Bowel screening information should tell people how to get their actual reading, Bowel Cancer New Zealand says.
Results from the programme's initial test, the faecal immunochemical test (FIT), are routinely reported as positive or negative with participants and their family doctors not advised if traces of blood are found below the 200 ng haemoglobin/ml buffer solution threshold which would trigger referral to colonoscopy.
Participants can seek this information from the laboratory through their GP, but no process for doing this has been established and participants are not told anything about this.
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The panel which conducted the independent assurance review of the national bowel-screening programme recommends this issue should be further considered in consultation with primary health care providers.
The panel noted it may be of benefit for GPs to receive the detailed results so they could support appropriate management of those showing up with symptoms.
An interviewee was quoted in the panel's report as saying '' it would be very useful to know if someone's level was 12 versus 180 … just in terms of if they've then presented with symptoms''
BCNZ spokesperson Prof Sarah Derrett said the organisation wants the numerical information to go automatically to GPs.
''We would like to see GPs getting this reading as a matter of course, which they currently do not, as it will allow them to better monitor their patient should they present with further symptoms."
Federation of National Women's Health Councils co-convener Barbara Robson said the report from the independent panel clearly stated a lower number of cancers would be detected in the national programme, with its significant increase to the threshold before referral to colonoscopy and the restricted age range, compared with the pilot.
"This is the reality and it needs to be understood.''
Given this understanding, the Federation maintained it was essential participants were well informed about the bowel screening programme and the communication of FIT results.
The Federation has argued that participants and their GPs should be routinely informed of the FIT result and the actual numerical result of blood in the sample to better understand their results.
"While the NBSP has taken a step in the right direction and indicated it will provide numerical results to participants on request, it is pleasing to see the review panel recognises it may be of benefit for GPs to receive the detailed results too.''
It may be that most national screening participants are unaware the microscopic amount of blood in their faeces which would trigger a referral to colonoscopy is more than double that of the Waitemata pilot.
The reporting issue emerged In 2015 when the National Screening Advisory Committee raised '' substantial'' concerns about plans not to report full initial faecal blood results to general practitioners, given the change in the test threshold in the national programme.
It wanted the actual measurement provided so the GP could discuss what this may mean with a patient, creating the opportunity for future action, such as being alert to or acting on symptoms.
It was concerned then that without the numerical result there would be a group of people with a known elevated risk but the GP and the patient unaware of this.
However, in April last year the committee accepted Ministry arguments against this and backed off, saying demand for colonoscopies could put the national programme at risk if participants were given their full test results.
Among the arguments the Ministry put forward were that it would depart from accepted international practice, it could be misleading and could add to anxiety.
What are Faecal Immunochemical Test (FIT) thresholds?
Programme participants are referred for colonoscopy if traces of blood in their initial poo test reach a set threshold.
National bowel screening programme threshold: 200 ng haemoglobin/ml buffer solution
Waitemata pilot programme: 75ng Hb/ml buffer – those already in the pilot have now moved to the national programme, using the less sensitive threshold.
- ng = A nanogram which is equal to one billionth of a gram
Possible symptoms of bowel cancer
• Bleeding from the bottom or seeing blood in the toilet after a bowel motion;
• Change of bowel motions over several weeks without returning to normal;
• Persistent or periodic severe pain in the abdomen;
• A lump or mass in the abdomen;
• Tiredness and loss of weight for no particular reason;
Waitemata Bowel Screening Pilot Provisional Interval Cancer Data
Negative Faecal Immunochemical Test (FIT) cancers
• 56 cancers found between screenings in the three years to the end of 2014 after initial FIT tests were negative
• 18 of these cancers confined to the bowel when diagnosed
• 5 extended to nearby tissue
• 14 spread to lymph nodes
• 9 spread to distant organs
• The stage of 10 cancers at diagnosis not known
• 42 interval cancers found in people aged 60 -74 years when diagnosed
• 7 found in those aged 50-59
• 7 found in those aged 75 and above
"Normal'' Colonoscopy Cancers
• 10 found between screenings in those who had a '' normal'' colonoscopy in the years 2012 to 2015
• 3 extended to nearby tissue when diagnosed
• 3 spread to lymph nodes
• 2 spread to distant organs
• The stage of 2 cancers at diagnosis not known
• 2 found in those aged 50-59
• 6 found in those 60-74
• 2 found in those aged 75 and above