Modelled evaluation of alternative screening technologies

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Background

The literature review found high-level evidence supporting effectiveness (mortality reduction) of immunochemical faecal occult blood testing (iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin.) and flexible sigmoidoscopy in population screening for colorectal cancer, compared with no screening. However, there was no high-level evidence evaluating colonoscopy, computed tomography (CT) colonography, or cancer-specific faecal or blood biomarkers.

Future large-scale trials to further evaluate screening strategies are unlikely, due to the cost and necessary duration. When RCTA study in which people are allocated at random (by chance alone) to receive one of several clinical interventions. One of these interventions is the standard of comparison or control. evidence cannot be obtained, modelling studies based on sophisticated understanding of colorectal cancer natural history are an acceptable source of data to guide public health planning decisions.[1][2][3][4][5]

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Modelling study findings

In persons without a colorectal cancer diagnosis or symptoms that might indicate colorectal cancer, what is the most cost-effective, feasible and acceptable screening modality (iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin., flexible sigmoidoscopy, colonoscopy, CT colonographyAlso known as virtual colonoscopy, a medical imaging procedure that uses low dose radiation CT scanning to obtain an interior view of the colon (the large bowel) that is otherwise only seen with a more invasive procedure where an endoscope is inserted into the rectum and passed through the entire colon., faecal or blood biomarkers test, or any combinations) compared with no screening? (PSC1c)

A comprehensive validated model of colorectal cancer development and bowel screening (‘Policy1-Bowel’) was used to simulate the National Bowel Cancer Screening ProgramAn Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease.) and alternative screening approaches (Table 3.3). Details of the methods and result can be found in the Technical Report.

The term ‘adherence’ applies to compliance with recommendations for screening, follow-up and surveillance.

The strategies were evaluated in context of three scenarios:

  • Scenario 1 assumes perfect adherence to screening, follow-up and surveillance recommendations.
  • Scenario 2 assumes high (but imperfect) participation (participation after first invitation was 57% for screening strategies using iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. and faecal/ blood biomarkers test, and was 35% for screening strategies using colonoscopy, sigmoidoscopy and CT colonographyAlso known as virtual colonoscopy, a medical imaging procedure that uses low dose radiation CT scanning to obtain an interior view of the colon (the large bowel) that is otherwise only seen with a more invasive procedure where an endoscope is inserted into the rectum and passed through the entire colon.).
  • Scenario 3 assumes lower participation (participation after first invitation was 27% for screening strategies using iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. and faecal/ blood biomarkers test, and was 15% for screening strategies using colonoscopy, sigmoidoscopy and CT colonographyAlso known as virtual colonoscopy, a medical imaging procedure that uses low dose radiation CT scanning to obtain an interior view of the colon (the large bowel) that is otherwise only seen with a more invasive procedure where an endoscope is inserted into the rectum and passed through the entire colon.).

Specific participation assumptions differed according to screening modality and an individual's screening history and were derived based on currently observed screening participation in Australia and expert opinion for new modalities (see Appendix for details of participation assumptions for each modality).

