Sample preference for colorectal cancer screening tests: Blood or stool?

Objective: Despite the high prevalence of CRC and the proven benefits of faecal sampling tests, participation rates in CRC screening are suboptimal. Literature has identified a number of barriers to participation, including faecal aversion. Emerging test technologies suggest blood-based molecular markers might provide an alternative, more acceptable option, for CRC screening tests. We aim to determine preference for blood compared to faeces as the sample for the screening test. Methods: A survey was mailed to 956 South Australians aged 50 to 74 years. Data were collected on sample preference, demographic variables, and ratings of screening test convenience and comfort. Results: The survey yielded a 43% response rate. The majority of participants preferred to provide a blood sample (78% v 22%, p < 0.001). Women were more likely to prefer blood than men (82% vs 74%, p = 0.05). Sample experience influenced preferences, with a significantly higher preference for faeces among participants with experience in faecal sampling (27% vs 17% with no experience, p < 0.05). Participants who preferred to provide a faecal sample rated it significantly more convenient (p < 0.001), more comfortable (p < 0.001), and more acceptable (p < 0.001) than those who preferred blood sampling. Conclusions: Survey participants overwhelmingly indicate a preference for the idea of a blood sample over a faecal sample for CRC screening. Preference was influenced by gender, experience with sampling method and the individual’s perception of sampling convenience, sampling comfort and sample acceptability. Our results suggest population participation rates are likely to improve with blood-based screening tests.

Early colorectal cancer screening–no time to lose

In this editorial,we comment on the article entitled“Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?”by Agatsuma et al.Colorectal cancer(CRC)is emerging as an important health issue as its incidence continues to rise globally,adversely affecting the quality of life.Although the public has become more aware of CRC prevention,most patients lack screening awareness.Some poor lifestyle practices can lead to CRC and symptoms can appear in the early stages of CRC.However,due to the lack of awareness of the disease,most of the CRC patients are diagnosed already at an advanced stage and have a poor prognosis.

Systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations

AIM To summarize and compare worldwide colorectal cancer(CRC) screening recommendations in order to identify similarities and disparities.METHODS A systematic literature search was performed using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge identifying all average-risk CRC screening guideline publications within the last ten years and/or position statements published in the last 2 years. In addition, a hand-search of the webpages of National Gastroenterology Society websites, the National Guideline Clearinghouse, the BMJ Clinical Evidence website,Google and Google Scholar was performed. RESULTS Fifteen guidelines were identified. Six guidelines were published in North America, four in Europe, four in Asia and one from the World Gastroenterology Organization. The majority of guidelines recommend screening average-risk individuals between ages 50 and 75 using colonoscopy(every 10 years), or flexible sigmoidoscopy(FS, every 5 years) or fecal occult blood test(FOBT, mainly the Fecal Immunochemical Test, annually or biennially). Disparities throughout the different guidelines are found relating to the use of colonoscopy, rank order between test, screening intervals and optimal age ranges for screening. CONCLUSION Average risk individuals between 50 and 75 years should undergo CRC screening. Recommendations for optimal surveillance intervals, preferred tests/test cascade as well as the optimal timing when to start and stop screening differ regionally and should be considered for clinical decision making. Furthermore, local resource availability and patient preferences are important to increase CRC screening uptake, as any screening is better than none.

Performance value of high risk factors in colorectal cancer screening in China

AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation.Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.RESULTS:The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia.The iFOBT had the highest sensitivity,lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas.A history of chronic cholecystitis or cholecystectomy,chronic appendicitis or appendectomy,and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas.The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for nonadenomatous polyps.A history of chronic appendicitis or appendectomy,chronic constipation,chronic diarrhea,mucous and bloody stool,CRC in first degree relatives,malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps.Except for a history of malignant tumor in screening for non-adenomatous polyps,the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.CONCLUSION:The iFOBT may be the best marker for screening for advanced neoplasias and adenomas.Some unique high risk factors may play an important role in CRC screening in China.

