Editor's Commentary - Sarcosine in prostate cancer tissue is not a differential metabolite for prostate cancer aggressiveness and biochemical progression

BERKELEY, CA (UroToday.com) - Biomarkers to differentiate benign from malignant tissue and stratify indolent from aggressive cancers are the subject of much research effort in prostate cancer (CaP).

Metabolomics have identified differential metabolites in CaP tissue and in a Nature publication in 2009 it was reported that sarcosine is associated with CaP progression. In the February, 2011 edition of the Journal of Urology, a group of European researchers compared sarcosine levels in matched malignant and benign prostate tissues from the same prostatectomy specimens. They also correlated sarcosine concentration with prognostic indicators; tumor grade, stage and PSA recurrence and estimated the potential of sarcosine as a predictor of tumor progression.

Prostatectomy specimens from 92 patients obtained between 2001 and 2007 were studied. Clinicopathological data was recorded and PSA recurrence was defined as a PSA >0.2ng/ml with 1 subsequent increasing value. Sarcosine was measured in tissue by gas chromatography-mass spectroscopy and normalized. Patients were stratified by tumor stage pT2 and pT3 and by tumor Gleason score <7 vs. 7 vs. ≥7. Sarcosine levels were 7% higher in malignant compared with benign tissue. There was no statistically significant difference with relation to tumor stage or Gleason score. Median sarcosine levels did not differ among men with Gleason score 7 tumors and PSA <10ng/ml or >10ng/ml. Furthermore, sarcosine levels in malignant tissue did not correlate with patient age, preoperative PSA, percent free to total PSA, prostate volume, tumor stage or tumor grade. There was poor discriminative ability for sarcosine to differentiate between malignant vs. benign tissue. Also, sarcosine did not differentiate between Gleason score <7 or >7 or patients with or without biochemical recurrence. When included with clinicopathologic variables in multivariate analysis, sarcosine did not improve the prognostic impact and was not an independent variable.

Jentzmik F, Stephan C, Lein M, Miller K, Kamlage B, Bethan B, Kristiansen G, Jung K.

J Urol. 2011 Feb;185(2):706-11

PubMed Abstract
PMID: 21168877

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