Coverage by examinations associated with early detection of colorectal neoplasia in the Czech Republic.

BACKGROUND: Coverage by examinations is a crucial indicator of the future impact on the burden of colorectal cancer (CRC). The study aimed to evaluate coverage by examinations associated with CRC screening and early cancer detection of CRC in the Czech Republic. The burden of CRC was also assessed. METHODS: The novel nationwide administrative registry with individual data (period 2010-19) was used to evaluate coverage by examinations for screening faecal occult blood test and colonoscopy. In the second step, additional examinations for early CRC detection were included in the coverage calculation (complete coverage). Age-specific trends in CRC incidence (period 1977-2018) were investigated using Joinpoint regression. RESULTS: Coverage by screening examinations within recommended interval was around 30%. Complete coverage reached >37% and >50% at the 3-year interval. The coverage by examinations for the non-screening population aged 40-49 years was almost 4% and 5% (most of them were colonoscopies) at the 3-year interval. In age groups aged ≥50 years, we observed a significant annual decline, especially in the 50-69 age group, with recent annual decreases reaching up to 5-7%. The change in trend and the recent decline were also observed in the age group 40-49. CONCLUSIONS: More than half of the target screening population was covered by examinations potentially associated with early detection and subsequent treatment of colorectal neoplasms. The substantial coverage by potentially prophylactic examinations might be an explanation for the considerable decrease in CRC incidence.

Evaluation of the personalized invitation of Czech citizens to screening programs.

The Czech population has high burden of malignant tumors, and screening programs are therefore an essential part of cancer control policy. At the beginning of 2014 personalized invitation of Czech citizens for cancer screening programs was launched to promote higher coverage by screening. The aim of the paper is to present the up-to-date results of the personalized invitation. The data from health insurance companies were used to evaluate the volume of invitations for cancer screening programs and the participation rate after invitation in 2014-2017. During the first four years of the project, over 6 million invitations were sent (approximately 3 million individuals were invited). Participation rates after the first invitation in the breast, colorectal and cervical screening were 22.3%, 21.7% and 15.5%. However, the effect of personalized invitations decreases with repeated invitations to participate. Personalized invitation contributed to screening in hundreds of thousands citizens, but a large proportion of invited people still do not participate. It is necessary to encourage personalized invitation and discuss other strategies to motivate the public to participate in screening programs.

Chiroptical spectroscopy and metabolomics for blood-based sensing of pancreatic cancer.

To enable the early diagnosis of pancreatic cancer, the search for and definition of reliable biomarkers remain a subject of great interest, with the specificity and sensitivity of the currently used biomarkers being below the required values. We tested a novel diagnostic approach for pancreatic cancer based on the specific molecular signature of blood plasma components. To acquire more detailed structural information, structure-sensitive chiroptical methods (electronic circular dichroism and Raman optical activity) were supplemented by conventional Raman and infrared spectroscopies. The obtained spectra were subsequently processed by linear discriminant analysis yielding high values of specificity and sensitivity. In addition, to monitor not only large biomolecules as potential biomarkers but also those of low molecular weight, we conducted an analysis of blood plasma samples by using metabolomics. The achieved results suggest a panel of promising biomarkers for a reliable detection of pancreatic cancer.

Colorectal cancer screening.

In developed countries, colorectal cancer represents one of the most common malignancy. Screening of colorectal cancer, as a tool of secondary prevention, lead to reduction of the incidence and mortality of this disease. It allows to capture not only the precancerous lesions, but also the earlier stages of colorectal cancer, which can be effectively treated. In the Czech Republic the National colorectal cancer screening program was launched in 2000. It is focused to asymptomatic individuals over 50 years old, who have a negative personal and family history of colorectal neoplasia. The basic tools of colorectal cancer screening in the Czech Republic include fecal occult blood test and colonoscopy. Introduction a population based screening program by addressed invitation in 2014 led to increase the participation of the target population for screening. Key words: address invitation - colorectal cancer - epidemiology - population based screening - screening tests.