New strategies for colorectal cancer screening

Colorectal cancer (CRC) is still one of the leading causes of cancer-related death in Western countries, despite major improvements in its treatment. The dramatically high social and economic impact of CRC on human health makes the identification of a reliable screening tool of paramount importance. Current screening methods, such as the fecal occult blood test and colonoscopy do not adequately meet the ideal requisites of a screening test because, even if they are effective, they are limited first by too low specificity and sensitivity, or second by high invasiveness, costs and risk. Nowadays extended efforts are made by researchers to look for more reliable and effective screening tests based on a systems biology approach, using biological samples easily available, such as urine, breath, serum and feces. The effectiveness and reliability of several new attempts to screen these patients by non-invasive analysis of their biological samples using genomic (genetic and epigenetic alteration), transcriptomic (miRNA), proteomic (cancer-related antigens, new antibodies against tumor-associated antigens, mutated proteins) and metabolomic (volatile organic metabolites) methods are discussed in this review. Among the most interesting new screening tools, fecal fluorescent long-DNA, fecal miRNA and metabolomic evaluation in breath and/ or serum seem to be most promising.

Supply and quality of colonoscopy according to the characteristics of gastroenterologists in the French population-based colorectalcancer screening program

BACKGROUND Since its complete roll-out in 2009,the French colorectal cancer screening program(CRCSP)experienced 3 major constraints[use of a less efficient Guaiac-test(gFOBT),stopping the supply of Fecal-Immunochemical-Test kits(FIT),and suspension of the program due to the coronavirus disease 2019(COVID-19)]affecting its effectiveness.AIM To describe the impact of the constraints in terms of changes in the quality of screeningcolonoscopy(Quali-Colo).METHODS This retrospective cohort study included screening-colonoscopies performed by gastroenterologists between Jan-2010 and Dec-2020 in people aged 50-74 living in Ile-de-France(France).The changes in Quali-colo(Proportion of colonoscopies performed beyond 7 mo(Colo_7 mo),Frequency of serious adverse events(SAE)and Colonoscopy detection rate)were described in a cohort of Gastroenterologists who performed at least one colonoscopy over each of the four periods defined according to the chronology of the constraints[gFOBT:Normal progress of the CRCSP using gFOBT(2010-2014);FIT:Normal progress of the CRCSP using FIT(2015-2018);STOP-FIT:Year(2019)during which the CRCSP experienced the cessation of the supply of test kits;COVID:Program suspension due to the COVID-19 health crisis(2020)].The link between each dependent variable(Colo_7 mo;SAE occurrence,neoplasm detection rate)and the predictive factors was analyzed in a two-level multivariate hierarchical model.RESULTS The 533 gastroenterologists(cohort)achieved 21509 screening colonoscopies over gFOBT period,38352 over FIT,7342 over STOP-FIT and 7995 over COVID period.The frequency of SAE did not change between periods(gFOBT:0.3%;FIT:0.3%;STOP-FIT:0.3%;and COVID:0.2%;P=0.10).The risk of Colo_7 mo doubled between FIT[adjusted odds ratio(aOR):1.2(1.1;1.2)]and STOPFIT[aOR:2.4(2.1;2.6)];then,decreased by 40%between STOP-FIT and COVID[aOR:2.0(1.8;2.2)].Regardless of the period,this Colo_7 mo’s risk was twice as high for screening colonoscopy performed in a public hospital[aOR:2.1(1.3;3.6)]compared to screening-colonoscopy performed in a private clinic.The neoplasm detection,which increased by 60%between gFOBT and FIT[aOR:1.6(1.5;1.7)],decreased by 40%between FIT and COVID[aOR:1.1(1.0;1.3)].CONCLUSION The constraints likely affected the time-to-colonoscopy as well as the colonoscopy detection rate without impacting the SAE’s occurrence,highlighting the need for a respectable reference time-tocolonoscopy in CRCSP.

