A bowel cancer screening scheme in north and west Auckland has led to a huge advance in early diagnosis of the potentially fatal disease.
This is the point of asking 130,000 people aged 50 to 74 to take a pooh sample to be tested for invisible traces of blood - and it certainly appears to be working well in the Waitemata health district.
Preliminary results show 44 per cent of patients diagnosed with bowel cancer in the pilot screening programme had stage-one disease.
About 95 per cent of patients in whom the disease is detected this early would be alive in five years, said the programme's clinical director, Dr Mike Hulme-Moir.
A study in the NZ Medical Journal in 2009 - two years before the pilot started - found only 28 per cent of New Zealand bowel cancer patients had been diagnosed with "localised" cancer. This revealed how badly New Zealand was doing without systematic screening compared with Britain, where the figure with such screening was 42 per cent.
Dr Hulme-Moir further explains: "Some stage-one cancers are so early we can treat them just with colonoscopy."
Colonoscopy involves use of a viewing tube equipped with a tiny video camera and surgical instruments to remove potentially pre-cancerous "polyps", and sometimes to remove cancerous tumours. Open surgery to remove any tumour is more invasive, dearer and riskier.
So if it's all going well at Waitemata, why not create a national screening programme to deal with New Zealand's unfortunate status of having one of the developed world's highest rates of bowel cancer.
The Labour Party says it would move towards a New Zealand-wide programme, retaining the Waitemata scheme for people aged 50 to 74, and at first extending it to 50- to 64-year-olds in Waikato and Southland-Otago, two areas with bowel cancer death rates higher than the New Zealand average between 2006 and 2008.
Leader David Cunliffe says screening reduces the bowel cancer death rate by at least 15 per cent and could prevent about 180 deaths a year.
But Health Minister Tony Ryall says going nationwide is premature and could create a faulty screening programme harmful to patients.
He acknowledges a national screening programme is inevitable, but stands by his plan to let the Waitemata pilot run its four-year course until 2015 and have it fully evaluated before decisions are made on a national scheme.
He says New Zealand does not have enough health workers to do the extra colonoscopy work.
"We don't have a workforce sufficient to undertake the [extra colonoscopy] work and all our experience in New Zealand is that screening programmes should be trialled and fully evaluated and understood before a national roll-out. That's the best way to ensure patient safety."
But others say such problems can be solved along the way in setting up a national programme.
Labour's associate health spokesman, Iain Lees-Galloway, says the Government's health workforce agency can't determine how quickly new colonoscopy staff will have to be recruited and trained until it is told the timeframe for a national programme.
"Labour has said it will set up an implementation plan to ensure the resources are in place as it rolls out the programme."
Beat Bowel Cancer Aotearoa and other cancer groups support Labour's plan for an immediate start on setting up a national programme.
This is despite evidence the public health system can't cope with the existing demand for colonoscopies.
Megan Smith, chief executive of the charity - which starts Bowel Cancer Awareness Month on Sunday - criticises the Government for not meeting its own targets on maximum colonoscopy waiting times.
Under national standards, urgent cases are meant to have their colonoscopy within two weeks. The ministry says its latest figures show 49.6 per cent of urgent cases had the procedure within two weeks, "and the remainder generally within four weeks".
"Just under a third - 30.2 per cent - of those requiring semi-urgent colonoscopies receive them within the six weeks guideline."
The number of colonoscopies has increased by 20 per cent in the past five years and extra funding will help reduce waiting times. A one-off $3.5 million was given to district health boards this year to increase the number of colonoscopies they do, plus $8 million in the Budget, and $1.8 million to improve colonoscopy services.
But Ms Smith also says the claimed lack of capacity may not be as bad as it seems, citing presentations at a meeting hosted by the ministry.
"One topic was the potential to increase training for people interested in doing colonoscopy ... That's a long-term strategy and we have got an immediate problem now."
She said private hospitals had said they could perform colonoscopies on publicly funded patients. "I'm not suggesting complete outsourcing but it's no different from the radiation oncology problem we had when patients were sent to Australia."
But while politicians and charities argue about the path to a national programme, Waitemata is trying to extend the reach of its scheme.
Uptake of the at-home screening, at 55 per cent returning a correctly completed kit , is a little short of the 60 per cent target but considered good for a new programme. The response rate of Maori, at 42 per cent, is a worry, and for Pasifika, at 26 per cent, is poor.
Twelve per cent of returned test kits are not completed correctly - often through mistakes in filling out the forms - although when these people have a second attempt, most get it right.
A study for the ministry suggested the low Maori and Pacific uptake rates were partly to do with opposition to having to collect, package and post faecal samples and that having walk-in clinics for testing might help.
However this is considered nonsense by Maori health expert Dr Nina Scott, a bowel screening adviser to the ministry who says all cultures have a distaste for handling faeces.
"I think blaming it on culture is a pretty poor excuse. It's victim-blaming."
She says what's needed is to refine the techniques for inviting Maori and Pacific people into the programme and to learn from high-performing providers in the national breast and cervical cancer screening schemes, some of which achieve Maori and Pacific coverage of 80 to 90 per cent.
"There's no way we can roll out a national programme while we have these inequities. We need to sort these inequities out first. We can do it."
' I dodged a bullet. I had no symptoms'
Brent Wray had no signs that a tumour was growing inside him until he joined the trial bowel screening programme.
"I dodged a bullet, didn't I? Without any symptoms it's the silent killer. I had no symptoms.
"I'm bloody lucky. If they hadn't been doing the trial I wouldn't have known," said Mr Wray, a 66-year-old electrical engineer from Takapuna.
Bowel cancer can at first have no obvious signs in some people, although others experience symptoms such as abdominal pain, changed bowel habit or bleeding.
Mr Wray agreed to join the programme after his GP mentioned it in January 2012. The following month, he received a home testing kit from the Waitemata District Health Board, which sat unused on a table for a fortnight.
Eventually he used the kit, the key part of which is a small scraper attached to the inside of a lid. A tiny sample of faeces is collected, secured inside the sample tube, which is sealed into a ziplock bag. The sample and signed consent form are posted to the DHB.
The day after Mr Wray posted the test kit, his GP rang to say the result was positive.
So began Mr Wray's journey of cancer diagnosis and treatment.
He had a colonoscopy - an investigation of the large intestine with a tube containing tiny instruments and a camera - at Waitakere Hospital in April 2012, which the surgeon told him found there was "a bit of a problem".
Surgery followed in May, when a 7cm length of the descending colon, containing the tumour, was removed.
Although there was no evidence of cancer having spread to outside the bowel, a cancer specialist told Mr Wray this was considered "borderline", so he took a 24-week course of chemotherapy to be on the safe side.
He had a colonoscopy last August "and I was all clear". He will have these checks every three years.
"I think the Government is a bit slow on the uptake on this," Mr Wray said. "By Saturday, 100 people will have died this month of bowel cancer; 1200 die a year. If 1200 people died on the roads, wouldn't they have a public safety campaign."
To men, he says: get checked. "It could save your life."
Possible bowel cancer symptoms:
Early bowel cancer often has no symptoms. If you experience any of the following for more than four to six weeks, tell your doctor:
* Bleeding from your bottom or blood in your bowel motion
* Going to the toilet more often, diarrhoea, constipation or feeling that your bowel does not empty completely
* Stomach pain, frequent wind pains, bloating or cramps
Source: Cancer Society