Update on managing malignant pleural effusions

Management of malignant pleural effusions has evolved over the last decade. Insertion of tunneled pleural catheters is now a first-line management strategy, along with pleurodesis. An interactive panel discussion, Management of Malignant Pleural Effusions: All You Need to Know, on Tuesday at 11:15 am CT will explore each management strategy, new combination techniques for management, and factors dictating the choice of one technique over the other in this patient population.

About half of patients with lung cancer eventually develop pleural effusions. Several well-designed, practice-changing trials have been published recently and are reflected in the latest management guidelines for malignant pleural effusions from the American Thoracic Society and the European Respiratory Society.

“The traditional approach has been to aspirate fluid, send for cytology, and repeat if the result is negative,” said session chair Sujith Cherian, MD, FCCP, Associate Professor of Pulmonary and Critical Care Medicine and Director of Quality at the Lyndon Baines Johnson Hospital, University of Texas Health-McGovern Medical School. “This approach should not be uniform. Several factors, including type of suspected malignancy and patient preference, should be considered to approach diagnosis. In the age of targeted and personalized therapy, cellular material acquired through thoracentesis is seldom sufficient to perform the necessary molecular diagnostics, highlighting the need for alternate diagnostic pathways.”

Variability in diagnostic yield

When it comes to diagnosis, Dr. Cherian said, all pleural effusions are not created equal.

The familiar approach of thoracentesis, aspiration, and cytology might be appropriate for adenocarcinoma of the lung or carcinoma of the breast or ovary because the positive yield is typically high for these types of cancer.

Other malignancies, including mesothelioma, sarcomas, and hematologic malignancies, typically show diagnostic yield between 6% and 40%. Certain types of mesotheliomas are not exfoliative and not amenable to diagnosis through cytologic evaluation.

The term malignant pleural effusion implies the presence of cancer cells within the pleural fluid or cancer involvement of pleural cavity. Several other mechanisms may result in para-malignant pleural effusions, including tumor obstruction, trapped lung physiology, lymphatic blockage resulting in chylothorax, medication, and radiation effects. This differentiation is very important due to poor prognostic implications associated with malignant pleural effusions.

“We want to highlight the use of medical thoracoscopy, a rigid, semi-rigid or, more recently, the rigid mini-thoracoscope, as a diagnostic tool that should be used perhaps more aggressively or earlier as a one-stop diagnostic and therapeutic procedure in malignant pleural effusions,” Dr. Cherian said. “We can get biopsies with close to 95% sensitivity to exclude malignancy.”

Evolving strategies in management

New data have also changed approaches to managing malignant pleural effusions. Despite new advances in cancer treatment, management options remain palliative and aim to improve quality of life. While chemical pleurodesis was once considered the first approach in malignant pleural effusions, current guidelines recommend indwelling pleural catheters as alternative first-line therapeutic interventions. A daily drainage approach has been shown to result in quicker spontaneous pleurodesis. Indwelling pleural catheters can be safely placed as outpatient and are associated with lower in-hospital stay, but they have a higher adverse effect profile compared with chemical pleurodesis alone.

Talc has been the sclerosing agent of choice for chemical pleurodesis. Thoracoscopic poudrage and talc slurry through chest tubes have overall equivalence for pleurodesis. Recent trials have highlighted combined therapies using indwelling pleural catheters and chemical pleurodesis with talc. If medical thoracoscopy is performed, a combined approach using talc poudrage and indwelling pleural catheters also shows excellent success rates.

“A more aggressive approach can reduce the time to diagnosis with important therapeutic implications for the patient,” Dr. Cherian said. “Ultimately, it is paramount that a multidisciplinary discussion involving the interventional pulmonologist, medical oncologist, and primary care physician be promoted to help decide the best option for the patient.”