CT colonography after incomplete colonoscopy in subjects with positive faecal occult blood test

AIM： To report our experience with computed tomography colonography （CTC） systematically performed in subjects with positive faecal occult blood test （FOBT） and an incomplete colonoscopy in the setting of a population-based screening for colorectal cancer （CRC）. METHODS： From April 2006 to April 2007, 43 290 individuals （age range 50-70） who adhered to the regional screening program for the prevention of CRC underwent immunochemical FOBT. FOBT was positive in 1882 subjects （4.3%）. 1463 （77.7%） of these subjects underwent colonoscopy, 903 performed in a single center. Of 903 colonoscopies 65 （7.2%） were incomplete. Forty-two of these subjects underwent CTC. CTC was performed with a 16-MDCT scanner after standard bowel prep （polyethyleneglycole） in both supine and prone position. Subjects whose CTC showed polyps or masses were referred to the endoscopist for repeat colonoscopy under sedation or underwent surgery. Perlesion and per-segment positive predictive values （PPV） were calculated. RESULTS： Twenty-one （50%） of 42 CTCs showed polyps or masses. Fifty-five of these subjects underwent a repeat colonoscopy, whereas 2 subjects underwent surgery for colonic masses of indeterminate nature. Four subjects refused further examinations. CTC correctly identified 2 colonic masses and 20 polyps. PPV for masses or polyps greater than 9 mm was of 87.5%. Per-lesion and per-segment PPV were, respectively, 83.3% and 83.3% for polyps greater or equal to 10 mm, and 77.8% and 85.7% for polyps of 6-9 mm. CONCLUSION： In the context of a screening program for CRC based on FOBT, CTC shows high per-segment and per-lesion PPV for colonic masses and polyps greater than 9 mm. Therefore, CTC has the potential to become a useful technique for evaluation of the non visualized part of the colon after incomplete colonoscopy.

To scope or not-the challenges of managing patients with positive fecal occult blood test after recent colonoscopy

BACKGROUND Colorectal cancer(CRC) is a major health problem. There is minimal consensus of the appropriate approach to manage patients with positive immunochemical fecal occult blood test(iFOBT), following a recent colonoscopy.AIM To determine the prevalence of advanced neoplasia in patients with a positive iFOBT after a recent colonoscopy, and clinical and endoscopic predictors for advanced neoplasia.METHODS The study recruited i FOBT positive patients who underwent colonoscopy between July 2015 to March 2020. Data collected included demographics, clinical characteristics, previous and current colonoscopy findings. Primary outcome was the prevalence of CRC and advanced neoplasia in a patient with positive iFOBT and previous colonoscopy. Secondary outcomes included identifying any clinical and endoscopic predictors for advanced neoplasia.RESULTS The study included 1051 patients(male 53.6%;median age 63). Forty-two(4.0%) patients were diagnosed with CRC, 513(48.8%) with adenoma/sessile serrated lesion(A-SSL) and 257(24.5%) with advanced A-SSL(AA-SSL). A previous colonoscopy had been performed in 319(30.3%). In this cohort, four(1.3%) were diagnosed with CRC, 146(45.8%) with A-SSL and 56(17.6%) with AA-SSL. Among those who had a colonoscopy within 4 years, none had CRC and 7 had AA-SSL. Of the 732 patients with no prior colonoscopy, there were 38 CRCs(5.2%). Independent predictors for advanced neoplasia were male [odds ratio(OR) = 1.80;95% confidence interval(CI): 1.35-2.40;P < 0.001), age(OR = 1.04;95%CI: 1.02-1.06;P < 0.001) and no previous colonoscopy(OR = 2.07;95%CI: 1.49-2.87;P < 0.001).CONCLUSION A previous colonoscopy, irrespective of its result, was associated with low prevalence of advanced neoplasia, and if performed within four years of a positive iFOBT result, was protective against CRC.

Colorectal cancer screening: An updated review of the available options

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. However, colon cancer incidence and mortality is declining over the past decade owing to adoption of effective screening programs. Nevertheless, in some parts of the world, CRC incidence and mortality remain on the rise, likely due to factors including “westernized” diet, lifestyle, and lack of health-care infrastructure and resources. Participation and adherence to different national screening programs remain obstacles limiting the achievement of screening goals. Different modalities are available ranging from stool based tests to radiology and endoscopy with varying sensitivity and specificity. However, the availability of these tests is limited to areas with high economic resources. Recently, FDA approved a blood-based test (Epi procolon®) for CRC screening. This blood based test may serve to increase the participation and adherence rates. Hence, leading to increase in colon cancer detection and prevention. This article will discuss various CRC screening tests with a particular focus on the data regarding the new approved blood test. Finally, we will propose an algorithm for a simple cost-effective CRC screening program.

