Mutation status and postresection survival of patients with non–small cell lung cancer brain metastasis: implications of biomarker-driven therapy

Abstract

OBJECTIVE Non–small cell lung cancer (NSCLC) is the most common primary tumor to develop brain metastasis. Prognostic markers are needed to better determine survival after neurosurgical resection of intracranial disease. Given the importance of mutation subtyping in determining systemic therapy and overall prognosis of NSCLC, the authors examined the prognostic value of mutation status for postresection survival of patients with NSCLC brain metastasis. METHODS The authors retrospectively analyzed all cases of NSCLC brain metastasis with available molecular testing data that were resected by a single surgeon at a single academic center from January 2009 to February 2019. Mutation status, demographic characteristics, clinical factors, and treatments were analyzed. Association between predictive variables and overall survival after neurosurgery was determined with Cox regression. RESULTS Of the included patients (n = 84), 40% were male, 76% were smokers, the mean ± SD Karnofsky Performance Status was 85 ± 14, and the mean ± SD age at surgery was 63 ± 11 years. In total, 23%, 26%, and 4% of patients had EGFR, KRAS, and ALK/ROS1 alterations, respectively. On multivariate analysis, survival of patients with EGFR (HR 0.495, p = 0.0672) and KRAS (HR 1.380, p = 0.3617) mutations were not significantly different from survival of patients with wild-type (WT) tumor. However, the subgroup of patients with EGFR mutation who also received tyrosine kinase inhibitor (TKI) therapy had significantly prolonged survival (HR 0.421, p = 0.0471). In addition, postoperative stereotactic radiosurgery (HR 0.409, p = 0.0177) and resected tumor diameter < 3 cm (HR 0.431, p = 0.0146) were also significantly associated with prolonged survival, but Graded Prognostic Assessment score ≤ 1.0 (HR 2.269, p = 0.0364) was significantly associated with shortened survival. CONCLUSIONS Patients with EGFR mutation who receive TKI therapy may have better survival after resection of brain metastasis than patients with WT tumor. These results may inform counseling and decision-making regarding the appropriateness of resection of NSCLC brain metastasis.