Normalization of Urinary Pteridines by Urine Specific Gravity for Early Cancer Detection
Background: Urinary biomarkers, such as pteridines, require normalization with respect to an individual's hydration status and time since last urination. Conventional creatinine-based corrections are affected by a multitude of patient factors whereas urine specific gravity (USG) is a bulk specimen property that may better resist those same factors. We examined the performance of traditional creatinine adjustments relative to USG to six urinary pteridines in aggressive and benign breast cancers. Methods: 6-Biopterin, neopterin, pterin, 6-hydroxymethylpterin, isoxanthopterin, xanthopterin, and creatinine were analyzed in 50 urine specimens with a previously developed liquid chromatography-tandem mass spectrometry technique. Creatinine and USG performance were evaluated with non-parametric Mann-Whitney hypothesis testing. Results: USG and creatinine were moderately correlated (r= 0.857) with deviations occurring in dilute and concentrated specimens. In 48 aggressive and benign breast cancers, normalization by USG significantly outperformed creatinine adjustments which marginally outperformed uncorrected pteridines in predicting pathological status. In addition, isoxanthopterin and xanthopterin were significantly higher in pathological specimens when normalized by USG. Conclusion: USG, as a bulk property, can provide better performance over creatinine-based normalizations for urinary pteridines in cancer detection applications.
C. Burton et al., "Normalization of Urinary Pteridines by Urine Specific Gravity for Early Cancer Detection," Clinica Chimica Acta, vol. 435, pp. 42-47, Elsevier, Aug 2014.
The definitive version is available at http://dx.doi.org/10.1016/j.cca.2014.04.022
Keywords and Phrases
Breast Cancer; Creatinine; Pteridine; Renal Dilution; Urine Normalization; Urine Specific Gravity; 6 Biopterin; 6 Hydroxymethylpterin; Isoxanthopterin; Neopterin; Pterin; Pterin Derivative; Tumor Marker; Unclassified Drug; Xanthopterin, Aged; Bulk Density; Cancer Diagnosis; Clinical Article; Controlled Study; Creatinine Urine Level; Early Diagnosis; Female; Human; Liquid Chromatography; Priority Journal; Renal System Parameters; Tandem Mass Spectrometry; Urinalysis; Urine Density; Very Elderly
International Standard Serial Number (ISSN)
Article - Journal
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