Colorectal cancer population screening programs worldwide in 2016: An update

Colorectal cancer(CRC)is the third most commonly diagnosed cancer in the world.The incidence and mortality show wide geographical variations.Screening is recommended to reduce both incidence and mortality.However,there are significant differences among studies in implementation strategies and detection.This review aimed to present the results and strategies of different screening programs worldwide.We reviewed the literature on national and international screening programs published in Pub Med,on web pages,and in clinical guidelines.CRC Screening programs are currently underway in most European countries,Canada,specific regions in North and South America,Asia,and Oceania.The most extensive screening strategies were based on fecal occult blood testing,and more recently,the fecal immunochemical test(FIT).Participation in screening has varied greatly among different programs.The Netherlands showed the highest participation rate(68.2%)and some areas of Canada showed the lowest(16%).Participation rates were highest among women and in programs that used the FIT test.Men exhibited the greatest number of positive results.The FIT test has been the most widely used screening program worldwide.The advent of this test has increased participation rates and the detection of positive results.

Barriers to colorectal cancer screening:A case-control study

AIM:To investigate barriers to colorectal cancer(CRC) screening in a community population.METHODS:We conducted a community-based case-control study in an urban Chinese population by questionnaire.Cases were selected from those completing both a fecal occult blood test(FOBT) case and colonoscopy in a CRC screening program in 2004.Control groups were matched by gender, age group and community.Control 1 included those having a positive FOBT but refusing a colonoscopy.Control 2 included those who refused both an FOBT and colonoscopy.RESULTS:The impact of occupation on willingness to attend a colorectal screening program differed by gender.P for heterogeneity was 0.009 for case vs control group 1, 0.01 for case versus control group 2, and 0.80 for control group 1 vs 2.Poor awareness of CRC and its screening program, characteristics of screening tests, and lack of time affected the screening rate.Financial support, fear of pain and bowel preparation were barriers to a colonoscopy as a screening test.Eighty-two percent of control group 1 and 87.1% of control group 2 were willing attend if the colonoscopy was free, but only 56.3% and 53.1%, respectively, if it was self-paid.Multivariate odds ratios for case vs control group 1 were 0.10 among those unwilling to attend a free colonoscopy and 0.50 among those unwilling to attend a self-paid colonoscopy.CONCLUSION:Raising the public awareness of CRC and its screening, integrating CRC screening into the health care system, and using a painless colonoscopy would increase its screening rate.

Colorectal cancer screening:20 years of development and recent progress

Colorectal cancer(CRC)is the second most common cancer in Europe and its incidence is steadily increasing.This trend could be reversed through timely secondary prevention(screening).In the last twenty years,CRC screening programs across Europe have experienced considerable improvements(fecal occult blood testing;transition from opportunistic to population based program settings).The Czech Republic is a typical example of a country with a long history of nationwide CRC screening programs in the face of very high CRC incidence and mortality rates.Each year,approximately 8000 people are diagnosed with CRC and some 4000 die from this malignancy.Twenty years ago,the first pilot studies on CRC screening led to the introduction of the opportunistic Czech National Colorectal Cancer Screening Program in 2000.Originally,this program was based on the guaiac fecal occult blood test(FOBT)offered by general practitioners,followed by colonoscopy in cases of FOBT positivity.The program has continuously evolved,namely with the implementation of immunochemical FOBTs and screening colonoscopy,as well as the involvement of gynecologists.Since the establishment of the Czech CRC Screening Registry in 2006,2405850 FOBTs have been performed and 104565 preventive colonoscopies recorded within the screening program.The overall program expanded to cover 25.0%of the target population by 2011.However,stagnation in the annual number of performed FOBTs lately has led to switching to the option of a population-based program with personal invitation,which is currently being prepared.

