12 Feb 2009 01:00 PM
Scientists Hopeful Of Simple Urine Test For Prostate Cancer
US scientists have found that a molecule called sarcosine, a byproduct of metabolism that is eliminated via urine, could be an effective marker for
prostate cancer and that simple urine tests that measure concentrations of this marker might one day reduce the need for invasive biopsies.
The research behind the discovery is written up as an article in the 12 February issue of Nature, and was the work of Dr Christopher Beecher at the University of Michigan in Ann Arbor, and a large team of colleagues, including researchers from other centers in the US.
For this study, the researchers inspected metabolites (byproducts of natural chemical reactions in the body) in 262 samples from prostate cancer patients who were at various stages of the disease, so that samples ranged from containing benign cells to aggressive metastized tumors that had already spread to other organs. As cancers progress from early to late stages, the concentration of metabolites associated with these changes vary.
Scientists already have a list of "likely suspects" for metabolic byproducts that could indicate changes in prostate cancer progression, but what is special about this study is that Beecher and colleagues decided to widen their search to include all the metabolites present in the samples they had, including some that were not considered "likely suspects". They were able to do this because they used mass spectrometry, which picks up all the molecules in a sample and presents a unique signature for each one.
And, as often happens in science, the result was a complete surprise, because the best contender was not among the "likely suspects".
As Beecher explained to Nature News:
"We would never have expected to see sarcosine, nor would we have expected to look for it."
Sarcosine is a byproduct of the amino acid glycine. Beecher and colleagues actually found at least 6 metabolites that were present in higher concentrations in the more advanced metastatic cancer samples compared to samples of earlier stages of the disease, but sarcosine was by far the highest…
The research behind the discovery is written up as an article in the 12 February issue of Nature, and was the work of Dr Christopher Beecher at the University of Michigan in Ann Arbor, and a large team of colleagues, including researchers from other centers in the US.
For this study, the researchers inspected metabolites (byproducts of natural chemical reactions in the body) in 262 samples from prostate cancer patients who were at various stages of the disease, so that samples ranged from containing benign cells to aggressive metastized tumors that had already spread to other organs. As cancers progress from early to late stages, the concentration of metabolites associated with these changes vary.
Scientists already have a list of "likely suspects" for metabolic byproducts that could indicate changes in prostate cancer progression, but what is special about this study is that Beecher and colleagues decided to widen their search to include all the metabolites present in the samples they had, including some that were not considered "likely suspects". They were able to do this because they used mass spectrometry, which picks up all the molecules in a sample and presents a unique signature for each one.
And, as often happens in science, the result was a complete surprise, because the best contender was not among the "likely suspects".
As Beecher explained to Nature News:
"We would never have expected to see sarcosine, nor would we have expected to look for it."
Sarcosine is a byproduct of the amino acid glycine. Beecher and colleagues actually found at least 6 metabolites that were present in higher concentrations in the more advanced metastatic cancer samples compared to samples of earlier stages of the disease, but sarcosine was by far the highest…
