Study's aim: test to find men's cancer really early

Photo / Thinkstock

A prostate test which could detect a single cancer cell passed in urine has been given a $800,000 funding boost.

University of Otago researchers plan to develop a highly sensitive test which will improve the accuracy of early cancer detection and provide an alternative to the conventional, "unpleasant" method of testing.

A biochemistry team led by Professor Parry Guilford already has a successful urine test for bladder cancer on the market.

Professor Guilford said this screening test had around 85 per cent sensitivity and might not detect tiny tumours.

The new research - backed by the Health Research Council of New Zealand (HRC) grant - aimed to improve detection in the remaining 15 per cent of a sample.

The analysis of urine samples is a needle-in-the-haystack process, because cancer cells are hidden amid a cloud of normal cells.

"You analyse that whole sample and all the cells are mixed up together. If it's a cancer patient it will contain a small number of cancer cells and quite a few normal cells as well. If the tumour is very small, that normal background will hide the signal from the tumour."

Detection was even more difficult in people with urinary tract infection, kidney stones or bladder stones, because their bodies produced a greater number of normal cells.

Technological leaps in the amplification of DNA now allowed biochemists to zero in on a single cell as small as a millionth of a metre.

The Otago researchers will separate all the cells in a urine sample and analyse them one by one.

"If there's even one single tumour cell in there in a sea of 999 normal cells, we'll still see it," said Professor Guilford. "It gives us the power to have extremely high sensitivity for detecting bladder cancer."

He believed the same principle could be applied to prostate cancer. Prostate cancer gives out 100 times fewer cells, so is even harder to detect.

HRC chief executive Robin Olds said: "Cancers of the bladder and prostate are very treatable if detected early. A highly accurate, non-invasive screening test like this will undoubtedly prevent some needless deaths."

Professor Guilford said a simple urine test was far less daunting than the conventional methodof placing an endoscope inside the urinary tract: "Obviously that's not great for most people - they found it rather invasive and unpleasant."

People who had been treated for bladder cancer had a high risk of recurrence, and must undergo this uncomfortable process every three to six months, he said.

His team was also awarded $1.2 million to continue work on drugs that were selectively lethal to cancer cells.

In yesterday's funding announcement, the HRC distributed $74.5 million in grants to 173 successful applications.

ON THE WEB

www.hrc.govt.nz