Colorectal cancer screening in Europe

Colorectal cancer(CRC)is the second most frequent malignant disease in Europe.Every year,412 000people are diagnosed with this condition,and 207 000patients die of it.In 2003,recommendations forscreening programs were issued by the Council of the European Union(EU),and these currently serve as thebasis for the preparation of European guidelines forCRC screening.The manner in which CRC screening iscarried out varies significantly from country to countrywithin the EU,both in terms of organization and thescreening test chosen.A screening program of onesort or another has been implemented in 19 of 27 EUcountries.The most frequently applied method is testing stool for occult bleeding(fecal occult blood test,FOBT).In recent years,a screening colonoscopy hasbeen introduced,either as the only method(Poland)orthe method of choice(Germany,Czech Republic).

Colorectal cancer screening

Colorectal cancer is a major public health burden worldwide. There is clear-cut evidence that screening will reduce colorectal cancer mortality and the only contentious issue is which screening tool to use. Most evidence points towards screening with fecal occult blood testing. The immunochemical fecal occult blood tests have a higher sensitivity than the guaiac-based tests. Zn addition, their automation and haemoglobin quantification allows a threshold for colonoscopy to be selected that can be accommodated within individual health care systems.

Familial colorectal cancer screening: When and what to do?

Colorectal cancer(CRC) is the third leading cause of death worldwide and represents a clinical challenge.Family members of patients affected by CRC have an increased risk of CRC development.In these individuals,screening is strongly recommended and should be started earlier than in the population with average risk,in order to detect neoplastic precursors,such as adenoma,advanced adenoma,and nonpolypoid adenomatous lesions of the colon.Fecal occult blood test(FOBT) is a non invasive,widespread screening method that can reduce CRC-related mortality.Sigmoidoscopy,alone or in addition to FOBT,represents another screening strategy that reduces CRC mortality.Colonoscopy is the best choice for screening highrisk populations,as it allows simultaneous detection and removal of preneoplastic lesions.The choice of test depends on local health policy and varies among countries.

Viewpoints of the target population regarding barriers and facilitators of colorectal cancer screening in the Czech Republic

BACKGROUND Public awareness of colorectal cancer(CRC) and uptake of CRC screening remain challenges. The viewpoints of the target population(asymptomatic individuals older than 50) regarding CRC screening information sources and the reasons for and against participation in CRC screening are not well known in the Czech Republic. This study aimed to acquire independent opinions from the target population independently on the health system.AIM To investigate the viewpoints of the target population regarding the source of information for and barriers and facilitators of CRC screening.METHODS A survey among relatives(aged 50 and older) of university students was conducted. Participants answered a questionnaire about sources of awareness regarding CRC screening, reasons for and against participation, and suggestions for improvements in CRC screening. The effect of certain variables on participation in CRC screening was analyzed.RESULTS Of 498 participants, 478(96%) respondents had some information about CRC screening and 375(75.3%) had participated in a CRC screening test. General practitioners(GPs)(n = 319, 64.1%) and traditional media(n = 166, 33.3%) were the most common information sources regarding CRC screening. A lack of interest or time and a fear of colonoscopy or positive results were reported as reasons for non-participation. Individuals aged > 60 years [adjusted odds ratio(aOR) = 2.30, 95% confidence interval(CI)(1.42-3.71), P = 0.001], females(aOR =1.95, 95%CI(1.26-3.01) P = 0.003), and relatives of CRC patients(aOR = 4.17,95%CI(1.82-9.58) P = 0.001) were more likely to participate in screening.Information regarding screening provided by physicians-GPs:(aOR = 8.11,95%CI(4.90-13.41), P < 0.001) and other specialists(aOR = 4.19, 95%CI(1.87-9.38),P = 0.001) increased participation in screening. Respondents suggested that providing better explanations regarding screening procedures and equipment for stool capturing could improve CRC screening uptake.CONCLUSION GPs and other specialists play crucial roles in the successful uptake of CRC screening. Reduction of the fear of colonoscopy and simple equipment for stool sampling might assist in improving the uptake of CRC screening.

