According to researchers, a new 3-minute test could help in diagnosing prostate cancer. Prostate cancer is one of the most common types of cancer in men, affecting about one in six men in the United States.

The researchers have developed the test by using light energy to measure the level of citrate in fluid samples from the prostate gland. The technique could provide the basis of a rapid means of detecting prostate cancer in the future.

Almost a quarter of male cancers in the UK are diagnosed as prostate cancer and more than 10,000 men die from the prostate cancer each year. There will be an estimated 192,280 new cases of prostate cancer, and an estimated 27,360 men will die from prostate cancer in the US in 2009.

Scientists, led by Prof David Parker from Durham University's Chemistry Department, have worked with experts from the University of Maryland, USA to develop the technique that measures the wavelength of light as it is shone through diluted samples of body fluids.

The research team believes that the technique which can measure, with speed and accuracy, how citrate levels fall in the prostate gland as cancer develops, could also find use for the diagnosis of other medical conditions, associated with poor kidney function.

Prof Parker said: "Citrate provides a significant biomarker for disease that may provide a reliable method for screening and detecting prostate cancer, and for the monitoring of people with the disease. This technique could form the basis of a simple screening procedure for prostate cancer that could be used in outpatient departments at local hospitals."

His team has shone light into over 100 different chemical structures to see how they function and respond to the presence of certain important bioactive species. They have looked particularly closely at how citrate and lactate bind to luminescent structures within fluids. Citrate and lactate are vital for our bodies' metabolism for normal function. Citrate provides energy for cells and the amount found in the prostate varies considerably due to an enzyme called m-aconitase which transforms it. This enzyme is very sensitive to zinc and, in prostate cancer sufferers, zinc levels are depressed and the enzyme switches on again.

Prof Leslie Costello from the University of Maryland said: "Citrate is formed in cell metabolism processes which alter as cancers grow. The analysis of the citrate concentration of prostatic fluid can provide an accurate way to screen and diagnose prostate cancer. Since citrate concentrations decrease markedly early in malignancy, this technique makes it possible to analyze what's happening quickly in the early and treatable stage of prostate cancer. It shows much promise as a clinical tool."

The new test requires only a microlitre of fluid and the sample can be easily measured in an optical instrument. Using samples from male volunteers, the researchers have developed a portable instrument that can give results in 3 minutes.

The team's challenge has been how to accurately measure changes in the amount of citrate or lactate in fluid samples using the technique. The early results are promising and the team intends to look at the analysis of other body fluids. A possible way forward is to examine the citrate levels in seminal fluid samples, which are made up of 50% prostate fluid.

The team has looked at 20 samples so far and verified the analysis in every case. The next stage is to work with a local hospital and examine samples from 200 volunteers to see whether the first Durham results correlate.

Prof Parker says: "It's been a complex process to develop the technique but we're very optimistic about it. Ultimately, this could provide an accurate method of screening for prostate cancer in men that could be carried out in 3-minutes once a biopsy has been obtained from the patient at a hospital outpatient department."

Process for testing:

The sample is taken from the prostate gland, this is part of the biopsy procedure during clinical analysis in urology.
References:
1. David Parker, et al. Durham University.
2. National Cancer Institute.