ESGE Workshop on Colorectal Cancer Screening: Summary and Outlook

The reports published here on the European Society of Gastrointestinal Endoscopy (ESGE) workshop on colorectal cancer screening held in Oslo [1] [2] [3] [4] provide important documentation, summing up and analyzing valuable data in a very concise form. They present the findings of four working groups from the meeting - on methods and economic considerations; legal and ethical considerations; and public awareness and lobbying.

The most detailed report, by Steele et al., is from the first working group, concerned with assessing screening methods and their economic implications. The guaiac-based fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy are discussed in detail. A pilot study commissioned by the British government has now joined the well-known results of large-scale FOBT studies conducted in Denmark [5], England [6], and Minnesota [7], and the meta-analysis including French and Swedish studies [8]. The aim of the British pilot study was to examine whether FOBT screening should be included in the national screening program; the conclusion was positive [9]. The authors describe the benefits and limitations of FOBT in detail, and the need to develop a new test with better sensitivity and specificity levels is also noted. A randomized study has also been conducted in the United Kingdom, using a single sigmoidoscopy in individuals aged between 55 and 64 as the screening test. Larger numbers of adenomas and a higher rate of colorectal cancer, with 62 % in stage A, were discovered. Sigmoidoscopy is of course limited to the length of the endoscope and the extent of the colon that is visible with it, and more cannot be expected [10]. The authors describe colonoscopy as being highly sensitive and specific for identifying adenomas and colorectal cancer, and state that ”many regard it as self-evident that it should be used as a screening test. However, colonoscopy is expensive, invasive and potentially dangerous, and the evidence supporting its use for population screening is not strong” [1]. There is indeed a lack of randomized and controlled studies (RCTs) on the use of colonoscopy as a screening test, and the level of compliance with population screening programs is not known. The authors take to task the commendable United States National Polyp Study [11], criticizing its use of a historical control group not derived from the same population as the cases. It would of course have been ideal to use a control group of patients undergoing colonoscopy without polypectomy. However, establishing a group of this type is not feasible and for several reasons even unethical, and I suspect that Winawer et al. would have had little success in recruiting a control group of this type. The organizers of the carefully planned PRISMA study in Germany recently faced similar difficulties. Patients who were positive for Helicobacter pylori chose eradication therapy in preference to being assigned to the control group.

The importance of evidence-based studies cannot be overestimated. In practice, well-planned case-control and cohort studies controlled by an independent authority can be accepted as adequate evidential proof. Another parameter for clinical studies that should not be underestimated is patient satisfaction. Recent studies have shown that this is very high with modern colonoscopy in which premedication is administered as needed [12]. The personal yield when a healthy colon is found stands in contrast to the low statistical yield of colonoscopy as a screening method for colorectal cancer. It would certainly be desirable to have a preliminary test that would allow at-risk patients to be selected for colonoscopy. Such a practicable fecal test is not yet available. CT colonography using specialized software to produce a three-dimensional view and with electronic cleansing has achieved high sensitivity rates, even for polyps smaller than 1 cm in diameter [13] but it currently pushes costs to astronomically high levels - quite apart from the radiation burden involved.

Now that colonoscopy has already been introduced as a primary screening method in European countries and the United States, what should gastroenterologists there do? The method has the highest sensitivity and specificity levels; it has been shown that it is capable of diagnosing 90 - 95 % of colorectal carcinomas and their precursor lesions; and it can prevent colorectal carcinoma by allowing adenomas to be removed. Should this method now be set aside until the results of a randomized and controlled study become available? I think not. Population screening is aimed not at individuals, but at reducing the burden of a disease for society. This implies that a test that has a high rate of uptake and relatively low costs is needed. These criteria do in fact probably apply to colonoscopy - and not only in Poland and Hungary, but also in Germany, where health-insurance associations pay € 165 for colonoscopy and € 35 for polypectomy.

The section reviewing the health-care economics of screening methods is interesting. The authors’ own calculations are based on a statistical model of conditions in the United Kingdom, and the costs presented are based on conditions there. However, the costs of endoscopy vary substantially in different countries in Europe.

An important variable in considerations of health-care costs is population compliance. The authors’ assumption that compliance with one of the strategies for colorectal cancer screening amounts to 50 % has not in fact yet been achieved anywhere. In Bavaria, representing approximately 10 % of the population of Germany, there has been a 500-fold increase in the rate of screening colonoscopies within 1 year, but the absolute numbers have only reached about 5 %. Interestingly, in the Swiss cantons in which colonoscopy was applied in a feasibility study, 80 % of the informed population have chosen colonoscopy as their preferred screening method [14]. These figures raise the hope that the efforts being made by scientific societies, professional associations, charitable foundations, health-insurance associations, and other public institutions in Europe will help overcome the well-known barriers to colorectal cancer screening, and to colonoscopy in particular.

The summary from the working group on legal and ethical considerations is well worth reading [4]. The working group dealt with many aspects of the topic, and in particular with the fact that while normal healthy individuals who have an average risk of contracting colorectal cancer can benefit substantially, they can also suffer serious detriment due to an overlooked colorectal cancer, or due to a complication of the endoscopic examination. To the Hippocratic injunction, ”first do no harm” the principle of ensuring the greatest benefit for the largest number of people is added.

