The research team measured sarcosine levels in urine samples from 106 patients known to have prostate cancer and from 33 other patients with no evidence of malignancy (NEM), confirmed by 8-12 core prostate biopsies, after standardized digital rectal examination (DRE). They also measured sarcosine levels from the urine of 12 healthy men and women. They then correlated their findings to data on prostate volume, tumor stage, Gleason score, and PSA level from the same patients.
The results of this study showed the following:
The median sarcosine-creatinine ratio in urine was 13 percent lower in the prostate cancer patients than in patients with NEM.
Sarcosine values were not associated with tumor stage (pT2 vs pT3) or grade (Gleason score < 7 vs ≥ 7).
The ability to discriminate between prostate cancer patients and patients with NEM was not improved by sarcosine in comparison with total PSA, and it was significantly worse than the percent free PSA.
The authors conclude that sarcosine in urine after DRE cannot be considered as a suitable marker to differentiate between patients with and without prostate cancer. They also note that the higher number of prostate cancer patients in this study, as compared tom the number of patients with NEM, has no impact on the findings of the research.