A team of cancer researchers in Korea believes a simple new diagnostic method may revolutionize bladder cancer diagnosis and prognosis.
The team from the Natural Product Research Institute at Seoul National University tested an advanced and sensitive method of analyzing metabolites in the urine of 138 bladder cancer patients. Metabolites are substances produced during metabolism. Digestion is an example of a metabolic process that produces metabolites, which end up in the urine.
To test the accuracy of the metabolite analysis method of bladder cancer diagnosis, the metabolic profiles of the 138 cancer patients were compared with those of 121 control subjects, including 69 healthy people and 52 people who had blood in their urine because of non-cancerous conditions. Among the Korean test subjects, the metabolite urine test made it possible for the scientists to not only pinpoint which patients had bladder cancer, but also to predict their likelihood of survival.
“Multivariate statistical analysis revealed that the cancer group could be clearly distinguished from the control groups on the basis of their metabolomics profiles, even when the hematuric [blood in the urine] group was included,” writes lead author Xuan Jin in the journalOncotarget.
The test, called a high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS), identified 12 metabolites that were different between the bladder cancer patients and the healthy patients. Many of them were found to be related to glycolysis (the process that turns sugar into energy) and beta-oxidation (the breakdown of fatty-acid molecules). The test also had the ability to accurately distinguish bladder cancer patients with the more advanced, muscle-invasive form of the disease from those whose cancer was contained inside the bladder.
Bladder cancer diagnosis is often done by cystoscopy, an imaging procedure which involves putting a special camera into the bladder, and by cytology, which tests for cancer cells in the urine. The new metabolite test was able to identify bladder cancer with 91.3% accuracy. Further analysis found that specific metabolomics profiles could also be correlated with bladder cancer survival times, offering a way for doctors to better predict prognosis.
The team concludes their study summary by suggesting that, because of its simplicity and accuracy, this new kind of urine test has the potential to “augment or even replace the current modalities for bladder cancer diagnosis”. More than 70,000 people are diagnosed with bladder cancer in the U.S. each year. People with diabetes – especially those who have taken the drug Actos – are at elevated risk for the disease.
Jin, X et al, “Diagnosis of bladder cancer and prediction of survival by urinary metabolomics”, February 17, 2014, Oncotarget, Epub ahead of print.