Management of malignant pleural effusions

Malignant pleural effusion is a common problem in respiratory medicine and oncology and in some series accounts for up to 50% of all pleural effusions.1 2 The median survival following diagnosis ranges from three to 12 months and is largely dependent upon the underlying malignancy. Currently, lung cancer is the most common metastatic tumour to the pleura in men and breast cancer in women. Both malignancies account for 50–65% of all malignant effusions while lymphomas, genitourinary, and gastrointestinal tumours account for a further 25%, and 7–15% of all malignant effusions have no identifiable primary.3-5

Malignant effusions result predominantly from obstruction and disruption of lymphatic channels by malignant cells. However, vascular endothelial growth factor (VEGF), a potent angiogenic mediator and promoter of endothelial permeability, is produced in significant amounts by diseased pleural tissue and is thought to play a part in the formation of malignant effusions and local tumour growth.6 7

The general approach to managing malignant effusions is determined by symptoms (dyspnoea, exercise tolerance limitation, and chest discomfort), performance status of the patient, expected survival, and response of the known primary tumour to systemic treatment. Intervention options range from observation in the case of asymptomatic effusions through simple thoracentesis to more invasive methods such as thoracoscopy, pleuroperitoneal shunting, and pleurectomy. Repeated aspiration is favoured in patients with limited survival and poor performance status and obviates lengthy hospitalisation. In the patient with reasonable survival expectancy and good performance status, every attempt should be made to prevent recurrence of the effusion. Intercostal tube drainage with instillation of a sclerosing agent, resulting in the obliteration of the pleural space, is the most widely used and cost effective method to control recurrent symptomatic malignant effusions.