Preventive colonoscopies results
Between the beginning of online individual data management in January 2006 and the end of 2011, a total of 78 836 individuals were examined by preventive colonoscopy, of whom 68 527 (86.9%) were examined by a FOBT follow-up colonoscopy (indicated by a positive FOBT) and 10 309 (13.1%) by a screening colonoscopy (starting in January 2009 and indicated by ≥55 years of age). In Table 2, the main early performance indicators including the completeness of a colonoscopy, PPV, and a standardized ratio for the detection of adenomas, advanced adenomas, and carcinoma in case of a FOBT follow-up colonoscopy, and similarly, a completion and detection rate for the same categories in case of a screening colonoscopy are summarized.
The overall proportion of a complete (total) colonoscopy is higher in screening colonoscopy compared with a FOBT follow-up colonoscopy (97.8 vs. 95.7% in 2011). The proportion is still higher if we exclude patients eventually diagnosed with CRC (97.9 vs. 96.1% in 2011). In both of these approaches, the improvement over time is notable, especially in a FOBT follow-up colonoscopy.
The PPV of a FOBT for the detection of adenomas and advanced adenomas has been increasing constantly from 28.8% (adenomas) and 13.5% (advanced adenomas) in 2007 to 35.4 and 16.7%, respectively, in 2011 (for both trends P<0.001). An opposite trend can be observed for the detection of carcinomas, where the values decreased from 6.3% in 2006 to 3.6% in 2011 (P<0.001). The analyses of detection rates for screening colonoscopy (introduced in 2009) showed a significant change only in advanced adenoma detection, with a decrease in rate from 8.2% in 2009 to 7.3% in 2011 (P=0.01). A detailed overview of PPV and detection rates for adenomas and cancers, including the age-specific and sex-specific estimates, can be found in Table 3, and Figs 4 and 5.
Altogether, a total of 25 255 adenomas (of which 11 860 were advanced) were removed endoscopically and 3379 carcinomas were diagnosed between 2006 and 2011. In comparison with population data, stage distribution of screen-detected cancers is much more favorable, with 65.7% in stage I or II diagnosed in 2011 (Table 4). There was a statistically significant increase in the proportion of cancers detected in stage I between 2006 and 2011 (P=0.048).
The registry also includes recorded colonoscopy complications. A total of 20 cases of perforations (0.03% of all colonoscopies) have been reported in diagnostic procedures, with 44 cases of perforation and 285 cases of major bleeding during an endoscopic polypectomy (0.13 and 0.82% of all therapeutic colonoscopies, respectively).
European guidelines quality indicators
The European CRC screening and diagnosis guidelines set a total of 30 early performance indicators and four long-term impact indicators. The majority of them (70%) have not been defined in exact numbers but in the rest of them, the accepted and recommended values have been firmly established. The majority of early performance indicators are currently evaluated within the Czech CRC screening program (Table 5). Three long-term impact indicators (CRC incidence and mortality, and advanced-stage disease rates) are monitored, with no remarkable improvement since the screening program started. At this time, the data on interval cancer are not available because of the absence of a direct link between screening and cancer registry.
The Czech Republic belongs to the family of developed countries with the highest CRC incidence, mortality, and prevalence rates. Although the probability of 5-year survival is gradually increasing because of the continuing progress in clinical oncology, the statistics are significantly affected by an alarming proportion of primarily diagnosed metastatic diseases. The persisting high incidence of advanced stages precludes considerable reduction in mortality, which can be reached only over a long period of a running screening program. Therefore, after two successful pilot projects, the organized nonpopulation-based Czech National CRC screening program was launched 11 years ago only as the second screening program following a world premiere program launched in Germany (Sieg and Friedrich, 2009). The program is currently not population-based, which is recognized as the most optimal program setting defined by identification and personal invitation of each patient from the eligible target population (Karsa et al., 2008; Benson et al., 2012). Nevertheless, monitoring, evaluation, and management of the Czech program have been set up together with a network of quality-controlled screening centers. The population coverage by screening examinations has not yet reached the recommended level of 65% or the ‘acceptable’ level of 45%. However, the consistent and remarkable increase in the FOBT coverage to the recent 23% in 2010 is encouraging. The positive development in the most recent years is likely associated with the newly implemented design of the program in 2009 and recently initiated information campaigns. The introduced option to use FIT testing was well received and adopted mainly by gynecologists, who were newly included in the program. As a result, the fastest growing group in the program consists of women aged 50–69 years, who tend to visit gynecologists regularly throughout the year. From daily clinical practice, it is known that qualitative tests are preferred by the majority of general practitioners and gynecologists probably because of the favorable reimbursement rates for these tests. Nevertheless, as has been proven previously, that there is a considerable difference in diagnostic performance of these tests; therefore, a careful evaluation is desirable (Hundt et al., 2009). The more intensive use of quantitative FIT should be encouraged in the future as long as these tests are acceptable to the medical specialists. Offering the choice of screening colonoscopy, starting at age 55, has influenced individuals who prefer a one-step endoscopy program, especially men. The other reason for coverage improvement has been strong media support, advertisements, and particularly two nationwide education campaigns.
