Kiwi researchers have found a new way to reveal tiny traces of cancer in the body, in a million-dollar study that could allow clinicians to find and treat tumours while still barely detectable.

Doctors hunting for evidence of cancer in samples often face a needle-in-a-haystack scenario, with cancer cells hidden among a sea of normal cells.

For the past few years, leading New Zealand cancer researcher Professor Parry Guilford has been investigating how these faint traces can be picked out of the mix - and has now discovered a promising solution.

Guilford, director of Otago University's Centre for Translational Cancer Research, said earlier detection of cancer was critical, as it could mean the difference in patients surviving the disease, which accounts for nearly a third of all deaths in New Zealand.


"If you can detect very small cancers and treat them at this very early stage, the cure rate can be higher than 95 per cent - but this can fall away to 10 percent five-year survival rates for advanced cancers," he said.

"So what we are doing is pushing into those very small tumours."

Guilford used a million-dollar, three-year Health Research Council grant to identify cancer cells in a range of body fluid samples.

"In the case of bladder cancer, you'll find a lot of cells will fall off the wall of the normal bladder and you'll also get cells that fall off the tumour, and you'll get both of these cell types ending up in your urine sample.

"This means that if your tumour is small, the background noise from the normal cells can hide the signal from those tumour cells."

The approach he has developed centred not on studying all of the cells from a sample at once, but feeding cells individually through the wells of a high throughput polymerase chain reaction (PCR) plate and then analysing each separately.

"By doing that we've been able to get proof of principle, that in fact, we can actually use this to see a rare cancer cell in a sea of normal cells," Guilford said.

"So we think it's got the potential to be used to improve test sensitivity."

Another benefit of the method was that it had the potential to distinguish benign cells that confusingly appeared like cancer cells, such as those involved in wound healing, thereby improving test specificity.

While the study had been carried out in the context of bladder cancer, Guilford said it could be applied to many cancers, including prostate cancer and endometrial cancer, and key killers lung cancer and colon cancer.

The test could be performed using standard biological samples, including urine and stool samples, or vaginal swabs.

Guilford, who is now is writing up the study results, said the next step was to refine how the approach could be quickly and easily used in clinical settings.

"It won't be a lot faster than current methods, but should still have a reasonable turn-around time," he said.

"Most importantly, it opens up the game to look at a lot more markers that could be used to diagnose the disease and all its subtypes."

Cancer Society NZ chief executive Claire Austin said it was great to see Kiwi researchers leading the way with ground-breaking research.

"Research that increases early detection is another great step in the right direction and the Cancer Society of New Zealand are encouraged by research that can translate into assisting better clinical diagnosis," Austin said.

"It may sound obvious, but the earlier you can diagnose and start to treat different cancers, the better the outcomes will often be.

"This is particularly relevant for those that are currently difficult to pick up early such as lung cancer."

Cancer breakthroughs "a blessing" - Sir Peter Leitch

It wasn't a groundbreaking diagnostic test that probably saved the life of Sir Peter Leitch, but a good doctor and a good specialist.

"If they hadn't got it, who knows, I could have been done for," said the Mad Butcher, now in remission after beating back a rare and aggressive form of bladder cancer that his brother had died from.

But the diehard Warriors fan said anything that could combat cancer was a blessing.

"It's a very scary word, cancer, when you're told you've got it. And I'm certainly not a doctor, but the one thing I know is the sooner they find it, the better chance you are of getting it treated."

Bladder cancer accounts for around three percent of cancer diagnosed in New Zealand each year, typically affects people over 60 years of age, and is more common in men than women.

Still, the 72-year-old thought he'd never have to be confronted with it.

"I never expected to get bloody cancer. Not in a million years.

"Mate, I only checked it because I felt funny down below, and through the doctor being thorough, he sent me to a urologist and we picked it up very promptly."

The journey had changed his life.

"I think I'm more grateful to be alive now. You tend to take being alive for granted."

It had also opened his eyes to the leading clinicians and researchers fighting it.

"We do have some wonderful people in the country that we have to be very thankful for."

Protein could stop breast cancer spread

Meanwhile, a team of Kiwi scientists have begun investigating a protein that could be the key to stopping the spread of breast cancer to other parts of the body.

The Massey University and international researchers are focusing on Heterochromatin Protein 1a, or HP1a, which is involved in suppressing cellular invasion, the first step in metastasis of cancer.

"The protein is often lost in metastatic tumours, therefore understanding the role this loss plays in allowing a cell to become invasive will identify potential targets for the next generation of anti-cancer therapies," said Massey's Dr Tracy Hale, who is leading the just-funded study.

"When these cancer cells invade, their nucleus must become more malleable to allow them to squeeze through their surrounding environment and we believe the presence or absence of the protein controls this process and ultimately dictates whether the cancer spreads or not."

Hale said the research could apply to a number of cancers, but its importance for breast cancer patients was immense as it has been found that they were at a greater risk of metastasis than other sufferers.

The two-year study received a $200,000 grant from the joint Breast Cancer Research in New Zealand initiative, including the New Zealand Breast Cancer Foundation and Health Research Council of New Zealand (HRC).

"The latest scientific developments indicate that the most effective treatments for breast cancer in the future will focus on targeted treatments and immune therapies that are tailored specifically for individual types of breast cancer," said HRC chief executive, Professor Kath McPherson.

"This initiative is focused on these areas of research because we believe they offer the best chance to significantly improve breast cancer treatment and survival rates."