Increased tissue and circulating levels of dipeptidyl peptidase-IV enzymatic activity in patients with pancreatic ductal adenocarcinoma.

BACKGROUND/OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) is frequently heralded by an impairment of glucose homeostasis. Dipeptidyl peptidase-IV (DPP-IV) and fibroblast activation protein alpha (FAP) are aminopeptidases that regulate several bioactive peptides involved in glucoregulation, and are frequently dysregulated in cancer. The present study analyzes blood plasma levels and the quantity and localization of DPP-IV and FAP in PDAC tissues. METHODS: DPP-IV and FAP concentration and enzymatic activity were evaluated in the plasma from 93 PDAC, 39 type 2 diabetes mellitus (T2DM) and 29 control subjects, and in matched paired non-tumorous and tumor tissues from 48 PDAC patients. The localization of DPP-IV and FAP was determined using immunohistochemistry and catalytic histochemistry. RESULTS: The enzymatic activity and concentration of DPP-IV was higher in PDAC tumor tissues compared to non-tumorous pancreas. DPP-IV was expressed in cancer cells and in the fibrotic stroma by activated (myo)fibroblasts including DPP-IV(+)FAP(+) cells. FAP was expressed in stromal cells and in some cancer cells and its expression was increased in the tumors. Plasmatic DPP-IV enzymatic activity, and in particular the ratio between DPP-IV enzymatic activity and concentration in PDAC with recent onset DM was higher compared to T2DM. In contrast, the plasmatic FAP enzymatic activity was lower in PDAC compared to T2DM and controls and rose after tumor removal. CONCLUSIONS: DPP-IV-like enzymatic activity is upregulated in PDAC tissues. PDAC patients with recent onset diabetes or prediabetes have increased plasmatic DPP-IV enzymatic activity. These changes may contribute to the frequently observed association of PDAC and recent onset impairment of glucoregulation.

[Population colorectal cancer screening in the Czech Republic]. / Populacní screening kolorektálního karcinomu v Ceské republice.

UNLABELLED: Colorectal cancer (CRC) is the third most common malignant disease in developed countries and its incidence is steadily growing. This trend has a stable character despite the fact that CRC is among the best prevention influenced malignancies. National CRC screening program in the Czech Republic, which was established in year 2000, follows the world trends resulting from evidence based medicine. Currently, the basic tools of screening program are immunochemical fecal occult blood tests and colonoscopy in case of their positivity or screening colonoscopy. Stagnation of participating population resulted to initiation of address invitation of the target population in January 2014, in which citizens are regularly invited to attend the screening program and their response is subsequently evaluated. Screening that impacts whole target group is called population screening. KEY WORDS: colorectal cancer, population screening program, colonoscopy, fecal occult blood tests, address invitation.

[Early detection of sporadic pancreatic cancer]. / Casná detekce sporadického karcinomu pankreatu.

Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its prevalence continuously increases, mortality does not decrease, diagnosis is frequently late, radical surgery is limited to 15-20 % of patients, postoperative relapses are frequent, and chemotherapy has a palliative character. Preventive programs are the only possibility of improvement. In familial pancreatic cancer (FPC) the knowledge of the genetic mutation enables earlier entry of specialists into the surveillance program. The repeated use of high resolution imaging methods (including endoscopy and pancreatic cytology) may be followed by more frequent detection of the precursors and earlier stages of FPC. The identification of sporadic pancreatic cancer (SPC) depends fully on the construction of a multi-step and multi-disciplinary preventive program.

[KRAS mutation assay on EUS-FNA specimens from pacients with pancreatic mass]. / Vysetrení mutace KRAS v EUS-FNA preparátech pacientu s tumorem pankreatu.

