Results of the first round of a demonstration pilot of screening for colorectal cancer in the United Kingdom
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《英国医生杂志》
Correspondence to: Professor R J C Steele, University Department of Surgery and Molecular Oncology, Ninewells Hospital, Dundee DD1 9SY r.j.c.steele@dundee.ac.uk
Abstract
Population based randomised trials are necessary to demonstrate the efficacy of a screening strategy.1 In colorectal cancer, guaiac based testing of faecal occult blood is the only screening modality that has been shown to reduce disease specific mortality by means of such trials. Studies of most relevance for the United Kingdom were those carried out in Nottingham, England, and in Funen, Denmark, which showed reductions in deaths from colorectal cancer of 15% and 18%, respectively, after screening.2 3
Although it is accepted that screening for faecal occult blood is efficacious, randomised trials are carried out by highly motivated research teams.4 On the advice of the National Screening Committee, the UK Department of Health carried out a demonstration pilot to test the feasibility of a national screening programme for colorectal cancer. We report on the uptake, outcomes, and consequences of the project.
Methods
Screening started on 29 March 2000 with the despatch of the first test kits. The prevalence (first) round was completed on 19 May 2003 with the last colonoscopy. The results presented here pertain to uptake, the rate of positive test results (positivity), colonoscopy, positive predictive value, and distribution of stage of cancer. Figure 1 details the flow of participants through the pilot.
Fig 1 Flow diagram of pilot
Uptake and positivity
Overall, 478 250 residents (England 185 267, Scotland 292 983) were invited to participate; testing was completed for 271 646 (56.8%). This uptake was higher for England than for Scotland (table 1), higher in women than in men, and increased with age (fig 2). Of 276 819 responders, 98.1% (n = 271 646) completed the test. The overall uptake (56.8%) was comparable to the Nottingham study (57% in the prevalence round).2
Table 1 Uptake and positivity rate in pilot screening for colorectal cancer compared with prevalence round of Nottingham trial. Values are numbers (percentages)
Fig 2 Variations in uptake of faecal occult blood test by age and sex
The overall positivity rate was 1.9% (England 1.6%, Scotland 2.1%; P < 0.001). Although the positivity rate in the Nottingham study was 2.1%, this trial embraced a wider age range (50-74) than the pilot; the rate was 1.8% for the 50-69 age range (J H Scholefield, personal communication, 2003).2 Thus, although the results for England were similar to those for Nottingham, the positivity rate for Scotland was higher (see table 1). Men had a higher rate than women, and positivity increased with age (fig 3).
Fig 3 Variations in positivity of faecal occult blood test by age and sex
Colonoscopy
Overall, 3700 of 4116 people had a complete colonoscopy (completion rate 89.9%). The uptake of colonoscopy among people with a positive test result was 81.5% (4116 of 5050), and only 76 (1.5%) were deemed medically unfit to undergo the examination. In total, 858 (16.9%) did not attend, but 172 (20%) of these were under follow up, 69 (8%) had undergone recent colonoscopy, 51 (6%) had opted for colonoscopy in a private clinic, and 17 (2%) had no colon.
Colonoscopy was accompanied by some morbidity. Ten patients (0.24%) were admitted for overnight observation because of bleeding or abdominal pain; 13 (0.32%) were readmitted for the same reasons. None required intervention. Two people had perforations (0.05%), one owing to the size of a polyp after polypectomy.
Positive predictive value
The positive predictive values of a positive test result were 10.9% for invasive cancer and 35.0% for adenoma. The values for cancer were higher for Scotland and in men. All values compared favourably to those of the Nottingham study in the 50-69 age range (table 2).
Table 2 Positive predictive values of colonoscopies conducted in screening pilot and Nottingham trial
Stage distribution of screen detected cancer
Overall, 552 cancers detected by screening were diagnosed, of which 92 (16.6%) were invasive polyp cancers, removed at colonoscopy. In the pilot, if polyp cancers with no information on staging (colectomy to remove residual disease after polypectomy not carried out) were classified as Dukes's stage A, then 265 (48%) of the screen detected cancers would be at stage A and five (1%) at stage D (with metastases; fig 4).
Fig 4 Dukes's stage of cancers detected by screening in pilot. "Polyp cancers" are defined as invasive cancers removed at colonoscopy when colectomy was not carried out
The proportions of screen detected cancers presenting at Dukes's stages A or B were similar for England and Scotland. Both were comparable to the Nottingham values at the first invitation to participate (table 3).
