Serum sarcosine increases the accuracy of prostate cancer detection in patients with total serum PSA less than 4.0 ng/ml.

Abstract

BACKGROUND:

Sarcosine is reported to be a differential metabolite that is greatly increased during prostate cancer (PCa) progression. In this study, we assessed the role of serum sarcosine as a biomarker for PCa, as well as any association between sarcosine levels and clinical-pathological parameters.

METHODS:

Sarcosine was measured by fluorometric assay in serum samples from 290 PCa patients and 312 patients with no evidence of malignancy (NEM), confirmed by 8-12 core prostate biopsies. Nonparametric statistical tests and receiver operating characteristics (ROC) analyses were performed to assess the diagnostic performance of sarcosine in different (prostate-specific antigen) PSA ranges.

RESULTS:

ROC analyses in subjects with PSA < 4 ng/ml showed a higher predictive value of sarcosine (AUC = 0.668) versus total PSA (AUC = 0.535) (P = 0.03), whereas for the other two PSA ranges (4-10 ng/ml and >10 ng/ml), percent ratio of free to total PSA (%fPSA) showed a predictive superiority over sarcosine. Moreover, in patients with a PSA < 4 ng/ml, the percentage of low/intermediate-grade cancers was positively associated with sarcosine levels (P = 0.005). The specificities for serum sarcosine, %fPSA, PSA, and the logistic regression model at 95% sensitivity were 24.4, 3.41, 2.22, and 28.4%, respectively.

CONCLUSIONS:

We provide evidence that serum sarcosine has a higher predictive value than tPSA and %fPSA in patients with PSA < 4 ng/ml. Moreover, sarcosine levels were significantly different in low grade versus high grade cancers in this subset of patients, suggesting that this marker may be a further tool not only for diagnosing PCa in normal PSA and abnormal DRE/TRUS patients but also for selecting candidates for non-aggressive therapies and active surveillance.

• Authors: Giuseppe Lucarelli, Margherita Fanelli, Angela Maria Vittoria Larocca, Cinzia Annatea Germinario, Monica Rutigliano, Antonio Vavallo, Francesco Paolo Selvaggi, Carlo Bettocchi, Michele Battaglia, Pasquale Ditonno
• Journal: The Prostate (Prostate) Vol. 72 Issue 15 Pg. 1611-21 (Nov 2012) ISSN: 1097-0045 [Electronic] United States
• PMID: 22430630 (Publication Type: Journal Article)
• Copyright: Copyright © 2012 Wiley Periodicals, Inc.

Chemical References

• Biomarkers, Tumor
• Prostate-Specific Antigen
• Sarcosine

Topics

• Adenocarcinoma (blood, diagnosis)
• Adult
• Aged
• Aged, 80 and over
• Biomarkers, Tumor (blood)
• Biopsy
• Case-Control Studies
• Disease Progression
• Humans
• Male
• Middle Aged
• Neoplasm Grading
• Neoplasm Staging
• Predictive Value of Tests
• Prospective Studies
• Prostate-Specific Antigen (blood)
• Prostatectomy
• Prostatic Neoplasms (blood, diagnosis)
• ROC Curve
• Reproducibility of Results
• Sarcosine (blood)