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| The big screen |
2-Aug-2006 |
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From this month, about one million parcels will be sent to a selection of Australians aged over 55. The enclosed test kits could save their lives.
By Bianca Nogrady.
AUSTRALIAN women are used to screening programs — they have undergone regular mammograms and cervical smears for decades. However, the roll-out of an FOBT-based screening program for colorectal cancer marks the first time healthy Australian men will be subjected to a population-based cancer screening procedure.
Not that many will be complaining. Colorectal cancer is now the number one cause of cancer-related deaths in Australia and, thanks to diet and lifestyle, this country has one of the highest incidences in the world. Each year, about 12,600 new cases are diagnosed and 4700 Australians die from the disease.
Studies, including the Australian pilots for the screening program, suggest screening with FOBT could reduce bowel cancer mortality by up to 33% — which is why experts have been pushing for such a program for a decade or more.
Professor Finlay Macrae, head of colorectal medicine and genetics at RoyalMelbourneHospital, is happy the initial phase of the program is finally going ahead, although he questions why it has taken so long. “Level one evidence for mortality reduction from FOBT was available 10 years ago,” he says. “It is a great credit to the Federal Government that they have initiated this program, albeit rather late and with a cost of 1000-2000 Australian lives for each year of that delay.”
The choice of FOBT as the screening tool was based on a large body of high-quality evidence on its use, although some experts initially expressed a preference for a 10-yearly colonoscopy-based screening program. Colonoscopy is the most sensitive and specific means of testing for bowel cancer, but it is also considerably more expensive, more invasive and associated with risks such as perforation of the colon. What’s more, there haven’t been any randomised controlled trials using colonoscopy or sigmoidoscopy in population screening for bowel cancer, Professor Macrae says. For FOBT screening, on the other hand, numerous randomised controlled trials and meta-analyses have found a significant benefit in reduced mortality.1
The type of FOBT selected for the Australian program — the immunochemical Detect test — has also been controversial.
A recent Australian study found the cheaper guaiac test had a higher positive predictive value than the immunochemical test, with researchers arguing this could reduce the number of false positives and unnecessary colonoscopies.2
However, the guaiac test requires patients to modify their diet for three days before taking the test, and the sampling method is more complicated.
The immunochemical FOBTs were chosen because they were less intrusive, more reliable, more acceptable and more likely to achieve higher participation rates, according to an evaluation of the Australian pilots.
The logistics of rolling out a national screening program of this size are immense.
From this month, Australians who turn 55 or 65 between 1 May 2006 and 30 June 2008, as well as those who participated in the pilot studies, will be sent an FOBT kit. It has been a long time coming for the pilot participants, who were originally promised a second round of screening after two years, but have had to wait four.
Participants will also be encouraged to nominate a GP to receive the results of the test — whether positive or negative. Patient details, including name, address, age, gender, Medicare number, screening history and nominated GP will be kept in a national bowel cancer screening register administered by Medicare Australia.
If the three-state pilot studies are anything to go by, at least half of those sent a test kit will return it, raising hopes the program will significantly reduce bowel cancer mortality.
“We know that if someone actually does the screening test, they will reduce their chance of dying from bowel cancer by at least 40%,” says Professor Graeme Young, professor of gastroenterology at Flinders University in Adelaide and a member of the executive committee for the pilot studies. If even half the eligible people participate, bowel cancer mortality could be reduced by at least 25% over 10 years, he says.
Patients whose tests are positive will be advised by letter to consult their GP, who will also be informed of the result. All patients with a positive FOBT should be referred for diagnostic evaluation of the colon, even if the GP suspects another cause, such as haemorrhoids, Professor Young says.
“If there is a positive FOBT, there is a 5-10% risk that cancer is present. If they don’t [refer] and the patient turns out to have a cancer then they will clearly be liable.”
The issue of GP liability and duty of care was highlighted in the pilot studies. When patients in the pilots were required to nominate a GP, some named a doctor they had never seen. Dr Mary Belfrage, a GP co-ordinator for the Melbourne pilot, says this caused considerable concern among doctors.
“If it’s a patient that’s known to that GP, it’s probably not really an issue because they’re going to have a way of tracking that person,” Dr Belfrage says. “[But] if a GP receives a letter about someone they don’t even know, have they inherited duty of care?”
In response to these concerns, the national program advises patients to nominate a GP when they return the test kits, but it is not an absolute requirement.
The Federal Health Department says GPs can be reassured the program does not place any additional legal duty on them beyond the normal duty of care to a patient.
“In this context, the legal advice recommends that a GP follow up a person with a positive FOBT result once by telephone and/or once in writing to encourage them to make an appointment either with them or another provider,” the health department says. “The participant should be followed up again if they do not attend the appointment.” Alternatively, GPs can notify the register that they do not intend to follow up the participant so the register can take on this responsibility.
