How useful is thoracic tumor radiation in improving overall survival of patients with non-small-cell lung cancer and malignant pleural effusion?

This study investigated the effect of thoracic tumor radiotherapy on overall survival (OS) in patients with metastatic non-small-cell lung cancer (NSCLC) with malignant pleural effusion (MPE). The authors concluded that thoracic tumor radiotherapy effectively improved OS with acceptable toxicity levels in these patients.

NSCLC is the most common of two main types of lung cancer. MPE is often seen in the advanced stage of NSCLC. It is a fluid buildup in the space between the lungs and the chest wall (pleural space) due to the presence of cancer cells. MPE is associated with poor prognosis and decreased quality of life (QoL). Guidelines for treating NSCLC with MPE include systemic (whole-body) therapy and local MPE treatment.

Systemic therapy includes chemotherapy, targeted therapy, and immunotherapy. Tyrosine kinase inhibitors (TKIs) have played a significant role in reducing mortality levels in patients. TKIs have also been shown to improve progression-free survival (PFS). However, TKI resistance and disease progression can occur within 2 years. Several studies have found that radiotherapy can increase PFS and overall survival (OS) in patients with NSCLC without MPE. Whether radiotherapy can improve OS in patients with NSCLC with MPE remains unclear.

This study involved 148 patients with EGFR-mutant (EGFR-M) and ALK-positive (ALP-positive) NSCLC, and MPE. Patients were treated with ongoing TKIs. 72 patients received thoracic radiotherapy (group 1). 76 patients did not receive radiotherapy (group 2). Overall survival was determined for the patients. The average follow-up time was 22 months.

The average survival time for patients was 25 months in group 1 compared to 17 months in group 2. 73.2% of patients in group 1 were alive after 1 year compared to 62.5%. After 3 years, 26.7% of patients in group 1 were alive compared to 10.7% in group 2. After 5 years, 10.8% of patients in group 1 were alive compared to 2.1% in group 2. 

Most lung radiation toxicities were mild. 10.1% of patients had medium-severity radiation pneumonitis and 11.6% esophagitis in patients from group 1.

This study concluded that thoracic tumor radiotherapy may improve OS in patients with EGFR-M or ALK-P MPE-NSCLC with acceptable toxicities.

The study did not account for outpatients and was done in a single hospital setting. Evaluated treatments consisted of targeted therapy and systematic chemotherapy. Randomized, controlled trials are required to validate findings.