Table 3.3 ScreeningPerforming tests to identify disease in people before any symptoms appear. strategies evaluated
Strategy name Description
No screening (comparator) No screening
iFOBT2y iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020)
iFOBT1y iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every year at age 50–74 years
plasmaDNA2y (exploratory modelling based on limited data from a small number of cross-sectional studies; no data on longitudinal outcomes for this technology available) pDNA screening every 2 years at 50–74 years (pDNA assuming test for methylated SEPT9 DNA, as reported in Church et al 2014).[6]
fDNA2y (exploratory modelling based on limited data from a small number of cross-sectional studies; no data on longitudinal outcomes for this technology available) fDNA screening every 2 years at age 50–74 years (multi-target faecal testing including iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin., assuming test characteristics reported in Imperiale et al (2014).[7]
fDNA5y (exploratory modelling based on limited data from a small number of cross-sectional studies; no data on longitudinal outcomes for this technology available) fDNA screening every 5 years at age 50–74 years
COL10y COL screening every 10 years at ages 55, 65 and 75 years
SIG10y SIG screening every 10 years at ages 55, 65 and 75 years
CTC10y (exploratory modelling based on limited data from a small number of cross-sectional studies; no data on longitudinal outcomes for this technology available) CTC screening every 10 years at ages 55, 65 and 75 years
SIG@60 Once-off SIG screening at age 60 years
SIG@55_iFOBT2y @60To74 Once-off SIG screening at age 55 years combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years at age 60–74 years
COL@50_iFOBT2y @52To74 Once-off COL screening at age 50 years combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years at age 52–74 years^
iFOBT2y+SIG@50 iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020) combined with SIG at age 50 years for negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin.
iFOBT2y+SIG@54_64_74 iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020) combined with SIG at ages 54, 64 and 74 years for negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin.
iFOBT2y+plasmaDNA iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020) combined with pDNA testing in under-screened individuals^^
COL: colonoscopy; CTC: computed tomographic colonography; iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin.: immunochemical faecal occult blood test; fDNA: faecal DNA test; pDNA: plasma DNA test; SIG: flexible sigmoidoscopy
Notes:
^: Individuals aged 50 years who do not participate in colonoscopy screening will be invited to have an iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin..
^^: Under-screened individuals are those who are not under colonoscopy surveillance and have not had an iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. test in the past 4 years (including those who are eligible for screening but have never have a screening test).
No leakage (drop in participation) from main program is assumed after pDNA is offered (a favourable scenario).

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Health outcomes (benefits)

Perfect adherence

When assuming perfect adherence to screening, follow-up and surveillance recommendations (Scenario 1), colorectal cancer screening was predicted to reduce age-standardised risk (in 0-89 years) of colorectal cancer incidence by 23–67% and colorectal cancer mortality by 30–82% (encompassing a range of results, depending on screening technology and screening interval and age range), compared to no screening.

For seven screening strategies, a reduction in age-standardised colorectal cancer mortality risk (in 0-89 years) of greater than 75% was predicted in perfectly adherent cohorts. These strategies were:

  • faecal DNA test (fDNA) screening every 2 years at age 50–74 years (82% reduction)
  • colonoscopy screening every 10 years at age 55, 65 and 75 years (77% reduction)
  • once-only colonoscopy screening at age 50 years combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 52–74 years (80% reduction)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every year at age 50–74 years (81% reduction)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (75% reduction)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years , with adjunctive flexible sigmoidoscopy at age 50 years for individuals with negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. results (77% reduction)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years, with adjunctive flexible sigmoidoscopy screening at age 54, 64 and 74 years for individuals with negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. (79% reduction).

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Imperfect adherence

After accounting for realistic adherence to screening, follow-up and surveillance recommendations:

  • When assuming high participation (Scenario 2), colorectal cancer screening was predicted to reduce age-standardised risk (in 0-89 years) of colorectal cancer incidence by 6–48% and colorectal cancer mortality by 7–69%, compared to no screening.
  • When assuming low participation (Scenario 3), colorectal cancer screening was predicted to reduce age-standardised risk (in 0-89 years) of colorectal cancer incidence by 3–38% and colorectal cancer mortality by 3–56%, compared to no screening.

Seven strategies predicted a greater than 50% mortality reduction in Scenario 2 (high participation) and greater than 35% reduction in Scenario 3 (low participation):

  • fDNA screening every 2 years (63% in Scenario 2; 44% in Scenario 3)
  • once-off colonoscopy screening at age 50 years combined with 2-yearly iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening at 52–74 years (57% in Scenario 2; 40% in Scenario 3)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every year at age 50–74 years (69% in Scenario 2; 56% in Scenario 3)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (53% in Scenario 2; 36% in Scenario 3)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years, with adjunctive flexible sigmoidoscopy screening at age 50 years for individuals with negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. (53% in Scenario 2; 37% in Scenario 3)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years, with adjunctive flexible sigmoidoscopy screening at age 54, 64 and 74 years for individuals with negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. (55% in Scenario 2; 37% in Scenario 3)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years, with plasma DNA testing (pDNA) for under-screened individuals, assuming that the offer of pDNA does not induce any ‘leakage’ (participation drop) in iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening – a favourable assumption (54% in Scenario 2; 39% in Scenario 3).

