The Effects Of Prostate Volume,age And Type 2 Diabetes On The Diagnostic Efficiency Of Prostate Specific Antigen To Detect Prostate Cancer

Background:Prostate specific antigen(PSA)remains the mainstay of early prostate cancer(PCa)detection.However,multiple factors in addition to cancer influence PSA,thus the diagnostic efficiency of PSA to detect prostate cancer remains controversial.Recently,several studies have demonstrated that prostate volume,age and 2 diabetes mellitus(T2DM)have impact on serum PSA.Whether prostate volume,age and T2DM affect the diagnostic efficacy of PSA is a clinical issue worth exploring.Objective:To investigate the impact of prostate volume,age and T2DM on the diagnostic efficiency of PSA to detect prostate cancer.Methods:503 consecutive patients who received prostate puncture biopsy in the Department of Urology in our hospital from June 2014 to May 2018 were included.Clinical data including patient age,prostate volume,history of T2DM,serum PSA and pathological data were collected.According to the age,patients were divided into age)70 group and age<70 group.According to the prostate volume(PV)parameter,patients were divided into PV≤50ml group and PV>50ml group.Based on the history of T2DM,patients were divided into type 2 diabetes(T2DIM)group and non-diabetes(NT2DM)group.Spearman’s correlation analysis and Mann-Whitney U test were used to analyze the correlation between PV,age or T2DM and the serumPSA,and ROC curves were established to further explore the effects of the above factors on the diagnostic efficacy of PSA screening for prostate cancer.Results:Serum PSA levels in the whole group increased with age(r=0.16;P<0.001).However,there was no significant correlation between PSA level and age parameter in PCa subgroup and BPH subgroup(all P>0.05).Further stratified analysis was penrfonmed according to age and pathological type.Among the patients in the whole group,serum PSA was significantly higher in the age≥70 group than that in the age<70 group(P=0.015),while in the PCa subgroup and BPH subgroup,no significant difference in PSA levels was observed between age≥70 group and age<70 group(both P>0.05).Among the patients in the whole group,there was no significant correlation between PV and serum PSA(P=0.12).Whereas,there was a significant positive correlation between PV and serum PSA in both PCa subgroup and BPH subgroup(PCa group:r=0.325,P<0.001;BPH group:r= 0.141,P=0.038).Further stratified analysis based on PV parameter and pathological type showed that,among PCa patients,serum PSA level in the PV>50 ml group was significantly higher than that in the PV≤50 ml group(P<0.001),whereas no significant difference in serum PSA levels was found between the two groups among all the patients and the patients of BPH subgroup(both P>0.05).According to the stratified analysis based on T2DM and pathological type,serum PSA level in T2DM patients were significantly lower than that in NT2DM patients both in the whole group,PCa subgroup and BPH subgroup(both P<0.05).After further adjusting the determinant factors of PSA by covariance analysis,the results showed that prostate volume was an independent determinant factor for serum PSA,while age and T2DM had no significant effect on serum PSA.To verify the effect of above factors on the diagnostic efficacy of PSA,the ROC curve was drawn.The results showed that the area under the curve of PV>50ml group(AUC = 0.868,95%CI:0.812-0.924)was significantly higher than of PV≤50ml group(AUC = 0.761,95%CI:0.696-0.827;P=0.015).The positive predictive value and negative predictive value of PV>50ml group were 90.6%and 69.8%,respectively.The positive predictive value and negative predictive value of PV≤50ml group were 78.8%and 63.0%respectively.Besides,there was no significant difference in AUC between the T2DM group and the NT2DM group.No statistical difference in the AUC was observed between the age≥70 group and the age<70 group(all P>0.05).Conclusion:Prostate volume parameter and type 2 diabetes both affected serum PSA levels,of which prostate volume parameter was the independent determinant factor of PSA.Prostate volume significantly changed the diagnostic efficacy of PSA to detect prostate cancer,suggesting the necessity of stratified screening for prostate cancer based on different populations.Clinical application of PSA in the population of prostate volume less than 50ml should be more cautious.