Metabonomic diagnosis of bladder cancer: what are the advantages and considerations?

Abstract

Bladder cancer (BC) is the fifth most common cancer and is one of the leading causes of death worldwide [1]. The 5-year survival rate for BC is approximately 94% if detected early; thus timely diagnosis and intervention of BC increase patient’s survival rate dramatically [2]. However, BC has a high recurrence rate and patients are subjected to life-long surveillance. As a result, the lifetime economic burden per BC patient is higher than other cancer types. Currently, the standard diagnoses of BC are cystoscopy and urinary cytology [3]. While cystoscopy is clinically reliable, it is expensive, invasive and associated with a definite risk of morbidity. On the other hand, noninvasive urinary cytology demonstrates poor sensitivity in detecting low-grade BC (4–31%) [4]. In recent years, several proteinaceous urinebased bladder tumor markers (UBBTMs) have been evaluated for the diagnosis of BC, such as bladder tumor antigen (BTA), NMP22, FDP and ImmunoCyt [5]. However, the specificity and sensitivity of current molecular biomarkers are not adequate to replace cystoscopy [6]. Therefore, there is an impetus to develop sensitive and specific noninvasive biomarkers for the diagnosis and surveillance of BC. Dysregulated molecular pathways, associated with tumor genes, secrete specific modulated levels of metabolites into biological fluids that may be detectable prior to clinical symptoms, rendering them potential early biomarkers for cancer diagnosis. Metabonomics measures the dynamic multiparametric responses of systems biological metabolome to genetic modifications or pathophysiological stimuli such as cancers [7]. It allows scientists to survey global dysregulated metabolic pathways and gain holistic insights into cancer etiology and progression. Significant progress has been made using modern metabonomics techniques to characterize BC patients, identify marker metabolites and generate new knowledge in disease biology and potential therapeutic targets [5].