Creatine - A New Biomarker Of Prostatic Cancer And Its Diagnostic Threshold

In recent years,themorbidity and mortality of prostate cancer(PCa)is gradually increased.Therefore,it is particularly importantfor the early screening and diagnosis of prostate cancer.PSA screening is considered to be the best predictor of prostate cancer,and is widely used clinically.But it is limited for its specificity.Some patients with benign prostatic hyperplasia and prostatitis PSA also increased.False-positive and false-negative conditions are still common,especially in the "gray area"(PSA 4-10 ng/m L).In this study,sarcosine as a biomarker of prostate cancer and can be expected to be invasive.More importantly,the existing diagnostic methods often make it easy for clinical oncologists to diagnose prostate cancer,but can not determine the biological characteristics of cancer cells is invasive or non-invasive.Sarcosine in this study will be the early diagnosis of prostate cancer is of great significance.Objective: To establish a method for the determination of urinary sarcosine in Chinese healthy population by using liquid chromatography-tandem mass spectrometry(LC-MS / MS).Prostate cancer,and verify the feasibility of sarcosine as a biomarker for the diagnosis of prostate cancer.Methods: This study established a method for the determination of sarcosine(creatinine)and creatinine concentration in human urine by liquid chromatography-tandem mass spectrometry.The method was applied to detect sarcosine and creatinine,and had good specificity,accuracy precision,gree and sensitivity.329 cases of male patients who were not admitted to the prostate cancer and 167 patients with prostate cancer were enrolled in the Department of Urology,Xuhui District Central Hospital,Shanghai.Results: The accuracy,specificity,residual,extraction recovery,medium effect and stability of the analytical method were in accordance with the requirements.The levels of urinary sarcosine(mg/g creatinine)in the healthy population were(0.115 ± 0.077)mg/g creatinine in the healthy population and 167 patients with prostate cancer were(0.797 ± 0.909)mg/g creatinine,the median of 0.426mg/g creatinine.The median urinary creatinine(mg/g creatinine)level was(0.797 ± 0.909)mg / g creatinine in patients with prostate cancer.Conclusion: Urinary sarcosine levels in patients with prostate cancer were significantly higher than those in healthy subjects(p<0.001,t-test).The normal reference range for urinary sarcosine was set to <0.264 mg/g creatinine.Considering that the degree of urinary sarcosine in patients with prostate cancer is relatively large,a more stringent 99% percentile of urinary sarcosine,or 0.356 mg/g creatinine,is recommended for clinical diagnosis as a diagnostic threshold for prostate cancer.The area under the ROC curve of urinary sarcosine was 0.898(95%CI 0.866-0.930,p<0.001).It was found that urinary sarcosine had a high diagnostic value for prostate cancer.Compared with localized prostate cancer,urinary sarcosine levels in metastatic prostate cancer weresignificantly higher(p<0.001).In the high degree of malignancy,urinary creatinine levels in the death cases were significantly increased.Urinary sarcosine levels are important for distinguishing prostate cancer malignancy,metastatic,and predictable clinical survival,and can characterize the invasive and progression of prostate cancer,noninvasive biomarkers.