To help the register keep track of follow-up, GPs will be asked to complete a notification form when consulted by a patient with a positive result, in return for an information payment of $6.60.
The pilot studies recorded unexpectedly low follow-up rates, with only two-thirds of patients who had a positive FOBT being registered as having visited their GP. However, most experts believe this was due to incomplete data collection rather than lack of follow-up.
In a bid to improve data collection, the health department has appointed data managers in each state and territory to follow up participants who have not recorded a GP visit or attended for colonoscopy. Medicare data may be used to check whether patients have accessed colonoscopy services.
However, $6.60 is not much of an incentive for busy doctors to fill out the follow-up form and return it, Professor Young argues. He believes the government should also have taken responsibility for funding and monitoring the colonoscopy part of screening to prevent the usual assortment of complications associated with the federal/state health divide.
“Because the government is not funding the colonoscopy process, it doesn’t therefore have control of the data return,” he says.
Instead, states and territories are charged with ensuring colonoscopies are available for participants who return a positive result.
They’ll have their work cut out achieving this. A major issue highlighted by the pilot evaluation was the waiting time for follow-up colono-scopy due to the sudden increase in workload. One site reported an additional 20 patients a week referred from the pilot. Overall, patients waited an average of 38.5 days for a colonoscopy, a delay that caused significant anxiety, Dr Belfrage says.
“Once you’ve generated in people’s mind the possibility of it being a serious health issue, you have to be able to respond to it and resolve it in a reasonable time frame because otherwise you’re generating morbidity,” she says.
“It’s really important for those who have a positive test that they’ve got access to timely colonoscopy, that they’re not left waiting a long time for the next step.”
Part of the problem is that colonoscopies are too often used inappropriately, she says. “Currently, there are a lot of colonoscopies being done that [don’t] meet the clinical indications.”
The health department says it will be mapping capacity during this first phase to help build necessary infrastructure and workforce to meet the colonoscopy demands of a “mature” screening program down the track.
But Professor Macrae believes state and territory governments could be doing more now. He would like to see hospital managements come under pressure to reduce colonoscopy waiting lists in the way they have in relation to other surgical waiting lists.
Although some issues remain to be ironed out, the new screening program attracts overwhelming support, with Professor Young calling it “one of the fundamental historic events in Australian medicine”.
Professor Jim Bishop, head of the Cancer Institute of NSW, which is assisting with the program in NSW, says teething problems are to be expected.
“I think we just have to be a little bit tolerant because the basic premise of screening is good,” he says.
“We anticipate that the same thing will probably happen as happened with the breast cancer screening roll-out, that it took a couple of years to establish the program.”
The government sees this first phase as the test run for a full-scale national program, likely to see FOBT screening offered every two years to all Australians aged 55-74.
Professor Bishop is reasonably confident such a program will eventually be launched. “It seems to me it’s quite likely it would be fully rolled out over time, just because of the rationale backing it up, which is very solid.”
Professor Young is even more certain the program has passed the point of no return. Not only is it as cost-effective as breast or cervical cancer screening, but “we already know that at least 50% of the population will do the test, and that’s people voting with their feet”, he says.
BOWEL SCREENING: THE PROGRAM AT A GLANCE
* The first wave of Australia’s national bowel cancer screening program will be rolled out
between August 2006 and June 2008.
* FOBT kits will be sent to all Australians who turn 55 or 65 between 1 May 2006 and 30
June 2008, as well as to participants in the earlier pilot studies.
* Participants will be given detailed instructions on how to use the test kits and a pre-paid
envelope for return of the completed kits. They will also be asked, but not obliged, to
nominate a GP.
* Results will be sent to the patient and their GP, if nominated. If the result is positive,
patients will be instructed to consult their GP for follow-up.
* If no follow-up visit is recorded with the screening register, it will continue to send reminder
letters to the patient and their GP until a visit is recorded or the patient becomes
uncontactable.
* An information kit is being prepared for GPs ahead of the roll-out.
* A future national program could screen all Australians aged 55-74 every two years.
ABOUT FOBT
A FAECAL occult blood test detects microscopic blood that may have been released from a bowel cancer or precursors such as polyps or adenomas.
Under ideal conditions, an FOBT may detect 80-90% of cancers and 60-75% of large adenomas. In screening programs, a person with a positive FOBT result has a 30-45% chance of having an adenoma and a 3-5% chance of colorectal cancer.
The FOBT kits used in the Australian program do not require any special dietary preparation.
Source: www.cancerscreening.gov.au/bowel/pubs/pubs_prof.htm
References
1. Medical Journal of Australia 2005; 182:52-53.
2. Australian Doctor, 12 May 2006, page 3.
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