A study on different therapies and prognosis-related factors for brain metastases in lung adenocarcinoma patients with driver mutation

Brain metastases (BMs) are frequently occurred in lung adenocarcinoma with driver mutation. There is a need to explore multi-discipline treatments and prognostic factors in those patients with most frequent driver mutations: EGFR mutation and ALK fusion. In the retrospective study, different therapies and prognostic factors were compared between EGFR and ALK-driven lung adenocarcinoma with BMs. 516 patients with EGFR mutation and 76 with ALK fusion were screened for this study, 303 (58.7%) and 34 (44.7%) had BM respectively. In multivariate analyses, the pretreatment factors including delayed BMs and asymptomatic BMs, treatment strategies including the first-generation tyrosine kinase inhibitor (TKI) and cranial radiotherapy (RT) treatment, were associated with much better OS in EGFR mutation patients. Moreover, we found EGFR-mutation patients receiving erlotinib would achieve better survival than those receiving gefitinib (P = 0.032). However, BM patients with ALK fusion treated by only the first generation TKI (HR = 0.23, P = 0.036) or cranial RT (HR = 0.12, P = 0.003), had better OS. After balancing of baseline characteristics of the two groups, there was no significant difference in the survival between BM patients with EGFR mutation and ALK fusion. And only cranial RT was associated with better survival in those patients (HR = 0.52, P < 0.001). In the BM patients of lung adenocarcinoma with driver mutation, TKI underlie the therapy strategies, but cranial RT still plays an important role while receiving the first generation TKI.