Background: In epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC), brain metastasis is known as a poor prognosis factor. However, prognostic factors in the patients without brain metastasis remain unclear. In this study, we aimed to clarify the differences between metastatic site and prognosis in common EGFR-mutant NSCLC patients without brain metastasis.
Methods: Chemotherapy-naïve, advanced EGFR-mutant NSCLC patients without brain metastasis diagnosed between January 2010 and March 2016 were enrolled. We evaluated prognosis according to the presence or absence of bone metastases, liver metastasis, and pleural effusion.
Results: A total of 50 EGFR-mutant NSCLC patients without brain metastasis were enrolled. The median progression-free survival and overall survival were significantly shorter in patients with pleural effusion than in those patients without (progression-free survival 7.0 months, 95% confidence interval [CI] 3.7-13.0 vs. 13.0 months, 95% CI 9.1-21.7, hazard ratio [HR] 2.29, 95% CI 1.11-4.73, P = 0.020; overall survival 19.5 months, 95% CI 5.7-28.8 vs. 55.3 months, 95% CI 24.0-not evaluable, HR 3.00, 95% CI 1.35-6.68, P = 0.005). Pleural effusion was an independent factor of poor prognosis for progression-free survival (HR 3.44, 95% CI 1.50-7.88, P = 0.003) and overall survival (HR 2.34, 95% CI 1.00-5.44, P = 0.049).
Conclusion: Pleural effusion might be a poor prognosis factor for advanced EGFR-mutant NSCLC patients without brain metastasis treated with first-generation EGFR-tyrosine kinase inhibitors. Further precision medicine according to the metastatic site is required.
Keywords: Epidermal growth factor receptor; metastasis; non-small cell lung cancer; pleural effusion; prognosis factor.
© 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.