PUB062 Risk Factors of Brain Metastasis during the Course of EGFR-TKIs Therapy for Patients with EGFR-Mutated Advanced Lung Adenocarcinoma

Abstract

Brain metastasis (BM) remains a therapeutically challenging issue, which often predicts poor prognosis. Moreover, there are still some patients developing BM during the course of EGFR-TKIs therapy, although EGFR-TKIs are effective for EGFR-mutated NSCLC patients with BM. Therefore, controversial value of prophylactic cranial irradiation (PCI) in NSCLC in terms of survival benefit prompted us to explore the possible risk factors for BM during the course of EGFR-TKIs therapy from EGFR-mutated advanced lung adenocarcinoma and identify the potential population most likely to benefit from PCI. We retrospectively reviewed the records of 134 patients with EGFR-TKIs therapy from EGFR-mutated advanced lung adenocarcinoma between 2008 and 2012. Among them, 78 patients (58.2 %) were confirmed to have EGFR exon 19 point mutations, while 56 patients (41.8%) had EGFR exon 21 point mutations. The cumulative incidence of BM was calculated by the Kaplan–Meier method and differences between the groups were analyzed using the log-rank test. Multivariate Cox regression analysis was used to assess the independent risk factors of BM. Thirty-four patients (34/134, 25.4%) developed BM during the course of EGFR-TKIs therapy. Multivariate analysis indicated that age ≤ 53 years (HR: 2.751, 95% CI: 1.326-5.707; p = 0.007), serum carcinoembryonic antigen (CEA) ≥ 23 ng/mL (HR: 3.197, 95% CI: 1.512-6.758; p = 0.002) and EGFR exon 21 point mutations (HR: 2.769, 95 % CI: 1.355-5.659; p= 0.005) were the independent high-risk factors for developing BM, which could offer important insights into the individualized treatment. Patients, with age ≤ 53 years, CEA ≥ 23 ng/mL and exon 21 point mutations from EGFR-mutated advanced lung adenocarcinoma, are at the highest risk for developing BM during the course of EGFR-TKIs therapy, and are most likely to benefit from PCI. Additionally, further studies are warranted to validate our findings.