Appendix2 – Key similarities and differences between tests

Non-laxative CTC / Full-laxative CTC / Flexible sigmoidoscopy / Colonoscopy
Benefits
Aims / . Aims to detect pre-cancerous polyps, which can be removed to prevent cancer
. Aims to detect cancer at an early stage when it is more treatable
. Aims to detect serious disease (such as cancer) in organs outside the bowel, which may allow more effective treatment but this is not known for sure / . Aims to detect pre-cancerous polyps, which can be removed to prevent cancer
. Aims to detect cancer at an early stage when it is more treatable
. Aims to detect serious disease (such as cancer) in organs outside the bowel, which may allow more effective treatment but this is not known for sure / . Aims to detect pre-cancerous polyps, which can be removed to prevent cancer
. Aims to detect cancer at an early stage when it is more treatable / . Aims to detect pre-cancerous polyps, which can be removed to prevent cancer
. Aims to detect cancer at an early stage when it is more treatable
Incidence and mortality reduction / . Estimated to reduce the risk of getting bowel cancer by at least 23% and dying from bowel cancer by at least 31% / . Estimated to reduce the risk of getting bowel cancer by at least 23% and dying from bowel cancer by at least 31% / . Estimated to reduce the risk of getting bowel cancer by 23% and dying from bowel cancer by 31% / . Estimated to reduce the risk of getting bowel cancer by at least 23% and dying from bowel cancer by at least 31%
Practicalities
Test frequency and eligible age / . A one-off test at 55 years / . A one-off test at 55 years / . A one-off test at 55 years / . A one-off test at 55 years
Overview / . Scans the full length of the large bowel for polyps and cancers
. Scans organs outside the bowel in the abdomen for illnesses that may require treatment (most do not)
. The results are not always a definitive answer but will determine whether a follow-up investigation is needed / . Scans the full length of the large bowel for polyps and cancers
. Scans organs outside the bowel in the abdomen for illnesses that may require treatment (most do not)
. The results are not always a definitive answer but will determine whether a follow-up investigation is needed / . Looks inside the lower part of the large bowel for polyps or cancers
. The test can remove polyps and take samples of cancer
. The results may mean that a colonoscopy is needed for further investigation / . Looks inside the full length of the large bowel for polyps or cancers
. The test can remove polyps and take samples of cancer
Preparation and procedure / . A preparation would need to be drunk and dietary restrictions followed at home to colour stoolsbefore the test
. The test would be carried out in hospital by a specialist
. A person would be given a muscle relaxant and a thin tube would be passed into the large bowel to insert some air that may cause bloating during and after the test
. Two X-rays would be taken / . A powerful laxative preparation would need to be drunk (causing diarrhoea) and dietary restrictions followed at home to clean out the bowel before the test
. The test would be carried out in hospital by a specialist
. A person would be given a muscle relaxant and a thin tube would be passed into the large bowel to insert some airthat may cause bloating during and after the test
. Two X-rays would be taken / . An enema would need to be used at home (causing loose stools) to clean out the bowel before the test
. The test would be carried out in hospital by a specialist
. A thin, flexible tube with a camera on the end would be passed through the large bowel to look for polyps or cancers / . A powerful laxative preparation would need to be drunk (causing diarrhoea) and dietary restrictions followed at home to clean out the bowel before the test
. The test would be carried out in hospital by a specialist
. A person would be given a muscle relaxant, painkiller and sedative that would make a person drowsy with effects lasting up to 24 hours after the test
. A thin, flexible tube with a camera on the end would be passed through the large bowel to look for polyps or cancers
Duration / 20-30 minutes / 20-30 minutes / 30-45 minutes
Side-effects and complications
Risks / . Not being able to see all of the large bowel, which may require another test
. Perforation in one in 3,000 tests, which may require an operation
. Radiation-induced cancer in one in 1,700 tests, which may require further treatment or an operation / . Not being able to see all of the large bowel, which may require another test
. Perforation in one in 3,000 tests, which may require an operation