The European guidelines for quality assurance in CRC screening and diagnosis represent one of the most up-to-date and comprehensive evidence-based medicine guidelines currently available. The introduced set of recommendations is to be adapted by national CRC screening programs to improve their performance. In terms of the evaluation and interpretation of screening outcomes, two types of quality control indicators (early performance indicators and long-term impact) should be assessed. Because of the large differences between individual national CRC screening programs and underlying population characteristics, there are no universally applicable rules. Therefore, the exact acceptable and recommended levels are given only in the minority of indicators (30%). Only part of the early performance indicators can be assessed for the Czech CRC screening program because of the current nonpopulation setting owing to the absence of personal invitations. As the currently provided tests are both gFOBT and FIT, the average overall positive rate of stool testing, at 6.1%, cannot be directly compared with the previously observed rates of 1.5–8.5% for gFOBT and 4.4–11.1% for FIT. A favorable distribution in screen-detected cancers (47% in stage I) clearly shows the importance of the Czech program from an individual patient perspective. In terms of the outcome of screening colonoscopy, three main quality indicators are monitored: adenoma detection rate, colonoscopy completion rate, and number of adverse events. A recent study carried out in Poland has proven that the endoscopist’s rate of detection of adenomas is significantly associated with the risk of interval CRC, with most favorable results for rates of over 20% (Kaminski et al., 2010). Hence, the adenoma detection rate of 25% achieved in the Czech program seems very promising. In contrast, an overall higher incidence of CRC with a likelihood of a higher prevalence of detectable colorectal neoplasia in the Czech population should also be taken into account. In both types of colonoscopy setting, the improvement in completion rate with time is noticeable, especially in the case of the screening colonoscopies. This may be the result of the more systematic quality control requiring documentation of images of the cecum, which is now obligatory. The percentage of procedure complications does not differ from the previously published data (Panteris et al., 2009). The colonoscopy record should include any complication known to the gastroenterologist caused by the described endoscopy; however, some later complications could have been missed, as the cohort was not followed up. Nevertheless, this limitation is shared with other registry studies (Pox et al., 2012).
All tools necessary for the evaluation of the program's long-term impact indicators have been implemented. Although there are three major available databases in the Czech Republic, the collection of high-quality data from them is yet to be interconnected. Unfortunately, without this interconnection, the analysis of interval cancers as an important parameter evaluated in both FOBT-based (Steele et al., 2012) and colonoscopy-based (Baxter et al., 2011) programs cannot be carried out. For the early performance indicators, the absence of data linkages precludes the monitoring of FOBT program detection rates. The effect of screening on mortality reduction has been broadly shown by randomized control trials based on FOBT [13–25%, (Hewitson et al., 2008)] or flexible sigmoidoscopy [22–31%, (Atkin et al., 2010; Segnan et al., 2011; Schoen et al., 2012)]. However, in a nationwide CRC screening program, only an indirect relation to the decrease in mortality can be observed, especially with a high prevalence of CRC as in the case of the Czech Republic.
The Czech National CRC Screening program has achieved quality levels at which clinical trials proved to effectively reduce the CRC burden. The current insufficient program coverage results in the lack of population impact. The implementation of a population-based approach using personal invitations of all eligible persons is therefore clearly justified. This approach would also provide an effective framework for the evaluation of program quality and impact through the linkage of records from the population and cancer registry.
The authors would like to thank the Members of the Board for the CRC Screening (K. Balihar, M. Benes, J. Bures, T. David, P. Dite, J. Dolecek, P. Fric, A. Hep, J. Hnanicek, J. Huml, P. Igaz, J. Janku, R. Keil, D. Klobucar, M. Kment, P. Kocna, D. Kohoutova, L. Kolonderova, A. Kovarikova, D. Novotny, V. Prochazka, A. Richterova, O. Shonova, B. Seifert, A. Skrivanek, M. Slobodova, J. Stehlik, A. Sachlova, J. Spicak, J. Stuksa, T. Svestka, M. Tomanová, O. Urban, M. Varga, P. Zdenek) for their effort in the Czech CRC screening organization and to the Czech healthcare payers and the National Reference Centre for providing high-quality representative data on population coverage reached by adopted screening modalities.
The development of methodology for the monitoring of the CRC screening program is part of the specific research grant project ‘Mathematical and statistical models in the evaluation of cancer screening programs’ (Masaryk University, grant no. MUNI/A/0828/2011). The project was also supported by the grant IGA Ministry of Health of the Czech Republic no. NT 13673-4/2012.
Conflicts of interest
The are no conflicts of interest.
Atkin WS, Edwards R, Kralj-Hans I, Wooldrage K, Hart AR, Northover JM, et al..Once-only flexible sigmoidoscopy screening
in prevention of colorectal cancer
: a multicentre randomized controlled trial.Lancet2010;375:1624–1633.