Perspectives of colorectal cancer screening in Germany 2009

Adequate screening methods can decrease colorectal cancer(CRC) mortality.The guaiac test for fecal occultblood(FOBT) is part of the German CRC Screening Program since 1970 and has evidence level Ia.In randomized multicenter-studies FOBT has an average sensitivity of 24% and decreases CRC mortality up to 30%.Immunological tests for human haemoglobin(iFOBT) show better performance characteristics than guaiac FOBT,with augmented sensitivity and specificity.However,the single tests show wide differences in diagnostic performance and iFOBT is not yet covered by insurance companies although it should replace the guaiac test for CRC screening.Visual colonoscopy,which was introduced to the German National Cancer Screening Program in 2002,is the gold standard for the diagnosis of colorectal neoplasia.From 2003 to 2007 more than 2.8 million examinations have been documented in Germany.The prevalence of adenomas is around 20% and of CRC about 0.7% to 1.0% of the screenings.Seventy percent of the carcinomas detected during screening are in an early stage(UICCⅠand Ⅱ).Furthermore,screening colonoscopy is a cost saving procedure with a low complication rate(0.25% overall).Insurance companies save 216€ for each screening colonoscopy mainly by prevention of neoplasia due to polypectomy.In Germany,virtual colonography by computed tomography(CT) or magnetic resonance imaging still lacks standardization of the hard and software.In experienced centres the sensitivity for CRC and large polyps of CT colonography is comparable to colonoscopy but in meta-analyses the ranking is lower.New technologies like computer-aided colonoscopies with sheath or double balloon techniques are coming up as well as capsule colonoscopy,which sensitivity for large polyps is about 70%.Advised by his physician,the patient can choose his most acceptable examination method from this whole set of screening tools.

Results of National Colorectal Cancer Screening Program in Croatia(2007-2011)

AIM:To study the epidemiologic indicators of uptake and characteristic colonoscopic findings in the Croatian National Colorectal Cancer Screening Program.METHODS:Colorectal cancer(CRC) was the second leading cause of cancer mortality in men(n = 1063,49.77/100 000),as well as women(n = 803,34.89/100 000) in Croatia in 2009.The Croatian National CRC Screening Program was established by the Ministry of Health and Social Welfare,and its implementation started in September,2007.The coordinators were recruited in each county institute of public health with an obligation to provide fecal occult blood testing(FOBT) to the participants,followed by colonoscopy in all positive cases.The FOBT was performed by hypersensitive guaiac-based Hemognost card test(Biognost,Zagreb).The test and short questionnaire were delivered to the home addresses of all citizens aged 50-74 years consecutively during a 3-year period.Each participant was required to complete the questionnaire and send it together with the stool specimen on three test cards back to the institute for further analysis.About 4% FOBT positive cases are expected in normal risk populations.A descriptive analysis was performed.RESULTS:A total of 1 056 694 individuals(born between 1933-1945 and 1952-1957) were invited to screening by the end of September 2011.In total,210 239(19.9%) persons returned the envelope with a completed questionnaire,and 181 102 of them returned it with a correctly placed stool specimen on FOBT cards.Until now,12 477(6.9%),FOBT-positive patients have been found,which is at the upper limit of the expected values in European Guidelines for Quality Assurance in CRC Screening and Diagnosis [European Union(EU) Guidelines].Colonoscopy was performed in 8541 cases(uptake 66%).Screening has identified CRC in 472 patients(5.5% of colonoscopied,3.8% of FOBT-positive,and 0.26% of all screened individuals).This is also in the expected range according to EU Guidelines.Polyps were found and removed in 3329(39% of colonoscopied) patients.The largest number of polyps were found in the left half of the colon:64%(19%,37% and 8% in the rectum,sigma,and descendens,respectively).The other 36% were detected in the proximal part(17% in the transverse colon and 19% in ceco-ascending colon).Small polyps in the rectum(5-10 mm in diameter),sigmoid and descending colon were histologically found to be tubular adenomas in 60% of cases,with a low degree of dysplasia,and 40% were classified as hyperplastic.Polyps of this size in the transverse or ceco-ascending colon in almost 20% had a histologically villous component,but still had a low degree of dysplasia.Polyps sized 10-20 mm in diameter were in 43% cases tubulovillous,and among them,32% had areas with a high degree of dysplasia,especially those polyps in the cecoascending or transverse part.The characteristics of the Croatian CRC Screening National Program in the first 3 years were as follows:relatively low percentage of returned FOBT,higher number of FOBT-positive persons but still in the range for population-based programs,and higher number of pathologic findings(polyps and cancers).CONCLUSION:These results suggest a need for intervention strategies that include organizational changes and educational activities to improve awareness of CRC screening usefulness and increase participation rates.

