Prognosis Of Patients With Brain Metastases From Non-small Cell Lung Cancer Treated With Different Radiotherapy Modalities

Objective: To analyze the prognosis and influencing factors of different radiotherapy modalities in patients with brain metastases from non-small cell lung cancer(NSCLC),and to find the best beneficiaries of different radiotherapy modalities,so as to provide reference for individualized treatment of patients with brain metastases.Methods: Between January 2013 and December 2015,a total of 634 patients with brain metastasis from non-small lung cancer in the fourth hospital of Hebei Medical University were enrolled.The clinical characteristics of these 634 patients,combined with follow-up data were analyzed.According to different radiotherapy modalities,they were divided into three groups: no WBRT in 330 cases,WBRT alone in 127 cases,WBRT combined with a radiotherapy boost(WBRT+Boost)in 177 patients.The endpoints included intracranial progression free survival(PFS)and overall survival(OS).The prognosis of different radiotherapy modalities was further analyzed,according to the number of brain metastases,GPA score,KPS score and whether they received targeted therapy or not.Results: The median PFS and OS of all patients were 6.9 months and 9.0months respectively.On univariate analysis,the 1-year PFS rates of the three groups were 15.1%,16.3% and 40.2%,and the 2-year PFS rates were 0.0%,3.1% and 4.2% respectively(P=0.002).The 1-year OS rates of the three groups were 33.7%,38.2% and 48.1%,and the 2-year OS rates were 13.2%,19.0%,and 25.3%,respectively(P<0.001).Multivariate analysis showed that different radiotherapy modalities were independent factors of PFS and OS.The independent beneficial factors of intracranial PFS included female,less number of brain cancer metastasis,brain metastasis surgery,targeted therapy and chemotherapy.Independent beneficial factors of OS included female,KPS≥ 90,the number of brain cancer metastasis < 5,no extracranial metastases,targeted therapy and chemotherapy.Subgroup analysis: among the subgroups with different GPA score,KPS score,number of brain cancer metastases and targeted therapy,the 1-year and 2-year OS and PFS of WBRT+boost were better than that of WBRT alone.Among the subgroups with GPA score of 2.5-4,there were significant differences in 1-year and2-year OS and PFS of WBRT+boost and WBRT alone(P= 0.021,P=0.034).There were significant differences in 1-year and 2-year OS and PFS between the two groups for patients with 1 brain metastasis(P=0.046,P=0.034).As for patients with 2-3 brain metastases,only the difference of 1-year and 2-year PFS between the two groups was statistically significant(P=0.022).For patients who didn’t receive targeted therapy,there were significant differences in 1-year and 2-year OS and PFS between the two groups(P=0.014,P=0.021).Conclusions:1.WBRT can improve OS and PFS of NSCLC patients with brain metastasis,and with a radiotherapy boost can further improve the prognosis.2.Compared with WBRT alone,WBRT + boost may improve intracranial PFS and OS in patients with GPA score of 2.5-4,1 brain metastasis and no targeted therapy,but WBRT + boost only benefits PFS in patients with brain metastases of 2-3.