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Colorectal cancer prevention in the Czech Republic: time trends in performance indicators and current situation after 10 years of screening

Suchanek, Stepana; Majek, Ondreje; Vojtechova, Gabrielaa; Minarikova, Petraa; Rotnaglova, Barboraa; Seifert, Bohumilb; Minarik, Marekc; Kozeny, Paveld; Dusek, Ladislave; Zavoral, Miroslava

European Journal of Cancer Prevention: January 2014 - Volume 23 - Issue 1 - p 18–26
doi: 10.1097/CEJ.0b013e328364f203
Research Papers: Gastrointestinal Cancer
Free

The incidence and mortality of colorectal cancer (CRC) in the Czech Republic is significant. The National CRC Screening Program started in 2000 and was further enhanced in 2009. In 2010, the European Guidelines were introduced. The aim of the present trend study was to evaluate the quality of the Czech National Colorectal Cancer Screening Program using early performance and long-term impact indicators. The screening program has been assessed using data from three sources: the Czech National Cancer Registry, the Czech National Reference Centre, and the Czech CRC Screening Registry. The data were compared with a set of recommended quality control indicators. Between 2006 and 2010, a total of 1 881 299 fecal occult blood tests were performed, of which 87 397 were positive (4.6%). Until 2011, a total of 68 527 fecal occult blood test follow-up colonoscopies were performed. In addition, between 2009 and 2011, a total of 10 309 screening colonoscopies were performed. As a result, a total of 25 255 adenomas (32.0% rate) and 3379 CRCs (4.3% rate) were detected. A trend of cancer detection in earlier stages has been observed. The overall program coverage has increased to 22.7% of the target population in 2010. The majority of European guidelines’ quality indicators for nonpopulation-based programs were implemented in the Czech National CRC Screening program. An improvement in program management was accompanied by an increase in coverage as well as other performance indicators.

aDepartment of Medicine, 1st Faculty of Medicine, Military University Hospital

b1st Faculty of Medicine, Institute of General Practice, Charles University

cCenter for Applied Genomics of Solid Tumors, Genomac Research Institute

dNational Reference Centre, Prague

eInstitute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic

Correspondence to Stepan Suchanek, MD, Department of Medicine, 1st Faculty of Medicine, Military University Hospital, Charles University, U Vojenske nemocnice 1200, CZ 169 02, Prague 6, Czech Republic Tel: +420 972 203 063; fax: +420 972 203 068; e-mail: stepan.suchanek@uvn.cz

Received January 28, 2013

Accepted June 28, 2013

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Introduction

Colorectal cancer (CRC) is the second most frequent malignancy in Europe. The most recent data show disturbing epidemiological trends in Central and Eastern European countries (Hungary, Slovakia, and the Czech Republic) (Ferlay et al., 2010). The high incidence rates in these countries are caused by a combination of common external risk factors associated with unhealthy lifestyle along with close ancestry roots resulting in similarities in inherited predispositions (Zastera et al., 2010). A large proportion of CRCs are primarily diagnosed in advanced stages, where treatment options are already very limited and, not the least, cost-demanding for the healthcare system (Dusek et al., 2005). CRC thus represents a serious healthcare problem in the Czech Republic, and its high mortality and morbidity are the main reasons for the implementation of an effective screening program. Its primary aim is the reduction of CRC mortality.

The National CRC Screening Program in the Czech Republic was launched in June 2000, relying mainly on the performance of a guaiac fecal occult blood test (gFOBT). A biennial testing was offered to asymptomatic individuals older than 50 years of age through a network of general practitioners. No upper age limit for the participation in the screening program was imposed. In case of a positive test, a follow-up colonoscopy was conducted. Since 2006, high-quality individualized data are being collected and evaluated to meet the EU recommendations for the quality control of screening programs (Zavoral et al., 2009). To increase the compliance, a new program design was introduced in 2009. The three major improvements implemented included the use of an immunochemical fecal occult blood test [iFOBT, fecal immunochemical testing (FIT)], screening colonoscopy, and the involvement of gynecologists. The aim of the present work was to report and evaluate the quality of the Czech National CRC Screening Program using early performance and long-term impact indicators recommended by European guidelines.

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Materials and methods

The screening program has been assessed on the basis of the combination of data from three registries: the Czech National Cancer Registry (CNCR), the Czech National Reference Centre, and the Czech CRC Screening Registry. The data were evaluated against a set of recommended quality control indicators.

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Cancer epidemiology monitoring

The CNCR (http://www.svod.cz) is an essential source of data on cancer statistics that covers the entire cancer patient population of the Czech Republic starting from 1976. The CNCR contains the following: personal patient data, malignant tumors, and their detailed diagnostic description (including morphology classification, and stage), patients’ treatment, and post-treatment follow-up entries. The population-based monitoring thus enables estimation of the disease incidence and mortality, the distribution of clinical stages, as well as cancer treatment and survival rates. Malignant neoplasms are recorded according to the International Classification of Diseases for Oncology (10th revision) (World Health Organization, 1992). Tumor staging is performed on the basis of the TNM classification system (Sobin et al., 2009). Standardized death certificates (internationally recommended by WHO) are implemented to collect precise individual data on the cause of death (World Health Organization, 2010).

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Healthcare administrative data monitoring

In the Czech Republic, all residents are covered by public health insurance. The National Reference Centre (http://www.nrc.cz) holds complete information about the coverage of preventive and diagnostic colonoscopies, as well as information on the FOBTs performed. The detailed data on health insurance claims can thus be used to monitor the screening program.

