Early detection is a good way to boost your odds against bowel cancer but New Zealand's short supply of diagnostic firepower may be frustrating Kiwis' efforts to help themselves.
For a decade, shortages of colonoscopy have been cited as a reason for not creating the kind of national screening programme shown overseas to reduce bowel cancer death rates by 15 per cent.
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Health ministers have taken cautious steps and now the Government hopes to make a decision on a programme by year's end. But years of baby steps can be expected - in a country that has among the highest rates of bowel cancer incidence and death in the developed world.
Steps to a national programme
The Health Ministry's clinical director for bowel cancer, Dr Susan Parry, said that following a Government decision to establish a national screening programme it would take "at least two years to begin a full national roll-out, possibly starting with a limited age range, although we haven't agreed what that age range would be".
Officials fear overwhelming the fragile colonoscopy service with the thousands of extra referrals that will result from national screening. The risk is that adding people with a positive test result but no symptoms will blow out colonoscopy waiting times for those with symptoms.
Bowel screening mostly involves taking a tiny fecal sample at home, which the lab tests for invisible blood. People with a positive result are referred for colonoscopy, a check of the large bowel with a flexible viewing tube through which tissue samples and some abnormalities can also be removed.
The ministry estimates a sudden increase of around 50 per cent in demand for colonoscopy would result from a national screening programme using the same parameters as the Waitemata District Health Board's screening programme, which began in 2012 as a potential forerunner to a national scheme.
The options to reduce this surge are to start screening in several but not all districts at the same time, as proposed by the Labour Party; to screen a smaller age range than in the final version of the scheme, as other countries have done; or to set a high threshold for test results to be judged positive for referral to colonoscopy.
All three measures would mean some cancers are not detected as early as they might have been.
Dr Parry said some countries that started screening with the same test as proposed for New Zealand "use higher thresholds that are adjusted to detect the most cancers that can be detected within the available colonoscopy resource at the time".
Shortage of colonoscopy
Since 2012, when the ministry rewrote the rules for access to colonoscopy, DHBs have received taxpayer top-ups of more than $11 million to do more bowel checks.
The new rules also sought to dampen demand for people outside Waitemata's acclaimed pilot scheme - New Zealand's only bowel screening programme - getting the initial screening test for themselves.
For $62, this simple self-help test available from pharmacies helps people - with their GP's support - know if they should consider colonoscopy. It is the same sort of test that is the entry point for people aged 50 to 74 in the pilot scheme.
The ministry rules state that use of the fecal test by people without bowel cancer symptoms is "not currently recommended" outside the pilot and "should not be encouraged".
Dr Russell Walmsley, president of the Society of Gastroenterologists, whose members are the main type of doctors to perform colonoscopies, said, "Doing [a fecal blood] test in people with no symptoms is basically doing unorganised, unresourced screening.
"The DHBs have no capacity for this. We are barely ... keeping up with patients who have symptoms."
Dr Parry said the ministry's discouragement of the screening test in people outside the pilot without symptoms was to avoid an unanticipated increase in colonoscopy demand.
"We want to ensure that patients have timely procedures, which we have been struggling to deliver, and we have now done a lot of work to try and improve timely delivery."
But she accepted it would be ethically difficult for a DHB doctor assessing colonoscopy referrals from GPs to turn away an asymptomatic non-Waitemata patient aged 50-74 with a positive screening result.
Bowel Cancer NZ chairwoman Mary Bradley said the charity had "heard anecdotally people being rejected with positive results", but she was not in contact with any.
"The Bowel Cancer NZ view is that it's extremely dangerous and unethical. With the screening kit it's picking people up very early, possibly before they have any symptoms.
"If you detect bowel cancer before there are any symptoms you have up to a 90 per cent chance of surviving it. If it's left not investigated ... you potentially could die from it."
Alison Van Wyk, of Green Cross Health, whose pharmacies sell the test kits, said she was very concerned by the ministry's opposition to testing outside the pilot, "particularly when there is a lack of a national bowel screening programme".
More than 700 of the test kits were sold last year of which 70 returned a positive result for blood in the stool, although Green Cross did not have any further data, such as access of patients to colonoscopies.