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Cost-effectiveness

Of the strategies examined, only computed tomography colonography (CTC) screening every 10 years and iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years remained cost-effective in all screening participation scenarios considered, in context of an indicative willingness-to-pay threshold of A$50,000 per life–year saved in Australia. Of these two strategies, iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. was the most effective, with an incremental cost-effectiveness ratio of A$6,412–33,535 per life–year saved, compared with CTC screening every 10 years (depending on participation).

Therefore, the current NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. is the most effective strategy for colorectal cancer screening in Australia that is also cost-effective.

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Resource utilisation

Modelling was used to estimate the number of iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. test, pDNA tests, fDNA tests, colonoscopy, flexible sigmoidoscopy and CTC tests in the lifetime of 100,000 persons alive at 40 years for each strategy.

In all participation scenarios, colonoscopy screening every 10 years, once-off colonoscopy screening at age 50 years combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years, iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every year and fDNA screening every 2 years were predicted to lead to the highest number of colonoscopy procedures. ScreeningPerforming tests to identify disease in people before any symptoms appear. with once-off flexible sigmoidoscopy at 60 years, with sigmoidoscopy every 10 years, or with CTC screening every 10 years, were estimated to lead to the lowest number of colonoscopies.

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Balance of benefits to harms

In all participation scenarios, strategies assuming pDNA screening every 2 years, colonoscopy screening every 10 years, and once-off colonoscopy screening at age 50 years combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years, were estimated to be associated with the highest number-needed-to-colonoscope (NNC) per colorectal cancer case or colorectal cancer death prevented, compared with the other strategies (i.e. these strategies had the least favourable ratio of benefits to harms).

When compared with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years, five strategies were found to be associated with greater reductions in colorectal cancer deaths but also resulted in higher numbers of colonoscopies in all scenarios (details in Table 9.3):

  • fDNA screening every 2 years at age 50–74 years (fDNA2y)
  • Once-off COL screening at age 50 years, combined with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years at age 52–74 years (COL@50_iFOBT2y)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every year at age 50–74 (iFOBT1y)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020) combined with flexible sigmoidoscopy at age 50 for negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. (iFOBT2y+SIG@50)
  • iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. screening every 2 years at age 50–74 years (NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. from 2020) combined with SIG at 54, 64 and 74 years for negative iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. (iFOBT2y+SIG@54_64_74).

These five strategies were estimated to be associated with a higher NNC per colorectal cancer death prevented compared with iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years (278–1150 in Scenario 1, 106–381 in Scenario 2, and 65–190 in Scenario 3).

No strategy was predicted to result in both fewer colorectal cancer deaths and fewer colonoscopies than iFOBTA test that can detect microscopic amounts of blood in stools. Types of FOBT include immunochemical FOBTs (iFOBTs), which directly detect haemoglobin using antibodies specific for the globin moiety of human haemoglobin, and guaiac FOBTs (gFOBTs), which detect peroxidase activity, an indirect method for identification of haemoglobin. every 2 years. This finding implies that the strategy adopted in the current NBCSPThe National Bowel Cancer Screening Program. An Australian screening program that aims to reduce illness and death from bowel cancer through early detection or prevention of the disease. has an optimal balance of benefits and harms, given the strategies considered in this evaluation.

See the Evidence summary and recommendations section for guidance resulting from this modelling.

Next section: screening age

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References

  1. Cenin DR, St John DJ, Ledger MJ, Slevin T, Lansdorp-Vogelaar I. Optimising the expansion of the National Bowel Cancer Screening Program. The Medical Journal of Australia 2014;201:456-61 Abstract available at https://www.mja.com.au/journal/2014/201/8/optimising-expansion-national-bowel-cancer-screening-program.
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  6. Church TR, Wandell M, Lofton-Day C, Mongin SJ, Burger M, Payne SR, et al. Prospective evaluation of methylated SEPT9 in plasma for detection of asymptomatic colorectal cancer. Gut 2014 Feb;63(2):317-25 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/23408352.
  7. Imperiale TF, Ransohoff DF, Itzkowitz SH, Levin TR, Lavin P, Lidgard GPA medical professional who treats acute and chronic illnesses and provides preventive care and health education to a wide range of patients., et al. Multitarget stool DNA testing for colorectal-cancer screening. N Engl J Med 2014 Apr 3;370(14):1287-97 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/24645800.
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Appendices


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