Radiation-refractory brain metastases in patients with non-small cell lung cancer

Background: Numerous studies have focused on the treatment of non-small cell lung cancer patients with brain metastases. However, to our knowledge, few have sought to examine outcomes in patients who required whole brain radiation and developed radiation-refractory disease. Methods: This study examined the medical records of all non-small cell lung cancer patients who developed brain metastases between 2004 and 2013, required whole brain radiation, and received their cancer treatment at the Mayo Clinic in Rochester, Minnesota. Results: A total of 141 patients, most of whom were symptomatic, met the above criteria. Of these, 33 (23%) did not tolerate a corticosteroid taper and were therefore deemed to have radiation-refractory disease. The median survival of patients with and without radiation-refractory disease was 3.12 and 4.27 months, respectively, (hazard ratio [HR]: 0.65 [95% confidence interval (CI): 0.44-0.99]; p=0.04 by log rank test). In a subgroup analysis of patients with radiation-refractory disease (n=33) and radio-responsive disease (n=43), median survival was 3.12 and 5.94 months, respectively (HR: 0.43 [95% CI: 0.26-0.70]). Among patients with radiation-refractory disease, 12 received chemotherapy after radiation, and two received erlotinib. Systemic therapy was associated with improved symptoms in two patients but did not appear to improve survival. Conclusion: Non-small cell lung cancer patients with radiation-refractory brain metastases represent a small subgroup who have a short survival and who appear to derive minimal benefit from systemic cancer therapy.