Differential diagnosis of solid pancreatic masses using EUS FNA is in 1015 % of cases still challenging. Promising method, which helps to distinguish between chronic pancreatitis and cancer, is point mutations of the proto-oncogene KRAS test. This method is not established in routine clinical practice yet.Objectives were the determination of the sensitivity of the KRAS assay using various kinds of samples of patients with pancreatic mass and testing the effect of the presence of KRAS mutations on the prognosis of survival. 147 patients underwent EUS-FNA examination of pancreatic mass, accompanied by blood sampling with subsequent separation of plasma for the detection of circulating tumor DNA. Part of biopsy sample was left native in a stabilizing solution and part as cytological smear. Samples (native aspirates, cytological smears, plasma) were examined for the presence of KRAS mutation by heteroduplex analysis, denaturing capillary electrophoresis.Among 147 patients with pancreatic masses, 118 were diagnosed as a cancer, 26 chronic pancreatitis, 3 neuroendocrine tumor. In total 147 native aspirates, 118 cytological smears and 94 plasma samples were examined. The highest sensitivity of KRAS mutation was reached in the group of pancreatic cancer patients using cytology, in which 90 % of KRAS mutation was detected (106/118 of the samples). When using the native cellular aspirates, mutation was detected in 78 % (92/118 samples), and examination of plasma was positive in 27 % (24/90 samples). In four patients with chronic pancreatitis KRAS mutations was detected, although none has been cytologically confirmed as a cancer. Two of these four patients were confirmed in the course of the disease as a cancer, one patient died because of alcoholic delirium and the last one was indicated for surgery recently.Examination of KRAS mutations can be performed in all patients undergoing EUS-FNA, with the cytology being the most reliable type of sample for genetic tests. KRAS examination would be reasonable to introduce into routine clinical practice in a group of patients with unclear differential diagnosis of chronic pancreatitis, especially in those with suspicion of cancer in inflammatory terrain.Kexwords: pancreatic cancer, chronic pancreatitis, KRAS mutation , EUS-FNA.

[Pancreatic adenocarcinoma - early symptoms and screening]. / Adenokarcinom pankreatu - casné symptomy a screening.

Pancreatic adenocarcinoma is a dismal disease with a very serious prognosis and a very low 5-year survival. Local symptoms are present at a late stage of the disease and in the majority of cases do not enable radical surgery. Intervention is possible only in locally restricted tumor and remains the only chance of significant survival. At present, two early symptoms of this growth are known. They include impaired glucose tolerance or diabetes similar to but not identical with diabetes type 2, and a decrease of the body mass. They precede by a period of 2-3 years local symptoms that are late and cause the bad prognosis. The earlier diagnosis of pancreatic adenocarcinoma represents an urgent and serious task. The project of a screening program based on the use of the early symptoms may move the diagnosis of pancreatic adenocarcinoma to the earlier stage of the disease. The key-players for the most important first step of this program are general practitioners and ambulatory diabetologists.

[Endoscopic classification of colon and rectal neoplasias]. / Endoskopická klasifikace neoplazií tlustého streva a konecníku.

Along with the dynamic evolution of the new field of digestive endoscopy, the need of unified and unambiguous terms for endoscopic findings arose in the second half of the 20th century. In collaboration with the OMED members, professor Zdenek Maratka drew up the first internationally acknowledged terminology for digestive endoscopy which was used in the full range for a period of almost 20 years. The technical progress later brought with it endoscopes which made it possible to view flat lesions, frequently overlooked until then. The classification of the surface lesions was further specified by the Paris Classification which drew from the experience of Japanese endoscopists. Thanks to the new endoscopic methods of imaging mucosa in vivo and the pit-pattern and vascular-pattern classification, we can currently estimate the biological nature of lesion with great accuracy and therefore choose the best therapeutic procedure.

