External validation of the graded prognostic assessment for patients with non-small cell lung cancer and brain metastases using molecular markers (Lung-molGPA)

Purpose: Patients with non-small cell lung cancer (NSCLC) and brain metastases (BM) represent a markedly heterogeneous population.The diagnosis-specific graded prognostic assessment is one of the prognostic indexes, which includes patient age, performance status, extracranial disease, and number of BM.As an updated prognostic model (lung molecular graded prognostic assessment Lung-molGPA) with the incorporation of the molecular factor (epidermal growth factor receptor EGFR and anaplastic lymphoma kinase ALK alterations) was introduced, this study aims to validate the Lung-molGPA model in Korean patient population.Materials and Methods: Four hundred thirty-three patients (368 adenocarcinoma and 65 nonadenocarcinoma) with NSCLC with newly diagnosed BM between 2005 and 2017 were reviewed retrospectively and scored using the Lung-molGPA model. Results:The overall median survival for the cohort in the present study was 14 months (16.5 months in the adenocarcinoma and 8.0 months in the nonadenocarcinoma, respectively; p = 0.003).For patients with adenocarcinoma, the median survival for patients with a Lung-molGPA score of 3.5 to 4.0 was 44.7 months, while the median survival was only 8.9 months in patients scoring 0-1.0, 17.0 months in patients scoring 1.5-2.0,and 30.2 months for scores of 2.5-3.0 (p < 0.001).For patients with nonadenocarcinoma, the median survival for scores 0-1.0, 1.5-2.0,and 2.5-3.0 were 6.7, 10.3, and 13.2 months, respectively (p = 0.041).Conclusion: Notable prognostic factors for patients with NSCLC and BM include the patient's age, performance status, metastatic lesions, and the molecular status of the adenocarcinoma.Our independent validation in a single-institution Korean patient cohort confirmed the applicability of Lung-molGPA as a prognostic tool.