Important and obvious legal aspects include, for example, the fact that there is a responsibility to ensure a high quality in colonoscopies by providing fully trained endoscopists and adequate endoscopy units, as well as monitoring with regard to the outcome. German health authorities have reduced the number of doctors licensed for screening colonoscopy to less than 50 %, namely to those who performed at least 200 colonoscopies in the last 2 years and they have ordered microbiological studies of endoscopy in regular intervals. The criticism of mammography and cervical cytology that has appeared in the medical literature and lay press was also discussed. Consideration should certainly be given to the ethical problems connected with cancer screening programs and the associated legal issues before this type of program is initiated. The mortality and complication rates cited here do not correspond to experience with outpatient colonoscopies in Germany [12]. Many large studies in recent years have reported zero mortality with purely diagnostic colonoscopy in screening programs, but 10 000 or more colonoscopies evidently have to be included in the statistics before rare complications become noticeable.

The note on potential legal risks caused by individual psychological injury is also important, since campaigns for colorectal cancer might be capable of arousing anxiety in society. Some journalists in Germany are also currently ”blowing up” the issue that media campaigns on colorectal cancer are stirring up public anxiety. The journalists are defaming the work of scientific societies and charitable foundations devoted to fighting colorectal cancer, using H. Thornton’s statement that ”screening is a business aimed at producing patients” and claiming that anxiety is being misused as a central element of the public screening campaign in order to force citizens to participate in it.

Another important issue is whether general practitioners should inform their patients about the availability of screening. An influential medicolegal expert in Germany believes that the patient has a right to receive this information. However, a case of this type has not yet come before a German court.

The reports from the other two working groups, presented by P. Rozen and G. Hoff, earn merit for their clarity of presentation and for their concision in dealing with complex matters [2] [3]. Both Rozen and Hoff are proven experts in the field, like all of the participants in the workshop, and the ESGE has made a valuable contribution to screening in Europe by organizing the meeting.

Unfortunately, the European Commission has presented the Council with a recommendation on cancer prevention that allegedly takes into account dissimilarities in the health-care systems in European countries and specifies only an occult blood test between the ages of 50 and 74 as the ”best practice strategy” and as a systematic screening examination for colorectal carcinoma [15]. The use of flexible colonoscopy to achieve early recognition of colorectal carcinoma is merely mentioned under ”potentially promising screening examinations.“ In 1997, 221 000 European citizens contracted colorectal cancer, and 111 000 died of it. In view of these shocking figures, the European recommendations should not place obstacles in the way of already initiated and continuing screening programs, particularly when they include colonoscopy.

References

• 1 Steele R JC, Gnauck R, Hrcka R. et al . Methods and economic consideration: Group 1 report. ESGE/UEGF Colorectal Cancer-Public Awareness Campaign. The Public/Professional Interface Workshop. Oslo, Norway, June 20 - 22, 2003.  Endoscopy. 2004;  36 349-353
• 2 Rozen P, Blanchard J, Campbell D. et al . Implementing colorectal cancer screening: Group 2 report. ESGE/UEGF Colorectal Cancer-Public Awareness Campaign. The Public/Professional Interface Workshop. Oslo, Norway, June 20 - 22, 2003.  Endoscopy. 2004;  36 354-358
• 3 Hoff G, Blanchard J, Crespi M. et al . Public Awareness and Lobbying: Group 3 report. ESGE/UEGF Colorectal Cancer-Public Awareness Campaign. The Public/Professional Interface Workshop. Oslo, Norway, June 20 - 22, 2003.  Endoscopy. 2004;  36 359-361
• 4 Axon A TR, Beilenhoff U, James T. et al . Legal and Ethical Consideration: Group 3 report. ESGE/UEGF Colorectal Cancer-Public Awareness Campaign. The Public/Professional Interface Workshop. Oslo, Norway, June 20 - 22, 2003.  Endoscopy. 2004;  36 362-365
• 5 Kronborg O, Fenger C, Olsen J. et al . Randomised study of screening for colorectal cancer with faecal occult blood test.  Lancet. 1996;  348 1467-1471
• 6 Hardcastle J D, Chamberlain J O, Robinson M HE, Moos S M, Amar S S, Balfour T W. et al . Randomised controlled trial of faecal occult blood screening for colorectal cancer.  Lanct. 1996;  348 1472-1477
• 7 Mandel J S, Bond J H, Church J R. et al . Reducing mortality from colorectal cancer by screening for faecal occult blood.  N Engl J Med. 1993;  328 1365-1371
• 8 Tower B, Irwig L, Glasziou P. et al . A systematic review of the effects of screening for colorectal cancer using the faecal occult blood test, Hemoccult.  BMJ. 1998;  317 559-565
• 9 Evaluation of the UK colorectal screening pilot. A report for the UK Department of Health. Health June 2003
• 10 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 1291-1300
• 11 Winawer S J, Zauber A G, Ho M N. et al . Prevention of colorectal cancer by colonoscopy polypectomy. A national polyp study work. N Engl J.  Med.. 1993;  329 1977-1981
• 12 Sieg A, Hachmoeller-Eisenbach U, Eisenbach T h. Prospective evaluation of complications in outpatient GI endoscopy: a survey among German gastroenterologists.  Gastrointest Endosc. 2001;  53 620 -627
• 13 Pickhardt P J, Choi J R, Hwang I. et al . Computed tomographic virtual colonoscopy to screen for colorectal neoplasia.  New Engl J Med. 2003;  349 2191-2220
• 14 Brunner G. Personal Communication. 
• 15 Commission of the European Comunities .Proposal for a recommendation of the council on cancer prevention. Brussels; 5.52003; 2003/0093 (CNS)