Diabetes Mellitus in Pancreatic Cancer: A Distinct Approach to Older Subjects with New-Onset Diabetes Mellitus.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is associated with a very poor prognosis, with near-identical incidence and mortality. According to the World Health Organization Globocan Database, the estimated number of new cases worldwide will rise by 70% between 2020 and 2040. There are no effective screening methods available so far, even for high-risk individuals. The prognosis of PDAC, even at its early stages, is still mostly unsatisfactory. Impaired glucose metabolism is present in about 3/4 of PDAC cases. METHODS: Available literature on pancreatic cancer and diabetes mellitus was reviewed using a PubMed database. Data from a national oncology registry (on PDAC) and information from a registry of healthcare providers (on diabetes mellitus and a number of abdominal ultrasound investigations) were obtained. RESULTS: New-onset diabetes mellitus in subjects older than 60 years should be an incentive for a prompt and detailed investigation to exclude PDAC. Type 2 diabetes mellitus, diabetes mellitus associated with chronic non-malignant diseases of the exocrine pancreas, and PDAC-associated type 3c diabetes mellitus are the most frequent types. Proper differentiation of particular types of new-onset diabetes mellitus is a starting point for a population-based program. An algorithm for subsequent steps of the workup was proposed. CONCLUSIONS: The structured, well-differentiated, and elaborately designed approach to the elderly with a new onset of diabetes mellitus could improve the current situation in diagnostics and subsequent poor outcomes of therapy of PDAC.

Wireless Monitoring of Gastrointestinal Transit Time, Intra-luminal pH, Pressure and Temperature in Experimental Pigs: A Pilot Study.

BACKGROUND: There is no single gold standard for investigation of gastrointestinal motility function. Wireless motility monitoring involves a novel concept which provides a complex information on gastrointestinal function (gastrointestinal transit time, intra-luminal pH, pressure and temperature). Gastrointestinal motility functions of experimental pigs are very similar to those of humans. That is why porcine studies have already provided suitable experimental models for several preclinical projects. AIMS: The aim of our study was to adopt methods of non-invasive wireless monitoring of gastrointestinal functions in experimental pigs. METHODS: Five experimental adult female pigs were enrolled into the study. Wireless motility capsules were delivered into the porcine stomach endoscopically. Gastrointestinal transit and intra-luminal conditions were recorded for five days. RESULTS: Records of animals provided good (3 pigs) or very good quality files (2 pigs). 31150 variables were evaluated. Mean time of the presence of capsules in the stomach was 926 ± 295 min, transfer of a capsule from the stomach into the duodenum lasted 5-34 min. Mean small intestinal transit time was 251 ± 43 min. Food intake was associated with an increase of gastric luminal temperature and a decrease of intra-gastric pressure. The highest intra-luminal pH was present in the ileum. The highest temperature and the lowest intra-luminal pressure were found in the colon. All data displayed a substantial inter-individual variability. CONCLUSIONS: This pilot study has proven that a long-term function monitoring of the gastrointestinal tract by means of wireless motility capsules in experimental pigs is feasible. However, both ketamine-based induction of general anaesthesia as well as long-lasting general anaesthesia (> 6 hours) should be avoided to prevent retention of a capsule in the porcine stomach.

Somatic Mutations in Exon 7 of the TP53 Gene in Index Colorectal Lesions Are Associated with the Early Occurrence of Metachronous Adenoma.

(1) Background: this prospective study was focused on detailed analysis of the mutation heterogeneity in colorectal lesions removed during baseline (index) colonoscopy to identify patients at high risk of early occurrence of metachronous adenomas. (2) Methods: a total of 120 patients after endoscopic therapy of advanced colorectal neoplasia size ≥10 mm (index lesion) with subsequent surveillance colonoscopy after 10-18 months were included. In total, 143 index lesions and 84 synchronous lesions in paraffin blocks were divided into up to 30 samples. In each of them, the detection of somatic mutations in 11 hot spot gene loci was performed. Statistical analysis to correlate the mutation profiles and the degree of heterogeneity of the lesions with the risk of metachronous adenoma occurrence was undertaken. (3) Results: mutation in exon 7 of the TP53 gene found in the index lesion significantly correlated with the early occurrence of metachronous adenoma (log-rank test p = 0.003, hazard ratio 2.73, 95% confidence interval 1.14-6.56). We did not find an association between the risk of metachronous adenomas and other markers monitored. (4) Conclusions: the findings of this study could lead to an adjustment of existing recommendations for surveillance colonoscopies in a specific group of patients with mutations in exon 7 of the TP53 gene in an index lesion, where a shortening of surveillance interval may be warranted.