Baxter NN, Sutradhar R, Forbes SS, Paszat LF, Saskin R, Rabeneck L.Analysis of administrative data finds endoscopist quality measures associated with postcolonoscopy colorectal cancer
Benson VS, Atkin WS, Green J, Nadel MR, Patnick J, Smith RA, et al..Toward standardizing and reporting colorectal cancer screening
indicators on an international level: The International Colorectal Cancer Screening
Network.Int J Cancer2012;130:2961–2973.
Brenner H, Gefeller O, Hakulinen T.Period analysis for ‘up-to-date’ cancer survival data: theory, empirical evaluation, computational realisation and applications.Eur J Cancer2004;40:326–335.
Corazziari I, Quinn M, Capocaccia R.Standard cancer patient population for age standardising survival ratios.Eur J Cancer2004;40:2307–2316.
Dusek L, Muzik J, Kubásek M, Koptikova J, Zaloudik J, Vyzula R.Epidemiology of malignant tumors in the Czech Republic
Version 7.0, ISSN 1802-88612007..Czech Republic
:Masaryk UniversityAvailable at: http://www.svod.cz
[Accessed 30 October 2011].
Ederer F, Axtell LM, Cutler SJ.The relative survival rate: a statistical methodology.Natl Cancer Inst Monogr1961;6:101–121.
Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM.GLOBOCAN 2008, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 102010..Lyon:International Agency for Research on CancerAvailable at: http://globocan.iarc.fr
[Accessed 30 November 2012].
Hakulinen T.Cancer survival corrected for heterogeneity in patient withdrawal.Biometrics1982;38:933–942.
Hewitson P, Glasziou P, Watson E, Towler B, Irwig L.Cochrane systematic review of colorectal cancer screening
using the fecal occult blood test
(Hemoccult): an update.Am J Gastroenterol2008;103:1541–1549.
Hundt S, Haug U, Brenner H.Comparative evaluation of immunochemical fecal occult blood tests for colorectal adenoma detection.Ann Intern Med2009;150:162–169.
Kaminski MF, Regula J, Kraszewska E, Polkowski M, Wojciechowska U, Didkowska J, et al..Quality indicators for colonoscopy
and the risk of interval cancer.N Engl J Med2010;362:1795–1803.
Karsa LV, Anttila A, Ronco G, Ponti A, Malila N, Arbyn M, et al..Cancer screening
in the European Union. Report on the implementation of the Council Recommendation on cancer screening
– First report. ISBN 978-92-79-08934-32008.Luxembourg:European Communities, by the services of the European Commission.
Moss S, Ancelle-Park R, Brenner HSegnan N, Patnick J, von Karsa L.Evaluation and interpretation of screening
outcomes.European guidelines for quality assurance in colorectal cancer screening
and diagnosis2010:1st ed..Luxembourg:Publications Office of the European Union;72–102.
Panteris V, Haringsma E, Kuipers EJ.Colonoscopy
perforation rate, mechanism and outcome: from diagnostic to therapeutic colonoscopy
Pox CP, Altenhofen L, Brenner H, Theilmeier A, Stillfried DV, Schmiegel W.Efficacy of a nationwide screening colonoscopy
program for colorectal cancer
Schoen RE, Pinsky PF, Weissfeld JL, Yokochi LA, Church T, Laiyemo AO, et al..Colorectal-cancer incidence and mortality with screening
flexible sigmoidoscopy.N Engl J Med2012;366:2345–2357.
Segnan N, Armaroli P, Bonelli L, Risio M, Sciallero S, Zappa M, et al..Once-only sigmoidoscopy in colorectal cancer screening
: follow-up findings of the Italian Randomized Controlled Trial-SCORE.J Natl Cancer Inst2011;103:1310–1322.
Sieg A, Friedrich K.Perspectives of colorectal cancer screening
in Germany 2009.World J Gastrointest Endosc2009;1:12–16.
Sobin LH, Gospodarowicz MK, Wittekind Ch.TNM classification of malignant tumors2009:7th ed..Oxford:Wiley-Blackwell.
Steele RJ, McClements P, Watling C, Libby G, Weller D, Brewster DH, et al..Interval cancers in a FOBT-based colorectal cancer
programme: implications for stage, gender and tumour site.Gut2012;61:576–581.
.International statistical classification of diseases and related health problems, 10th revision (ICD-10)1992.Geneva:World Health Organization.
.WHO Statistical Information System2010.Geneva, Switzerland:WHO DatabankAvailable at: http://www.who.int/whosis
[Accessed 4 September 2010].
Zastera J, Roewer L, Willuweit S, Sekerka P, Benesova L, Minarik M.Assembly of a large Y-STR haplotype database for the Czech population and investigation of its substructure.Forensic Sci Int Genet2010;4Issue 3e75–e78.
Zavoral M, Suchanek S, Zavada F, Dusek L, Muzik J, Seifert B, et al..Colorectal cancer screening
in Europe.World J Gastroenterol2009;47:5907–5915.
Keywords:© 2014 Lippincott Williams & Wilkins, Inc.
colonoscopy; colorectal cancer; Czech Republic; fecal occult blood test; screening