Association Of The Prognostic Nutrition Index With Overall Survival Time Of The Patients With Brain Metastases Of Lung Adenocarcinoma

Objective:To explore the effect of prognostic nutrition index(PNI)on the overall survival time of patients with brain metastases of lung adenocarcinoma.Methods:A retrospective analysis was performed on the clinic data of 274 patients who were admitted to Shanxi Tumor Hospital and confirmed with brain metastases of lung adenocarcinoma from May 2013 to May 2016.The prognosic factors for brain metastases such as PNI,gender,age,smoking history,EGFR mutation status,karnofsky performance status(KPS)score,the numbers of brain lesions,treatments of brain lesions,extracranial metastases and the status of primary disease were analyzed.The PNI was calculated as serum albumin number(g/L)+5×total lymphocyte count(×10~9/L).The receiver operating characteristic(ROC)curve was drawn and the patients were divided into high PNI group and low PNI group by the optimal cut-off value of PNI.The univariate and multivariate prognostic analyses were performed by the Log-rank test and the COX proportional hazards model.Results:The median survival time was 11.2 months in all patients with brain metastases,the median survival time of the low PNI group(PNI?50.45)and high PNI group(PNI>50.45)were 10.13 months and 15.17 months respectively;the univariate analysis showed that gender(9.67 vs.13.90,P=0.019),age(11.70 vs.9.20,P=0.046),smoking(12.50 vs.9.20,P=0.009),EGFR mutation status(9.20 vs.16.23,P<0.001),KPS score(3.10vs.12.50 vs.23.80,P<0.001),extracrnial metastases(12.53 vs.10.20, P=0.036),treatments on the brain lesions(6.37 vs.15.10 vs.17.80 vs.10.50 vs.9.67,P<0.001)and PNI(10.13 vs.15.17,P=0.005)were prognostic predictors.The multivariate analysis showed that age(HR=1.580,95%CI=1.104~2.295,P=0.012),EGFR mutation status(HR=0.549,95%CI=0.408~0.738,P<0.001),KPS scores of brain metastasis(HR=0.077,95%CI=0.045~0.134,P<0.001),treatments on brain metastases(HR=0.882,95%CI,0.789~0.987,P=0.029)and PNI(HR=0.614, 95%CI=0.437~0.861,P=0.005)were prognostic predictors.Moreover,in patients with the GPA=1.5~2.0 score,higher PNI may have a better prognosis(11.70 vs.16.07,P=0.022).Conclusion:The prognostic nutritional index(PNI)is an independent prognostic predictor of brain metastases in patients with lung adenocarcinoma,which has certain clinical practical value.The high prognosis nutritional index is correlated to the long survival time of patients with brain metastases of lung adenocarcinoma.It is also expected to be an independent prognostic factor in DS-GPA.