ADA And Cystatin C As Prognostic Factors In Patients With Castration-resistant Prostate Cancer

Objective: To explore the prognostic significance of the expression level of adenosine deaminase(ADA)and Cystatin C(Cys C)before chemotherapy in patients with castration-resistant prostate cancer(CRPC).Methods:The medical records of 76 patients with CRPC were reviewed.These patients were diagnosed and underwent docetaxel-based chemotherapy combined with endocrine therapy in Xinjiang military Command General Hospital between January 2008 and January 2016.Statistical analysis was performed to compare with clinical pathological factors.Univariable survival analysis and COX regression were performed to predict the clinical and prognostic value of the pre-chemotherapy ADA and Cys C.Results:(1)There were 76 CRPC patients,including high ADA group 37 cases(ADA>18U/L)and low ADA group 39 cases(ADA?18U/L).The expression of ADA before chemotherapy was significantly correlated with TNM stages and distant metastasis(P <0.05),but no association was observed with the age,Gleason score,baseline PSA,number of chemotherapy cycles and PSA response(P>0.05).(2)The median PFS of the patients with CRPC was 14 months and the median OS was in the range of 20 months.The median PFS of high ADA group and low ADA group were 17 and 12 months,and the difference was statistically significant(P=0.006).The median overall survival time were 26 and 18 months,and the difference was statistically significant(P< 0.001).(3)Univariate analysis showed that TNM stage,Gleason score,distant metastasis,PSA response and the expression of ADA before chemotherapy were significant factors influencing the survival of patients with CRPC(P<0.05).But the age,baseline PSA and the number of chemotherapy cycles were confounding factors,the differences were not statistically significant.COX multivariate analysis showed that the tumor nodes metastasis stage at diagnosis(P=0.003)and the expression of ADA before chemotherapy(P=0.007)were independent risk factors of progression free survival of patients with CRPC.The distant metastasis(P=0.022)and the expression of ADA before chemotherapy(P<0.001)were independent risk factors of overall survival.(4)Of 76 patients with CRPC,40 patients was in high group(Cys C>1.61 mg/L),36 in low(Cys C?1.61 mg/L).There was a significant difference between the two groups in TNM staging,baseline PSA and distant metastasis(P<0.05),but no association was observed with the age,Gleason score,number of chemotherapy cycles and PSA response(P>0.05).(5)The median PFS of high ADA group and low ADA group were 12 and 16 months,and the difference was statistically significant(P=0.008).The median overall survival time were 15 and 22 months,and the difference was statistically significant(P<0.001).(6)Univariate analysis showed that TNM stage,baseline PSA,number of chemotherapy cycles,distant metastases,PSA response and the expression of Cys C before chemotherapy were associated with the survival time of patients with CRPC(P<0.05).COX multivariate analysis showed that the number of chemotherapy cycles(P=0.013),the PSA response(P=0.011)and the expression of Cys C before chemotherapy(P=0.002)were independent risk factors of progression free survival of patients with CRPC.The number of chemotherapy cycles(P=0.016)and the expression of Cys C before chemotherapy(P=0.001)were independent risk factors of overall survival.(7)Through the detetion of ADA and Cys C before chemotherapy,the low expression of ADA and high Cys C group has a poor prognosis.The median PFS and overall survival time are 10 months and 17 months.The differences between four groups was statistically significant(P<0.001).Conclusion:(1)The expression of ADA before chemotherapy may be related with the tumor distant metastasis,and the decreased expression may lead to poor prognosis of CRPC.(2)The expression of Cys C before chemotherapy may be related with the tumor differentiation,metastasis and load,and the increased expression may lead to poor prognosis of CRPC.(3)The expression of ADA and Cys C before chemotherapy are independent risk factors for prognosis of CRPC patients and can be regarded as effective indicators to assess the prognosis of CRPC.