The efficacy and clinical survival outcome of different first-line treatments in EGFR-mutant non-small cell lung cancer with brain metastases.

Abstract

2028 Background: Brain metastasis is one of the most important factors for poor prognosis of lung cancer, and the incidence of brain metastasis in EGFR-mutant(m+) advanced NSCLC is more common. The first-generation EGFR TKI is a standard first-line treatment. The purpose of this study is to explore the best method for EGFRm+ NSCLC with brain lesions, and to find out correlative factors influencing survival outcome. Methods: The clinical data of NSCLC with brain metastases was retrospectively analyzed. All patients had received 1st generation EGFR TKI, and patients were divided into 4 group, group A : EGFR TKI monotherapy, group B: EGFR TKI plus chemotheapy(CT),Group C:EGFR TKI plus bevacizumab, group D :EGFR TKI plus CT plus bevacizumab.The efficacy of intracranial and extracranial lesions and survival outcome were analyzed. Results: A total of 584 EGFRm+ advanced NSCLC patients from December 2017 to May 2020 were screened,and 228(39%) had brain metastasis at baseline in the treatment-naive. Among them, 194pts had complete medical record and follow-up data. At the follow-up date (January 1, 2021), 147pts had disease progressed and 78pts had died. Intracranial PFS of group A,B,C,D were 11.1m(n = 97), 11.3m(n = 59)，21.2m(n = 19), and 18.9m(n = 19), respectively. No difference was found between A and B group (P = 0.745), so as C and D group (P = 0.684).But, the intracranial PFS of group C+D(with bevacizumab) was significantly longer than group A+B(11.3m (95%CI 12.2-14.8) vs 21.0m (95%CI 15.2-22.7), P = 0.007).The extracranial PFS of groups A, B, C, and D were 11.0m, 14.3m, 21.7m, and 18.9m, respectively,and the P value were 0.006, 0.002, and 0.011, respectively when compared with group A. The mOS of groups A,B were 27.8m and 24.2m,respectively, but group C and D had not yet reached. The intracranial ORR of group A, B, C, and D were 17.9% (14/78), 37.3% (19/51), 60.0% (9/15), and 66.7% (10/15), respectively. The extracranial ORR were 48.5% (47/97), 81.1% (43/53), 73.7% (14/19), and 73.7% (14/19),respectively. Conclusions: For EGFR-mutant NSCLC with brain metastases, the first-generation EGFR-TKI plus bevacizumab can significantly improve the efficacy of intracranial lesions, delay the progression of intracranial lesions, and prolong suvival time, Although the first-generation EGFR-TKI plus CT could improve extracranial ORR when compared with ERGF-TKI monotherapy, it has limited efficacy on intracranial lesions and could not increase survival time.