From the Guidelines
Pleural effusion in lung cancer patients occurs when cancer cells spread to the pleural space, causing fluid accumulation between the lung and chest wall, and the most recent and highest quality evidence suggests that this condition is a common complication of advanced cancer, affecting up to 15% of all patients with cancer 1. This happens through several mechanisms:
- cancer can directly invade the pleura,
- block lymphatic drainage that normally removes pleural fluid,
- or release inflammatory substances that increase fluid production and pleural permeability. Additionally, cancer cells can obstruct blood vessels, leading to increased hydrostatic pressure and fluid leakage. The effusion often contains malignant cells and can cause symptoms like shortness of breath, chest pain, and cough. The presence of pleural effusion typically indicates advanced disease and may significantly impact a patient's quality of life and respiratory function.
Treatment approaches include:
- thoracentesis to remove fluid,
- pleurodesis to prevent reaccumulation,
- indwelling pleural catheters for recurrent effusions,
- and addressing the underlying cancer with chemotherapy, immunotherapy, or targeted therapy to reduce the production of pleural fluid, as recommended by recent guidelines 1. The focus of treatment is inevitably palliative, and aimed at relieving symptoms, with a median survival after the diagnosis of malignant pleural effusion ranging from 3 months to 12 months depending on underlying patient and tumour factors 1. It is essential to evaluate the patient’s symptoms, general health and functional status, and expected survival when considering palliative therapy, and to investigate other causes of dyspnea if it is not relieved by thoracentesis 1.
The management of malignant pleural effusions should be individualized, taking into account the patient's performance status, the primary tumour and its response to systemic therapy, and lung re-expansion following pleural fluid evacuation 1. Systemic treatment should be started if no contraindications exist, and it may be combined with therapeutic thoracentesis or pleurodesis, especially in patients with tumors likely to respond to chemotherapy, such as small-cell lung cancer 1. Overall, the management of malignant pleural effusions requires a comprehensive approach, considering both the treatment of the underlying cancer and the relief of symptoms, to improve the patient's quality of life and respiratory function.
From the Research
Causes of Pleural Effusion in Lung Cancer Patients
- Pleural effusions in lung cancer patients are often caused by metastases to the pleura, which is a common site for cancer spread 2, 3.
- The presence of a pleural effusion in lung cancer patients indicates advanced disease and poor survival, with the cancer often being upstaged to stage 4 2, 3.
- Minimal pleural effusions, which are not amenable to diagnostic thoracentesis, are also associated with a poorer overall survival in lung cancer patients 3.
Diagnosis and Treatment of Pleural Effusion
- Diagnosis of malignant pleural effusion involves thoracic imaging, such as computed tomography or thoracic ultrasound, and cytology examination of pleural fluid or tissue 2, 4.
- Treatment of pleural effusion in lung cancer patients focuses on palliation and relief of symptoms, with options ranging from drainage with thoracentesis or indwelling pleural catheter to more definitive options like pleurodesis 2, 4, 5.
- The choice of treatment depends on various factors, including the patient's overall health, life expectancy, and the presence of other symptoms or complications 2, 4, 5.
Prognosis and Survival
- The presence of a pleural effusion in lung cancer patients is associated with a poor prognosis and reduced survival, with median survival ranging from 5.5 to 7.5 months 3, 6.
- Certain factors, such as visceral pleural invasion, positive pleural lavage cytology, and unexpected pleural involvement during surgery, are predictors of adverse survival in lung cancer patients with pleural effusion 3.