. Radiation-induced cancer in one in 1,700 tests, which may require further treatment or an operation / . Not being able to see all of the large bowel, which may require another test
. Perforation in one in 40,000 tests, which may require an operation
. Heavy bleeding in one in 3,300 tests, which may require further investigation or medical advice / . Not being able to see all of the large bowel, which may require another test
. Perforation in one in 1,500 tests, which may require an operation
. Heavy bleeding in one in 150 tests, which may require further investigation or medical advice
. Breathing or heart problems if people have a reaction to the sedative (rare)
. Death in extremely rare cases (one in 10,000)
Outcomes
Results delivery / . Within two weeks of the test / . Within two weeks of the test / . Immediately after the test; biopsy results within three weeks / . Immediately after the test; biopsy results within three weeks
Results of the screening test / . A normal result in 805 in 1,000 people who would not need any further tests
. One or more suspected polyps in 190 in 1,000 people. Half (90 in 180) would be recommended to have a colonoscopy. The other half would be offered another scan in 1-3 years
. A suspected cancer in 5 in 1,000 people who would be referred for treatment but may have a colonoscopy first
. An abnormality in an organ outside the large bowel in 20 in 1,000 people who may be offered a scan or a biopsy for further assessment / . A normal result in 815 in 1,000 people who would not need any further tests
. One or more suspected polyps in 180 in 1,000 people. Half (90 in 180) would be recommended to have a colonoscopy. The other half would be offered another scan in 1-3 years
. A suspected cancer in 5 in 1,000 people who would be referred for treatment but may have a colonoscopy first
. An abnormality in an organ outside the large bowel in 20 in 1,000 people who may be offered a scan or a biopsy for further assessment / . A normal result in 877 in 1,000 people who would not need any further tests
. One or more polyps found in 120 in 1,000 people. If a polyp is removed, a person would be told whether they are in a low, intermediate or high risk group. People in the high risk group (50 in 1,000 people) would be offered a colonoscopy
. A cancer found in 3 in 1,000 people who would be referred for treatment but may have a colonoscopy first / . A normal result in 675 in 1,000 people who would not need any further tests
. One or more polyps found in 320 in 1,000 people. If a polyp is removed, a person would be told whether they are in a low, intermediate or high risk group. People in intermediate or high risk groups would be offered a colonoscopy every one or three years
. A cancer found in 5 in 1,000 people who would be referred for treatment but may have a colonoscopy first
Sensitivity for cancers and polyps / . Over 85% accurate for detecting polyps or bowel cancer but there is a chance that a polyp or cancer could be missed / . Over 90% accurate for detecting polyps or bowel cancer but there is a chance that a polyp or cancer could be missed / . Over 65% accurate for detecting polyps or bowel cancer but there is a chance that a polyp or cancer could be missed / . Over 90% accurate for detecting polyps or bowel cancer but there is a chance that a polyp or cancer could be missed
Results of any follow-up tests / . 50 in 100 people who have a follow-up colonoscopy would have a normal result
. 44 in 100 people would have a polyp and removal may prevent cancer
. 6 in 100 people would be found to have cancer and be referred for treatment. 90% of bowel cancers can be cured if found in the early stages
. Risks of colonoscopy consist of heavy bleeding (1 in 150), perforation (1 in 1,500) and death (1 in 10,000) / . 45 in 100 people who have a follow-up colonoscopy would have a normal result
. 49 in 100 people would have a polyp and removal may prevent cancer
. 6 in 100 people would be found to have cancer and be referred for treatment. 90% of bowel cancers can be cured if found in the early stages
. Risks of colonoscopy consist of heavy bleeding (1 in 150), perforation (1 in 1,500) and death (1 in 10,000) / . 810 in 1,000 people who have a follow-up colonoscopy would have a normal result
. 186 in 1,000 people would have a polyp and removal may prevent cancer
. 4 in 1,000 people would be found to have cancer and be referred for treatment. 90% of bowel cancers can be cured if found in the early stages
. Risks of colonoscopy consist of heavy bleeding (1 in 150), perforation (1 in 1,500) and death (1 in 10,000) / . No follow-up investigations apply