Critical analysis of the utility of initial pleural aspiration in the diagnosis and management of suspected malignant pleural effusion

Diagnostic value and safety of medical thoracoscopy in undiagnosed pleural effusions-a prospective observational cohort study

Background

With the need for "actionable histology" in the current era of targeted cancer treatment, and the increasing practice of upfront thoracoscopy (without a prior diagnostic thoracentesis) or a "biopsy first" approach in suspected malignant pleural effusions (MPEs), we sought to prospectively evaluate the diagnostic accuracy, including full molecular profiling of cancer, and safety of medical thoracoscopy (MT) at a tertiary referral hospital.

Methods

Patients with MT performed for an undiagnosed pleural effusion between January 2020 and December 2022 were included in this observational cohort study. All procedures were performed with a semirigid thoracoscope under conscious sedation. Clinical outcomes and adverse events were recorded prospectively.

Results

We evaluated 141 patients, with a mean age of 67±12 years. Talc poudrage was performed in 67 (47.5%) patients with a median of 2 [interquartile range (IQR), 1-4] hospitalisation days after MT. Upfront thoracoscopy was performed in approximately half (55.3%) of patients. The overall diagnostic accuracy of MT was 95.7% in our cohort. A final diagnosis of cancer was made in 116 (82.3%) patients, with lung (67.2%) and breast cancer (8.6%) the most common. The diagnostic sensitivity of MT for malignancy was 94.8%, and molecular profiling of relevant cancer types for oncogenic mutations was achieved in all patients with malignancy seen on histopathology. The most common non-malignant diagnosis was tuberculous pleuritis in 14 patients (9.9%). Major complications occurred in 3 (2.1%) patients. Two patients had re-expansion pulmonary edema that resolved with low flow oxygen supplementation in the general ward, and one patient required intensive care unit admission for cardiac tamponade from a malignant pericardial effusion. There were no cases of mortality, bleeding complications or persistent air leaks.

Conclusions

MT is a well-tolerated and effective option for the evaluation of undiagnosed pleural effusions. With expanding utility and expertise with MT and other pleural interventions, the challenge for respiratory physicians is integrating these into expeditious diagnostic and effective therapeutic pathways, individualised to patients' needs.

Malignant pleural effusion: current understanding and therapeutic approach

Malignant pleural effusion (MPE) is a common complication of thoracic and extrathoracic malignancies and is associated with high mortality and elevated costs to healthcare systems. Over the last decades the understanding of pathophysiology mechanisms, diagnostic techniques and optimal treatment intervention in MPE have been greatly advanced by recent high-quality research, leading to an ever less invasive diagnostic approach and more personalized management. Despite a number of management options, including talc pleurodesis, indwelling pleural catheters and combinations of the two, treatment for MPE remains symptom directed and centered around drainage strategy. In the next future, because of a better understanding of underlying tumor biology together with more sensitive molecular diagnostic techniques, it is likely that combined diagnostic and therapeutic procedures allowing near total outpatient management of MPE will become popular. This article provides a review of the current advances, new discoveries and future directions in the pathophysiology, diagnosis and management of MPE.

Optimal diagnostic strategies for pleural diseases and identifying high-risk patients

INTRODUCTION

Pleural diseases encompass a broad range of conditions with diverse and heterogenous etiologies. Diagnostics in pleural diseases thus represents a challenging field with a wide array of available testing to distinguish between the numerous causes of pleural disease. Nonetheless, deploying best practice diagnostics in this area is essential in reducing both duration o the investigation pathway and symptom burden.

AREAS COVERED

This article critically appraises the optimal diagnostic strategies and pathway in patients with pleural disease, reviewing the latest evidence and key practice points in achieving a treatable diagnosis in patients with pleural disease. We also cover future and novel directions that are likely to influence pleural diagnostics in the near future. PubMed was searched for articles related to pleural diagnostics (search terms below), with the date ranges including June 2012 to June 2022.

EXPERT OPINION

No single test will ever be sufficient to provide a diagnosis in pleural conditions. The key to reducing procedure burden and duration to diagnosis lies in personalizing the investigation pathway to patients and deploying tests with the highest diagnostic yield early (such as pleural biopsy in infection and malignancy). Novel biomarkers may also allow earlier diagnostic precision in the near future.

Achieving Molecular Profiling in Pleural Biopsies: A Multicenter, Retrospective Cohort Study

BACKGROUND

Pleural biopsy findings offer greater diagnostic sensitivity in malignant pleural effusions compared with pleural fluid. The adequacy of pleural biopsy techniques in achieving molecular marker status has not been studied, and such information (termed "actionable" histology) is critical in providing a rational, efficient, and evidence-based approach to diagnostic investigation.

RESEARCH QUESTION

What is the adequacy of various pleural biopsy techniques at providing adequate molecular diagnostic information to guide treatment in malignant pleural effusions?

STUDY DESIGN AND METHODS

This study analyzed anonymized data on 183 patients from four sites across three countries in whom pleural biopsy results had confirmed a malignant diagnosis and molecular profiling was relevant for the diagnosed cancer type. The primary outcome measure was adequacy of pleural biopsy for achieving molecular marker status. Secondary outcomes included clinical factors predictive of achieving a molecular diagnosis.

RESULTS

The median age of patients was 71 years (interquartile range, 63-78 years), with 92 of 183 (50%) male. Of the 183 procedures, 105 (57%) were local anesthetic thoracoscopies (LAT), 12 (7%) were CT scan guided, and 66 (36%) were ultrasound guided. Successful molecular marker analysis was associated with mode of biopsy, with LAT having the highst yield and ultrasound-guided biopsy the lowest (LAT vs CT scan guided vs ultrasound guided: LAT yield, 95%; CT scan guided, 86%; and ultrasound guided, 77% [P = .004]). Biopsy technique and size of biopsy sample were independently associated with successful molecular marker analysis. LAT had an adjusted OR for successful diagnosis of 30.16 (95% CI, 3.15-288.56; P = .003) and biopsy sample size an OR of 1.18 (95% CI, 1.02-1.37) per millimeter increase in tissue sample size (P < .03).

INTERPRETATION

Although previous studies have shown comparable overall diagnostic yields, in the modern era of targeted therapies, this study found that LAT offers far superior results to image-guided techniques at achieving molecular profiling and remains the optimal diagnostic tool.

Malignant pleural effusion: Updates in diagnosis, management and current challenges

Malignant pleural effusion (MPE) is a common condition which often causes significant symptoms to patients and costs to healthcare systems. Over the past decade, the management of MPE has progressed enormously with large scale, randomised trials answering key questions regarding optimal diagnostic strategies and effective management strategies. Despite a number of management options, including talc pleurodesis, indwelling pleural catheters and combinations of the two, treatment for MPE remains symptom directed and centered around drainage strategy. The future goals for providing improved care for patients lies in changing the treatment paradigm from a generic pathway to personalised care, based on probability of malignancy type and survival. This article reviews the current evidence base, new discoveries and future directions in the diagnosis and management of MPE.

Diagnostics in Pleural Disease

Pleural disease diagnostics represent a sprawling topic that has enjoyed a renaissance in recent years from humble beginnings. Whilst pleural patients are heterogeneous as a population and in the aetiology of the disease with which they present, we provide an overview of the typical diagnostic approach. Pleural fluid analysis is the cornerstone of the diagnostic pathway; however, it has many shortcomings. Strong cases have been made for more invasive upfront investigations, including image-guided biopsies or local anaesthetic thoracoscopy, in selected populations. Imaging can guide the diagnostic process as well as act as a vehicle to facilitate therapies, and this is never truer than with the recent advances in thoracic ultrasound.