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Screening center performance and quality monitoring

The Czech CRC Screening Registry holds data from a nationwide network of 168 medical facilities (Centers for screening colonoscopies) performing the preventive colonoscopies. The term ‘preventive colonoscopy’ covers both a follow-up colonoscopy (performed after a positive FOBT) and a screening colonoscopy (available to all individuals aged >55). The centers are required to meet strict quality criteria including adequate personnel, as well as material and instrumental capability, a recommended annual number of colonoscopies and endoscopic polypectomies performed, a quality control management system, and a plan for the management of complications. Each center is required to perform a minimum of 50 preventive colonoscopies annually. These colonoscopies are reported by an online form consisting of demographic data, the information on FOBT performed, and detailed description of the colonoscopy examination including the numbers of lesions found, their size, histology and staging, potential complications, and a confirmation of a total colonoscopy. The methodology of evaluation, as well as the screening results, is described on the national link (http://www.kolorektum.cz).

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European guidelines’ quality indicators

Supported by the Executive Agency for Health and Consumers of the European Commission, the European Guidelines for Quality Assurance in CRC Screening and Diagnosis have been published in 2010 (Moss et al., 2010). These recommendations put forward the early performance indicators and long-term impact indicators to assess the quality and effectiveness of the screening program. The early performance indicators include the program coverage and uptake, outcomes with FOBT and screening colonoscopy, and management of the screening program. The long-term impact indicators include the incidence and mortality, occurrence of the interval cancers, and the advanced-stage disease rates.

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Statistical analysis

Time trends in the CRC burden of the Czech population were assessed by crude incidence and mortality, whereas magnitude and change were evaluated by Poisson regression – an annual percent change (APC) including 95% confidence interval (CI) was estimated. Moreover, we estimated standardized (Corazziari et al., 2004) 5-year relative survival rates (Ederer et al., 1961) of CRC patients. Expected survival rates were derived according to Hakulinen (1982) using the Czech population life tables provided by the Czech Statistical Office to the Human Mortality Database (Human Mortality Database, 2012). Recent survival was estimated using period analysis (Brenner et al., 2004). Definitions of performance indicators follow recommendations of the European guidelines. The coverage by examination was estimated as the ratio of the number of individuals in the target population tested during the given screening interval (applicable to a certain age group and a screening method) and the overall number of individuals in the target population. To describe trends in positive predictive values (PPVs) adjusted for age and sex, indirect standardization was used to estimate standardized ratios for the detection of lesions. Logistic regression was used for statistical testing, adjusting for the age and sex of patients. All analyses were carried out using Stata 10.1 (StataCorp LP, College Station, Texas, USA).

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Results

Colorectal cancer burden assessment

Both incidence and mortality in the Czech Republic (population of 10.5 million of whom 3 806 582 are aged >50) have been constantly increasing since the initial record from the 1970s: APCs +3.5% (95% CI +3.4 to +3.6%) and +2.2% (95% CI +2.1 to +2.4%) for men; APCs +2.8% (95% CI +2.7 to +2.9%) and 1.5% (95% CI 1.3–1.7%) for women. The incidence and mortality rates stabilized or even decreased after the year 2000: – APCs +0.7% (95% CI +0.5 to +0.9%) and −1.1% (95% CI −1.4 to −0.8%) for men, APCs −0.4% (95% CI −0.7 to −0.2%) and −2.0% (95% CI −2.4 to −1.7%) for women (trends shown in Fig. 1). In 2010, 8136 individuals were diagnosed with CRC and 3934 died as a result of the malignant disease. The most current epidemiological data made available by CNCR show that in 2010, nearly a half of the cancers (47.1%) were diagnosed in advanced stages (III and IV) and the prevalence was 49 470 cases (Table 1). The 5-year relative survival rate in the period between 2005 and 2008 was 53.1% (95% CI 51.5–54.6%). This represents a notable increase compared with a decade earlier (1995–1999), when the survival rate was 43.6% (95% CI 42.1–45.1%).

Fig. 1

Fig. 1

Table 1

Table 1

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Program coverage analysis

Detailed data on the utilization of preventive colonoscopies have only been available since 2006, but the aggregated population data for FOBT coverage can be evaluated dating back to 2000. The time trends of program coverage in the target population can be seen in Fig. 2. There is a constant increase since the onset of the screening program. Recent data from 2010 confirm this trend with a coverage of 22.7%. This represents a notable increase from 17.9% in 2008. As can be seen in Fig. 3, the highest coverage is in the group of women younger than 70 years of age, whereas the lowest is among women older than 85 years of age. Certain differences are also observable among different regions of the Czech Republic, with the lowest coverage of 17.2% in the capital, Prague (data not shown). Similar interregional variability can be detected in FOBT positivity, with an overall value of 6.1%.

Fig. 2

Fig. 2

Fig. 3

Fig. 3

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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.

Table 2

Table 2

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.

Table 3

Table 3

Fig. 4

Fig. 4

Fig. 5

Fig. 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).

Table 4

Table 4

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).

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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.

Table 5

Table 5

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Discussion

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.

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Acknowledgements

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.

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Conflicts of interest

The are no conflicts of interest.

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Keywords:

colonoscopy; colorectal cancer; Czech Republic; fecal occult blood test; screening

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