancer with the objective of providing suggestions for modifications of the M component in the next edition of the TNM classification for lung cancer.

METHODS

The new International Association for the Study of Lung Cancer lung cancer database was created from 94,708 patients diagnosed as having lung cancer between 1999 and 2010. Including further patients submitted through the electronic data capture system to Cancer Research and Biostatistics until 2012, all together 1059 non-small-cell lung cancer cases were available for a detailed analysis of the clinical M categories. Overall survival was calculated using the Kaplan-Meier method, and prognosis was assessed using a Cox proportional hazards regression analysis.

RESULTS

No significant differences were found among the M1a (metastases within the chest cavity) descriptors. However, when M1b (distant metastases outside the chest cavity) were assessed according to the number of metastases, tumors with a single metastasis in a single organ had significantly better prognosis than those with multiple metastases in one or several organs.

CONCLUSIONS

In this revision of the TNM classification, cases with pleural/pericardial effusions, contralateral/bilateral lung nodules, contralateral/bilateral pleural nodules, or a combination of multiple of these parameters should continue to be grouped as M1a category. Single metastatic lesions in a single distant organ should be newly designated to the M1b category. Multiple lesions in a single organ or multiple lesions in multiple organs should be reclassified as M1c category. This new division can serve as a first step into providing rational definitions for an oligometastatic disease stage in non-small-cell lung cancer in the future.

Trends in Pleural Effusion Research

Background:

Research in pleural diseases has traditionally been neglected but is now growing.

Objectives:

This study aimed to analyze scientific research trends on pleural effusions over the last decades.

Method:

We conducted a bibliometric analysis of the Scopus database from its inception to March 2016, searching for original articles and reviews on “pleural effusion” (key word). Journal, year of publication, number of citations, authors and their affiliations, and the Hirsch (H)-index for some of these variables were recorded and analyzed.

Results:

A total of 15 982 documents were retrieved, of which half have been published in the last 18 years and a quarter during the last 8 years. Chest ranked first regarding the number of documents on pleural effusions (both absolute number and yearly rate) and their scientific relevance (H-index of 76). The United States had contributed the most to pleural research productivity (23%). American pulmonologists Dr Richard Light and Dr Steven Sahn exhibited the highest number of papers (206 and 156, respectively) and author H-indexes (44 and 38, respectively).

Conclusion:

There is growing research activity in the field of pleural effusions, which has gained relevance and visibility in clinical respiratory journals. The United States is the leader in quantity and quality of research productivity in pleural medicine.

The diagnosis of pleural effusions

Pleural effusions arise from a variety of systemic, inflammatory, infectious and malignant conditions. Their precise etiological diagnosis depends on a combination of medical history, physical examination, imaging tests and pertinent pleural fluid analyses; including specific biomarkers (e.g., natriuretic peptides for heart failure, adenosine deaminase for tuberculosis, or mesothelin for mesothelioma). Invasive procedures, such as pleuroscopic biopsies, may be required for persistently symptomatic effusions which remain undiagnosed after the analysis of one or more pleural fluid samples. However, whenever parietal pleural nodularity or thickening exist, image-guided biopsies should first be attempted. This review addresses the current diagnostic approach to pleural effusions secondary to heart failure, pneumonia, cancer, tuberculosis and other less frequent conditions.

Pleural involvement in lung cancer

The pleural space, a sterile secluded environment in the thoracic cavity, represents an attractive metastatic site for various cancers of lung, breast and gastrointestinal origins. Whereas lung and breast adenocarcinomas could invade the pleural space because of their anatomic proximity, "distant" cancers like ovarian or gastrointestinal tract adenocarcinomas may employ more active mechanisms to the same end. A pleural metastasis is often accompanied by a malignant pleural effusion (MPE), an unfavorable complication that severely restricts the quality of life and expectancy of the cancer patient. MPE is the net "product" of three different processes, namely inflammation, enhanced angiogenesis and vascular leakage. Current efforts are focusing on the identification of cancer cell autocrine (specific mutation spectra and biochemical pathways) and paracrine (cytokine and chemokine signals) characteristics as well as host features (immunological or other) that underlie the MPE phenotype. Herein we examine the pleural histology, cytology and molecular characteristics that make the pleural cavity an attractive metastasis destination for lung adenocarcinoma. Mesothelial and tumor features that may account for the tumor's ability to invade the pleural space are highlighted. Finally, possible therapeutic interventions specifically targeting MPE are discussed.

Clinical features and survival of lung cancer patients with pleural effusions

BACKGROUND AND OBJECTIVE

The clinical relevance of pleural effusions in lung cancer has seldom been approached systematically. The aim of this study was to determine the prevalence, causes and natural history of lung cancer-associated pleural effusions, as well as their influence on survival.

METHODS

Retrospective review of clinical records and imaging of 556 consecutive patients with a newly diagnosed lung cancer over a 4-year period at our institution.

RESULTS

Lung cancer comprised 490 non-small cell and 66 small cell types. About 40% of patients with lung cancer developed pleural effusions at some time during the course of their disease. In half the patients, the effusions were too small to be tapped. These effusions did not progress to require a pleural intervention. Patients with minimal effusions had a worse prognosis compared to patients without pleural effusions (median survival of 7.49 vs 12.65 months, P < 0.001). Less than 20% of the 113 patients subjected to a diagnostic thoracentesis had benign causes for their effusions. Palliative pleural procedures (like therapeutic thoracenteses, pleurodesis or tunnelled pleural catheters) were conducted in 79 (84%) of the 94 malignant effusions. An effusion's size equal to or greater than half of the hemithorax was a strong predictor of the need for a palliative procedure. Overall survival of patients with malignant effusions was 5.49 months.

CONCLUSIONS

Malignant pleural effusions are a poor prognostic factor in the setting of lung cancer, which includes minimal effusions not amenable to tapping.

Lung cancer coexisting with ipsilateral pleural effusion

SUMMARY 

Invasion beyond the elastic layer of the visceral pleura and/or diffuse pleural metastatic spread affects negatively survival in lung cancer. Presence of pleural effusion is also associated with poor prognosis, and image techniques can be of great help for diagnosis. When pleural fluid cytology is negative, thoracoscopy is advisable before attempting tumor resection, in order to detect unsuspected pleural metastases. If widespread pleural malignancy is confirmed, chemical pleurodesis using graded talc (with particles larger than 20 µm in diameter) is the best option, unless the lung is unable to re-expand. In this case, or when a previous pleurodesis has failed, or there is a short life expectancy, placement of a indwelling pleural catheter is the treatment of choice.

Endocardial Invasion of Lung Cancer Undiagnosable before Autopsy

A 59-year-old male patient presented with left chest discomfort on admission. His medical history included encephalitis in childhood and his smoking history was 20 cigarettes per day for 40 years. A physical examination showed an anemic and edematous face with weak respiratory sounds in the left lung. The patient had elevated calcium levels and decreased hemoglobin and potassium. His parathyroid hormone-related protein level was elevated. Thoracic radiography showed cardiomegaly and computed tomography revealed a left lung mass with invasion of the heart and pleural effusion. Magnetic resonance imaging showed endocardial invasion of the tumor mass. Gallium-68 imaging revealed positive accumulation in the region surrounding the heart. No diagnoses were possible upon frequent cytology of his sputum and pleural effusion. The patient died from congestive heart failure with anoxia 38 days after admission. An autopsy revealed tumoral mass occlusion in the left main bronchus and tumoral invasion of the left atrium, left ventricle, and aorta.