The Government has set targets for "faster cancer treatment" which are much shorter for most than the waiting times of 2007, when major colonoscopy delays were identified, but the system is still falling short. Ministry data indicates a shortfall of 6500 colonoscopies this year, from total demand for around 45,000.
The 20 DHBs are measured monthly. August's data shows four DHBs - Bay of Plenty, Waikato, South Canterbury and West Coast - fell short of the target that 75 per cent of patients waiting for "urgent" colonoscopy receive it within 14 days.
Waitemata, Counties Manukau, Northland, Bay of Plenty and Waikato were among the 10 to miss the target for "non-urgent" patients, which is 65 per cent within six weeks.
Bay of Plenty, Waikato and Counties Manukau were also among the eight to miss the "surveillance" target of 65 per cent within 12 weeks, which includes those who have had bowel cancer surgery.
The Government has announced plans for nurses to learn endoscopy (which includes colonoscopy) from next year, but critics say more gastroenterologists are needed too and regardless of whether the trainee is a nurse or a doctor, it will take three years to learn properly.
"The Government has known for five years, some would say nine years, that capacity was going to be a problem and they haven't dealt with it," said Ms Bradley.
"We need a serious investment into colonoscopy."
Why our rate is so high
In the latest figures, bowel cancer is, alongside prostate cancer, New Zealand's third most commonly registered cancer, with 3016 cases in 2012. And with 1283 deaths, it is the second most common cause of cancer death.
New Zealand's bowel cancer death rate from 2000 to 2007 was higher than Australia's - 35 per cent higher for women and 24 per cent higher for men - according to a study last year.
Cancer specialist Dr Christopher Jackson, of Otago University, said the reasons for the disparity were unclear but probably included greater awareness of bowel cancer in Australia, its screening programme, timely access to surgery and greater access to state-funded medications.
"Survival is driven by a number of factors including stage at detection ... We showed [New Zealanders] are being picked up at a later stage, therefore there is a lot of work to do at the diagnosis end of the spectrum," he said, referring to the "Piper" study he led with the University of Auckland's Professor Michael Findlay to investigate colorectal cancer management.
Its major finding was that 24 per cent of colon cancer patients are diagnosed in New Zealand with stage 4 disease - meaning tumours have spread to distant organs and giving a five-year survival rate of less than 10 per cent.
In Australia 19 per cent are diagnosed with this stage; the UK is lower again at 17 per cent. New Zealand's rates were higher for Maori at 32 per cent and Pasifika, 35 per cent.
Another disparity highlighted in the study is that 34 per cent of New Zealand colon cancer patients sought their first medical help at a hospital emergency department, compared with 21 per cent in the UK.
"Presentation to hospital care through the ED rather than outpatient referral may suggest barriers to or within primary care," Piper's authors say.
In the first screening round of the Waitemata pilot, nearly 39 per cent of those with cancer had the disease in its earliest stage, compared with 12 cent in Piper who were stage 1.
"It shows screening detects cases [much earlier]," said Dr Jackson.
"Survival rates at stage 1 are massively higher than at stage 3 and 4. I think the screening pilot is doing a fantastic job. It is picking up a lot of early stage cancers and pre-malignant cancers which if left untreated will progress."
Australia started pilot screening programmes in 1999, progressed to a national programme for some age groups in 2006 and expects to have two-yearly screening for all 50-74-year-olds by 2020.
Former Cancer Society of Australia chief executive Professor Ian Olver said although uptake was still low - 36 per cent of those sent a screening kit - the early results were positive. Those diagnosed with cancer through the programme had nearly triple the rate of early-stage disease compared with those not diagnosed until they developed symptoms.
"We have a cost-effective programme which is far cheaper than treating widespread bowel cancer, can prevent cancer if polyps are diagnosed and treated before they become cancer or at least detect early cancer when it is still curable."
He cited a study which estimated the programme would cost A$38,217 ($41,821) for every year of life gained by people saved from bowel cancer death - when compared with no screening. This could improve to A$23,395 with full participation in
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