Five-year analysis of the prevention of colorectal sporadic adenomatous polyps trial.

OBJECTIVES: Subjects in the Prevention of Colorectal Sporadic Adenomatous Polyps (PreSAP) trial (PRESAP/NCT00141193/www.clinicaltrials.gov) were studied to determine efficacy and safety at a year 5 assessment. METHODS: In this randomized, placebo-controlled, double-blind trial, 1,561 subjects with diagnosed colorectal adenomas removed within 3 months of the study's initiation were assessed after ~ 3 years on celecoxib followed by 2 years off. Studied in 107 primary and secondary care settings, subjects were stratified by cardioprotective aspirin use and randomized to receive orally 400 ng celecoxib (933 subjects) or placebo (628 subjects) once daily. Efficacy was measured by colonoscopy at years 1, 3, and 5, and safety was measured by investigators for the on-treatment period and collected by subject self-report over 2 years post-treatment. RESULTS: At year 5, the primary outcome measure was the rate of new adenomas measured cumulatively from baseline. This rate was statistically significantly lower in the celecoxib group (51.4%) than in the placebo group (57.5%; P<0.001). Similarly, the cumulative rate of new advanced adenomas was significantly lower in the celecoxib group (10.0%) than in the placebo group (13.8%; P=0.007). However, the year 5 interval measure, which was not cumulative and did not take the rates of previous years into account, showed that after 2 years off treatment, the celecoxib group (27.0%) was 1.66 times more likely to have new adenomas than the placebo group (16.3%; P<0.0001). Similarly, the percentage of patients with new advanced adenomas was significantly higher in the celecoxib group (5.0%) than in the placebo group (3.8%) (P=0.0072). The evaluation of safety from baseline through year 5 indicated that the risks of serious cardiac disorders (relative risk (RR) 1.66; 95% confidence interval (CI) 1.01-2.73), selected renal/hypertension events (RR 1.35; 95% CI 1.09-1.68), and general vascular (RR 1.34; 95% CI 1.08-1.68) and cardiac disorders (RR 1.59; 95% CI 1.12-2.26) were higher in those taking celecoxib than in those on placebo. CONCLUSIONS: The year 5 cumulative measures of the incidence of new and advanced adenomas were significantly lower in the celecoxib group than in the placebo group, but the year 5 interval rates of these measures were significantly lower in the placebo group than the celecoxib group, perhaps suggesting a release of cyclooxygenase-2 inhibition. Consistent with what has been previously reported, increased risk of renal/hypertension events and cardiac disorders associated with celecoxib therapy mandates caution in patient selection.

Training on an ex vivo animal model improves endoscopic skills: a randomized, single-blind study.