Table 3 Dukes's stage of colorectal cancer in pilot and in Nottingham trial at first invitation to participate. Values are numbers (percentages)
Neoplasia detection rates
The cancer detection rate for the pilot was 1.62 per 1000 people screened, and 6.91 for all neoplasia (cancers and adenomas). The cancer detection rate in England was comparable to the 50-69 age range in the prevalence round of the Nottingham trial whereas it was higher in Scotland (table 4). The overall detection rate for neoplasia was higher in Scotland than in England, particularly for men.
Table 4 Detection rates for cancer and neoplasia per 1000 people screened (faecal occult blood testing complete) for pilot and prevalence screen of Nottingham trial
Discussion
Hardcastle JD, Bennett DH, Whynes DK. Mass screening: European/UK perspective. In: Young GP, Rozen P, Levin B, eds. Prevention and early detection of colorectal cancer. London: WB Saunders, 1996: 275-88.
Hardcastle JD, Chamberlain JO, Robinson MHE, Moss SM, Amar SS, Balfour TW, et al. Randomised controlled trial of faecal occult blood screening for colorectal cancer. Lancet 1996;348: 1472-7.
Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecal occult blood test. Lancet 1996;348: 1467-71.
Fentiman I. Detection and treatment of early breast cancer. Philadelphia: Lippincott, 1990: 618.
Steele RJC, Parker R, Patnick J, Warner J, Fraser C, Mowat NA, et al. A demonstration pilot for colorectal cancer screening in the United Kingdom: a new concept in the introduction of health care strategies. J Med Screen 2001;8: 197-202.
Mandel JS, Bond JH, Church JR, Snover DC, Bradley GM, Schuman LM, et al. Reducing mortality from colorectal cancer by screening for faecal occult blood. N Engl J Med 1993;328: 1365-71.
De Koning HJ. Assessment of nationwide cancer-screening programmes. Lancet 2000;355: 80-1.
Gryd-Hansen D, Sogaard J, Kronborg O. Colorectal cancer screening: efficiency and effectiveness. Health Econ 1998;7: 9-20.
Thomas-Gibson S, Thapar C, Shah SG, Saunders BP. Colonoscopy at a combined district general hospital and specialized endoscopy unit: lessons from 505 consecutive examinations. J R Soc Med 2002;95: 194-7.
Department of Health. The NHS cancer plan: a plan for investment, a plan for reform. London: DoH, 2000.
Scottish Intercollegiate Guidelines Network. Management of colorectal cancer: a national clinical guideline. Edinburgh: SIGN. Mar 2003: 6. (Guideline No 67.)
Atkin WS, Saunders BP. Surveillance guidelines after removal of colorectal adenomatous polyps. Gut 2002;51(suppl v): v6-9.
Pathmakanthan S, Murray I, Smith K, Heeley R, Donnelly M. Nurse endoscopists in United Kingdom health care: a survey of prevalence, skills and attitudes. J Adv Nurs 2001;36: 705-10.
Pye G, Christie M, Chamberlain JO, Moss SM, Hardcastle JD. A comparison of methods for increasing compliance within a general practitioner based screening project for colorectal cancer and the effect on practitioner workload. J Epidemiol Community Health 1988;42: 66-71.
Muller AD, Sonnenberg A. Protection by endoscopy against death from colorectal cancer: a case-control study amongst veterans. Arch Intern Med 1995;155: 1741-8.
UK Flexible Sigmoidoscopy Screening Trial Investigators. Single flexible sigmoidoscopy screening to prevent colorectal cancer: baseline findings of a UK multicentre randomized trial. Lancet 2002;359: 1291-300.
Rasmussen M, Fenger C, Kronborg O. Diagnostic yield in a biennial Haemoccult-II screening programme compared to a once-only screening with flexible sigmoidoscopy and Haemoccult-II. Scand J Gastroenterol 2003;38: 114-8.
Department of Health Press Release 2003/0047 (www.info.doh.gov.uk/doh/intpress.nsf/page/2003-0047) (accessed Aug 2003).
Scottish Executive Health Department. Cancer in Scotland Action for Change Bowel Cancer Framework for Scotland. Edinburgh: SEHD, 2004.
Steele RJC, Gnauck R, Hrcka R, Kronborg O, Kuntz C, Moayyedi P, et al. Methods and economic considerations. Report from the ESGE/UEGF workshop on colorectal cancer screening. Endoscopy 2004;36: 349-53.