具核梭杆菌在结直肠癌筛查中的应用价值

目的探讨具核梭杆菌(Fn)在结直肠癌筛查中的临床价值。方法前瞻性纳入于2022年7月至2023年12月期间在首都医科大学附属北京友谊医院行结肠镜检查者。于结肠镜检查前3 d内留取粪便样本,采用定量聚合酶链反应(qPCR)法检测粪便中菌群Fn的相对丰度,同时行粪便隐血试验(FOBT)。采用受试者操作特征(ROC)曲线评估Fn对结直肠癌的诊断效能。结果共纳入271例受试者,其中诊断结直肠癌58例(21.40%)。结直肠癌组患者粪便中的Fn相对丰度显著高于非结直肠癌组[6.602(3.716,8.997)vs.1.665(0.593,4.752)],差异有统计学意义(P<0.05)。Fn诊断结直肠癌的曲线下面积(AUC)为0.750(95%CI:0.680~0.820,P<0.05),对应敏感度、特异度和阴性预测值分别为0.724、0.742和0.908。在FOBT结果阴性者中,Fn诊断结直肠癌的敏感度、特异度和阴性预测值分别为0.714、0.730和0.983。Fn联合FOBT诊断结直肠癌的AUC为0.894(95%CI:0.848~0.940,P<0.05),对应敏感度、特异度和阴性预测值分别为0.897、0.765和0.964,诊断效能显著优于单独检测Fn(P<0.05)。结论粪便Fn在结直肠癌筛查中具有较高的敏感性、特异性和阴性预测值,与FOBT联合应用可进一步提升结直肠癌检出率。因此,粪便Fn是结直肠癌筛查有价值的无创生物标志物,可有效避免FOBT阴性者中结直肠癌的漏诊。粪便Fn丰度升高者应尽快行结肠镜检查,若Fn与FOBT均阴性,则可基本排除结直肠癌。

粪便隐血试验在体检人群中对大肠癌早期筛查的价值

目的研究免疫化学法粪便隐血试验(FIT)在体检人群中大肠癌早期筛查的应用价值。方法选取2017年9月至2020年9月该院体检中心健康体检人群,收集行FIT患者的基本资料,根据内镜下有无新生物、FIT检测值、新生物直径及位置进行分组;采用单样本K-S检验、Kruskal-Wallis H检查、χ^(2)检验进行组间统计分析,Spearman法分析双变量关系,多重线性回归模型分析性别、年龄及新生物病理类型、位置、直径、个数对FIT的预测价值。结果315例患者满足FIT>100 ng/mL并完成肠镜检查,包括大肠癌(腺癌)19例,腺瘤性息肉94例,增生性息肉59例,正常及其他疾病143例,男性大肠癌发病比率高于女性(χ^(2)=15.74,P<0.01)。FIT检测值平均中位水平:肿瘤组>腺瘤性息肉组>无新生物组>增生性息肉组,除无新生物组与增生性息肉组之间差异无统计学意义(P=0.206),其余各组间差异均有统计学意义(P<0.05)。随着FIT检测值的增加,肠镜正常和增生性息肉的占比下降,腺瘤和腺癌的占比升高(P<0.01)。新生物直径中位水平:肿瘤组>腺瘤性息肉组>增生性息肉组(P<0.01)。随着新生物直径的增加,增生性息肉百分比下降,肿瘤所占比例增加(P<0.01)。左半结肠发病率显著高于结肠其他部位(P<0.01)。双变量相关分析显示,FIT检测值与新生物病理类型、直径、个数呈正相关(r=0.291、0.591、0.354,P<0.01)。多重线性回归分析显示新生物病理类型、直径、个数是影响FIT检测值的独立影响因素,线性方程式为Y=-584.875+319.315×1+264.241×2+109.942×3(×1、×2、×3分别代表新生物病理类型、直径、个数),P<0.01。结论FIT能够有效应用于大肠癌的早期筛查,其检测值高低与肠道新生物癌变程度、直径呈正相关,男性患者、左半结肠病变、大直径新生物易发生癌变。