BACKGROUND: Animal models are used for training of different endoscopic procedures. Whether this really improves endoscopic skills remains controversial. OBJECTIVE: To assess the effectiveness of training by using an ex vivo animal gastric model on the performance of two therapeutic procedures-hemostasis and treatment of perforation. DESIGN: A randomized, single-blind study. SETTING: An experimental endoscopy center in a university hospital. PARTICIPANTS: Thirty-one gastroenterology fellows with comparable endoscopic experience. METHODS: Participants were randomized into two groups: with (T, n = 16) and without (S, n = 15) training. All fellows continued with standard endoscopic practice. Baseline skills were assessed at enrollment. All physicians in group T underwent 2 full days of a hands-on course over a 3-month period, in addition to their standard endoscopic practice. Both groups then underwent a blinded, final evaluation. Endoscopic skills were scored from 1 (best) to 5 (poorest) by two expert, blinded tutors. Outcomes of clinical hemostatic procedures also were analyzed. MAIN OUTCOME MEASUREMENTS: Successful hemostasis and successful perforation closure. RESULTS: Thirty physicians completed the study. Hemostasis results (n = 15): The number of physicians who carried out a successful hemostasis procedure increased significantly in the group with training (27% vs 73%; P = .009) but did not change in the group without training (20% vs 20%). The mean scores of injection and clipping technique improved significantly only after training. The number of clips used decreased significantly only in the group with training; the time of clipping did not change significantly in either group. Perforation results (n = 15): The number of physicians with a successful and complete perforation closure increased nearly significantly in the group with training (40% vs 73%, P = .06) as opposed to the group without training (27% vs 47%; P = .27). The procedure time decreased significantly in the group with training only. In clinical practice, fellows in group T had a significantly higher success rate with respect to hemostatic procedures (83.2%, range 67-100 vs 63.6%, range 25-100; P = .0447). The majority of participants (93%) agreed that such courses should be compulsory in gastroenterological credentials. LIMITATIONS: A retrospective analysis of clinical outcomes. Clinical outcome data were based on self-reporting of the participants. CONCLUSION: Hands-on training by using an animal ex vivo model improves endoscopic skills in both hemostasis and perforation closure. In clinical practice, the training improves the outcome of hemostatic procedures.

Comparison of Four Bowel Cleansing Agents for Colonoscopy and the Factors Affecting their Efficacy. A Prospective, Randomized Study.

BACKGROUND AND AIMS: Adequate bowel preparation is essential for successful and effective colonoscopy. Several types of cleansing agents are currently available including low-volume solutions. The aim of this study was to compare the efficacy of four different bowel cleansing agents. METHODS: A single-center, prospective, randomized, and single-blind study was performed. Consecutive patients referred for colonoscopy were enrolled and randomized into one of the following types of laxatives: polyethylenglycol 4L (PEG), oral sulfate solution (OSS), 2L polyethylenglycol + ascorbate (2L-PEG/Asc), or magnesium citrate + sodium picosulfate (MCSP). The primary outcome was quality of bowel cleansing evaluated according to the Boston Bowel Preparation Scale (BBPS). Secondary outcomes were polyp detection rate (PDR) and tolerability. RESULTS: Final analysis was performed on 431 patients. The number of patients with adequate bowel preparation (BBPS total scores ≥6 and sub scores ≥2 in each segment) was not significantly different throughout all groups (95.4% PEG; 94.6% OSS; 96.3% 2L-PEG/Asc; 96.2% MCSP; p=0.955). Excellent bowel preparation (BBPS total scores ≥ 8) was associated with younger age (p=0.007). The groups did not have significantly different PDRs (49.5% PEG; 49.1% OSS; 38% 2L-PEG/Asc; 40.4% MCSP; p=0.201). The strongest predictors of pathology identification were age and male gender. The best-tolerated solution was MCSP (palatability: p<0.001; nausea: p=0.024).

"A surviving myth"--corticosteroids are still considered ulcerogenic by a majority of physicians.

OBJECTIVE: Evidence does not support an association between systemic corticosteroid use and the development of peptic ulcer disease (PUD) and prophylactic anti-ulcer therapy is not routinely indicated. The aim was to find out the opinion of physicians in the Czech Republic on corticosteroid-induced ulcers. MATERIALS AND METHODS: A questionnaire-based study targeting 360 physicians of different specialties (100 from Gastroenterology, 100 from General Practice, 80 from Pneumology/Immunology, and 80 from Neurology/Neurosurgery). RESULTS: Eighty-two percent of the physicians considered corticosteroids ulcerogenic, 7.5% of the responders considered them ulcerogenic only in patients with a family history of PUD, and 10.3% of the physicians considered corticosteroids non-ulcerogenic. Seventy-five percent of the responders would administer concomitant antisecretory treatment. Sixty-seven percent of the physicians thought that PUD was a frequent complication of corticosteroid therapy. If the ulcerogenic potential of ibuprofen, diclofenac, and prednisone was a subject of the physicians' judgment, a majority (40.5%) considered prednisone to be the most ulcerogenic substance. Thirty percent of gastroenterologists (vs. 1.9% of others; p < 0.001) did not consider corticosteroids to be ulcerogenic; 27.4% (vs. 4.3%; p < 0.01) would not administer an antisecretory prophylaxis routinely. CONCLUSIONS: Although there is no evidence showing an association between PUD and the use of corticosteroids, a majority of physicians consider corticosteroids gastrotoxic. This applies, to a lesser extent, to gastroenterologists. Action should be taken to explode the myth about the gastrotoxicity of corticosteroids and to minimize useless expenses on concomitant prophylaxis.