Tengs TO, Adams ME, Pliskin JS, Safran DG, Siegel JE, Weinstein MC, et al. Five hundred life-saving interventions and their cost-effectiveness. Risk Analysis 1995;15: 369-90.(, for the UK Colorectal C)
Abstract
Population based randomised trials are necessary to demonstrate the efficacy of a screening strategy.1 In colorectal cancer, guaiac based testing of faecal occult blood is the only screening modality that has been shown to reduce disease specific mortality by means of such trials. Studies of most relevance for the United Kingdom were those carried out in Nottingham, England, and in Funen, Denmark, which showed reductions in deaths from colorectal cancer of 15% and 18%, respectively, after screening.2 3
Although it is accepted that screening for faecal occult blood is efficacious, randomised trials are carried out by highly motivated research teams.4 On the advice of the National Screening Committee, the UK Department of Health carried out a demonstration pilot to test the feasibility of a national screening programme for colorectal cancer. We report on the uptake, outcomes, and consequences of the project.
Methods
Screening started on 29 March 2000 with the despatch of the first test kits. The prevalence (first) round was completed on 19 May 2003 with the last colonoscopy. The results presented here pertain to uptake, the rate of positive test results (positivity), colonoscopy, positive predictive value, and distribution of stage of cancer. Figure 1 details the flow of participants through the pilot.
Fig 1 Flow diagram of pilot
Uptake and positivity
Overall, 478 250 residents (England 185 267, Scotland 292 983) were invited to participate; testing was completed for 271 646 (56.8%). This uptake was higher for England than for Scotland (table 1), higher in women than in men, and increased with age (fig 2). Of 276 819 responders, 98.1% (n = 271 646) completed the test. The overall uptake (56.8%) was comparable to the Nottingham study (57% in the prevalence round).2
Table 1 Uptake and positivity rate in pilot screening for colorectal cancer compared with prevalence round of Nottingham trial. Values are numbers (percentages)
Fig 2 Variations in uptake of faecal occult blood test by age and sex
The overall positivity rate was 1.9% (England 1.6%, Scotland 2.1%; P < 0.001). Although the positivity rate in the Nottingham study was 2.1%, this trial embraced a wider age range (50-74) than the pilot; the rate was 1.8% for the 50-69 age range (J H Scholefield, personal communication, 2003).2 Thus, although the results for England were similar to those for Nottingham, the positivity rate for Scotland was higher (see table 1). Men had a higher rate than women, and positivity increased with age (fig 3).
Fig 3 Variations in positivity of faecal occult blood test by age and sex
Colonoscopy
Overall, 3700 of 4116 people had a complete colonoscopy (completion rate 89.9%). The uptake of colonoscopy among people with a positive test result was 81.5% (4116 of 5050), and only 76 (1.5%) were deemed medically unfit to undergo the examination. In total, 858 (16.9%) did not attend, but 172 (20%) of these were under follow up, 69 (8%) had undergone recent colonoscopy, 51 (6%) had opted for colonoscopy in a private clinic, and 17 (2%) had no colon.
Colonoscopy was accompanied by some morbidity. Ten patients (0.24%) were admitted for overnight observation because of bleeding or abdominal pain; 13 (0.32%) were readmitted for the same reasons. None required intervention. Two people had perforations (0.05%), one owing to the size of a polyp after polypectomy.
Positive predictive value
The positive predictive values of a positive test result were 10.9% for invasive cancer and 35.0% for adenoma. The values for cancer were higher for Scotland and in men. All values compared favourably to those of the Nottingham study in the 50-69 age range (table 2).
Table 2 Positive predictive values of colonoscopies conducted in screening pilot and Nottingham trial
Stage distribution of screen detected cancer
Overall, 552 cancers detected by screening were diagnosed, of which 92 (16.6%) were invasive polyp cancers, removed at colonoscopy. In the pilot, if polyp cancers with no information on staging (colectomy to remove residual disease after polypectomy not carried out) were classified as Dukes's stage A, then 265 (48%) of the screen detected cancers would be at stage A and five (1%) at stage D (with metastases; fig 4).
Fig 4 Dukes's stage of cancers detected by screening in pilot. "Polyp cancers" are defined as invasive cancers removed at colonoscopy when colectomy was not carried out
The proportions of screen detected cancers presenting at Dukes's stages A or B were similar for England and Scotland. Both were comparable to the Nottingham values at the first invitation to participate (table 3).
