Small cell lung cancer is known to spread (metastasize) to the brain. Two years after diagnosis, 50% of patients will develop brain metastases if no preventive treatment is given. Once brain metastases develop, response to treatment is poor. It has previously been shown that patients with limited stage small cell lung cancer have longer disease-free and overall survivals with the addition of prophylactic cranial irradiation (PCI), meaning radiation to the whole brain to prevent metastases). This study looked at similar treatment in patients with extensive stage small cell lung cancer.
Patients with extensive stage (ES) disease who had significant reduction in their tumors following chemotherapy were treated with PCI given over 5-12 days. 286 patients participated in the study and were randomized to receive PCI or observation only.
Brain metastases developed in 14.6% of the patients treated with PCI, compared with 40.4% in the observation group. As expected, PCI had no effect on tumors elsewhere in the body. PCI did improve progression-free survival (PFS). PFS is the time until the disease begins to grow and progress. One-year survival was also improved in the PCI group, 27.1% versus 13.3%. Toxicity during treatment was mild and included headache, nausea/vomiting, fatigue and skin reactions. Late effects (those occurring months to years after therapy) were seen in 35% of patients and included headache.
The results of this trial should change the standard of care in this disease, as patients with ES-SCLC who respond to systemic therapy should routinely receive PCI.
Partially funded by an unrestricted educational grant from Bristol-Myers Squibb.