Comparison of Native Aspirates and Cytological Smears Obtained by EUS-Guided Biopsies for Effective DNA/RNA Marker Testing in Pancreatic Cancer.

We compare two types of pancreatic carcinoma samples obtained by EUS-guided fine needle biopsy (EUS-FNB) in terms of the success rates and clinical validity of analysis of two most commonly investigated DNA/RNA pancreatic cancer markers, KRAS mutations and miR-21 expression. 118 patients with pancreatic ductal adenocarcinoma underwent EUS-FNB. The collected sample was divided, one part was stored in a stabilizing solution as native aspirate (EUS-FNA) and second part was processed into the cytological smear (EUS-FNC). DNA/RNA extraction was followed by analysis of KRAS mutations and miR-21 expression. For both sample types, the yields of DNA/RNA extraction and success rates of KRAS mutation and miRNA expression were evaluated. Finally, the resulting KRAS mutation frequency and miR-21 prognostic role were compared to literature data from tissue resections. The overall amount of isolated DNA/RNA from EUS-FNC was lower compared to the EUS-FNA, average yield 10 ng vs 147 ng for DNA and average yield 164 vs. 642 ng for RNA, but the success rates for KRAS and miR-21 analysis was 100% for both sample types. The KRAS-mutant detection frequency in EUS-FNC was 12% higher than in EUS-FNA (90 vs 78%). The prognostic role of miR-21 was confirmed in EUS-FNC (p = 0.02), but did not reach statistical significance in EUS-FNA (p = 0.06). Although both types of EUS-FNB samples are suitable for DNA/RNA extraction and subsequent DNA mutation and miRNA expression analysis, reliable results with clinical validity were only obtained for EUS-FNC.

The conversion factor for predicting adenoma detection rate from polyp detection rate varies according to colonoscopy indication and patient sex.

The adenoma detection rate (ADR) is the primary quality indicator for colonoscopies. The polyp detection rate (PDR) is available from administrative data and does not depend on histology verification. The correlation between PDR and ADR and the ADR/PDR conversion factor in preventive colonoscopies were evaluated. In the prospective study, asymptomatic individuals aged 45-75 years with preventive colonoscopy in 2012-2016 were included. Spearman's correlation coefficient was used to assess PDR/ADR for each endoscopist. Conversion factor predicting ADR from PDR was obtained by linear regression and subsequently compared with adenoma to polyp detection rate quotient. One thousand six hundred fourteen preventive colonoscopies performed by 16 endoscopists in 8 screening colonoscopy centres in the Czech Republic were analysed. Correlation between PDR and ADR in all preventive colonoscopies was high and statistically significant (Rs 0.82; P < 0.001). There was a strong correlation between PDR and ADR in men (Rs 0.74; P = 0.002) and in screening colonoscopies (Rs 0.85; P < 0.001). The conversion factor to convert ADR from PDR was 0.72 in all preventive colonoscopies, 0.76 in FOBT+ colonoscopies and 0.67 in screening colonoscopies. ADR may be replaced by PDR in the assessment of colonoscopy quality. The value of the conversion factor varies according to colonoscopy indication and gender of examined individuals; in this Czech study, it was 0.72 in all preventive colonoscopies. The minimum requested ADR of 25 % corresponds to a PDR of 35 %, when converted with the appropriate conversion factor.