Table 3 Dukes's stage of colorectal cancer in pilot and in Nottingham trial at first invitation to participate. Values are numbers (percentages)
Neoplasia detection rates
The cancer detection rate for the pilot was 1.62 per 1000 people screened, and 6.91 for all neoplasia (cancers and adenomas). The cancer detection rate in England was comparable to the 50-69 age range in the prevalence round of the Nottingham trial whereas it was higher in Scotland (table 4). The overall detection rate for neoplasia was higher in Scotland than in England, particularly for men.
Table 4 Detection rates for cancer and neoplasia per 1000 people screened (faecal occult blood testing complete) for pilot and prevalence screen of Nottingham trial
Discussion
Hardcastle JD, Bennett DH, Whynes DK. Mass screening: European/UK perspective. In: Young GP, Rozen P, Levin B, eds. Prevention and early detection of colorectal cancer. London: WB Saunders, 1996: 275-88.
Hardcastle JD, Chamberlain JO, Robinson MHE, Moss SM, Amar SS, Balfour TW, et al. Randomised controlled trial of faecal occult blood screening for colorectal cancer. Lancet 1996;348: 1472-7.
Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecal occult blood test. Lancet 1996;348: 1467-71.
Fentiman I. Detection and treatment of early breast cancer. Philadelphia: Lippincott, 1990: 618.
Steele RJC, Parker R, Patnick J, Warner J, Fraser C, Mowat NA, et al. A demonstration pilot for colorectal cancer screening in the United Kingdom: a new concept in the introduction of health care strategies. J Med Screen 2001;8: 197-202.
Mandel JS, Bond JH, Church JR, Snover DC, Bradley GM, Schuman LM, et al. Reducing mortality from colorectal cancer by screening for faecal occult blood. N Engl J Med 1993;328: 1365-71.
De Koning HJ. Assessment of nationwide cancer-screening programmes. Lancet 2000;355: 80-1.
Gryd-Hansen D, Sogaard J, Kronborg O. Colorectal cancer screening: efficiency and effectiveness. Health Econ 1998;7: 9-20.
Thomas-Gibson S, Thapar C, Shah SG, Saunders BP. Colonoscopy at a combined district general hospital and specialized endoscopy unit: lessons from 505 consecutive examinations. J R Soc Med 2002;95: 194-7.
Department of Health. The NHS cancer plan: a plan for investment, a plan for reform. London: DoH, 2000.
Scottish Intercollegiate Guidelines Network. Management of colorectal cancer: a national clinical guideline. Edinburgh: SIGN. Mar 2003: 6. (Guideline No 67.)
Atkin WS, Saunders BP. Surveillance guidelines after removal of colorectal adenomatous polyps. Gut 2002;51(suppl v): v6-9.
Pathmakanthan S, Murray I, Smith K, Heeley R, Donnelly M. Nurse endoscopists in United Kingdom health care: a survey of prevalence, skills and attitudes. J Adv Nurs 2001;36: 705-10.
Pye G, Christie M, Chamberlain JO, Moss SM, Hardcastle JD. A comparison of methods for increasing compliance within a general practitioner based screening project for colorectal cancer and the effect on practitioner workload. J Epidemiol Community Health 1988;42: 66-71.
Muller AD, Sonnenberg A. Protection by endoscopy against death from colorectal cancer: a case-control study amongst veterans. Arch Intern Med 1995;155: 1741-8.
UK Flexible Sigmoidoscopy Screening Trial Investigators. Single flexible sigmoidoscopy screening to prevent colorectal cancer: baseline findings of a UK multicentre randomized trial. Lancet 2002;359: 1291-300.
Rasmussen M, Fenger C, Kronborg O. Diagnostic yield in a biennial Haemoccult-II screening programme compared to a once-only screening with flexible sigmoidoscopy and Haemoccult-II. Scand J Gastroenterol 2003;38: 114-8.
Department of Health Press Release 2003/0047 (www.info.doh.gov.uk/doh/intpress.nsf/page/2003-0047) (accessed Aug 2003).
Scottish Executive Health Department. Cancer in Scotland Action for Change Bowel Cancer Framework for Scotland. Edinburgh: SEHD, 2004.
Steele RJC, Gnauck R, Hrcka R, Kronborg O, Kuntz C, Moayyedi P, et al. Methods and economic considerations. Report from the ESGE/UEGF workshop on colorectal cancer screening. Endoscopy 2004;36: 349-53.
Tengs TO, Adams ME, Pliskin JS, Safran DG, Siegel JE, Weinstein MC, et al. Five hundred life-saving interventions and their cost-effectiveness. Risk Analysis 1995;15: 369-90.(, for the UK Colorectal C)