Effectiveness of colonoscopy,immune fecal occult blood testing,and risk-graded screening strategies in colorectal cancer screening

BACKGROUND Colorectal cancer(CRC)is one of the most common malignant tumors,and early screening is crucial to improving the survival rate of patients.The combination of colonoscopy and immune fecal occult blood detection has garnered significant attention as a novel method for CRC screening.Colonoscopy and fecal occult blood tests,when combined,can improve screening accuracy and early detection rates,thereby facilitating early intervention and treatment.However,certain risks and costs accompany it,making the establishment of a risk classification model crucial for accurate classification and management of screened subjects.AIM To evaluate the feasibility and effectiveness of colonoscopy,immune fecal occult blood test(FIT),and risk-graded screening strategies in CRC screening.METHODS Based on the randomized controlled trial of CRC screening in the population conducted by our hospital May 2020 to May 2023,participants who met the requirements were randomly assigned to a colonoscopy group,an FIT group,or a graded screening group at a ratio of 1:2:2(after risk assessment,the high-risk group received colonoscopy,the low-risk group received an FIT test,and the FITpositive group received colonoscopy).The three groups received CRC screening with different protocols,among which the colonoscopy group only received baseline screening,and the FIT group and the graded screening group received annual follow-up screening based on baseline screening.The primary outcome was the detection rate of advanced tumors,including CRC and advanced adenoma.The population participation rate,advanced tumor detection rate,and colonoscopy load of the three screening programs were compared.RESULTS A total of 19373 subjects who met the inclusion and exclusion criteria were enrolled,including 8082 males(41.7%)and 11291 females(58.3%).The mean age was 60.05±6.5 years.Among them,3883 patients were enrolled in the colonoscopy group,7793 in the FIT group,and 7697 in the graded screening group.Two rounds of follow-up screening were completed in the FIT group and the graded screening group.The graded screening group(89.2%)and the colonoscopy group(42.3%)had the lowest overall screening participation rates,while the FIT group had the highest(99.3%).The results of the intentional analysis showed that the detection rate of advanced tumors in the colonoscopy group was greater than that of the FIT group[2.76%vs 2.17%,odds ratio(OR)=1.30,95%confidence interval(CI):1.01-1.65,P=0.037].There was no significant difference in the detection rate of advanced tumors between the colonoscopy group and the graded screening group(2.76%vs 2.35%,OR=1.9,95%CI:0.93-1.51,P=0.156),as well as between the graded screening group and the FIT group(2.35%vs 2.17%,OR=1.09%,95%CI:0.88-1.34,P=0.440).The number of colonoscopy examinations required for each patient with advanced tumors was used as an index to evaluate the colonoscopy load during population screening.The graded screening group had the highest colonoscopy load(15.4 times),followed by the colonoscopy group(10.2 times),and the FIT group had the lowest(7.8 times).CONCLUSION A hierarchical screening strategy based on CRC risk assessment is feasible for screening for CRC in the population.It can be used as an effective supplement to traditional colonoscopy and FIT screening programs.

Evaluating the Efficacy of Fecal Occult Blood Test and Tumor Marker Combined Screening for Colorectal Cancer

Objective:To analyze the screening effectiveness of combining the fecal occult blood test with tumor marker detection for colorectal cancer.Methods:A total of thirty patients with colorectal cancer and thirty patients with benign colon hyperplasia who received treatment from January 2020 to January 2023 were selected.These patients were assigned to the observation group and the control group,respectively.All patients in both groups underwent both fecal occult blood tests and tumor marker detection.The levels of tumor markers between the two groups were compared,the tumor marker levels in different stages were assessed within the observation group,and the positive detection rates for single detection and combined detection were compared.Results:The levels of various tumor markers in the observation group were significantly higher than those in the control group(P<0.05).Furthermore,as the Duke stage increased within the observation group,the levels of various tumor markers also increased(P<0.05).The positive detection rate of the combined test was notably higher than that of single detection(P<0.05).Conclusion:Combining the fecal occult blood test with tumor marker detection in colorectal cancer screening can significantly improve the overall detection rate.

EVALUATION OF REVERSE PASSIVE HEMAGGLUTINATION （RPHA） FECAL OCCULT BLOOD TEST IN SCREENING OF COLORECTAL NEOPLASIA

A high risk population consisting of 3034 people with history of rectal polyps or ulcers were screened for colorectal neoplasia with Reverse Passive Hemagglutination Fecal Occult Blood Test (RPHA FOB) and 60 cm fiberoptic colonoscopy. Among 2553 subjects (84.1%)who completed both tests, 11 cases of colorectal malignancies and 465 cases of polyps were detected.Using colonoscopic finding and histopathological examination as the 'gold standard' of diagnosis, results showed that FOB positivity of polyps was related to their size, macroscopic appearance and surface features but no correlation between bleeding of polyps and their location, numbers, pathological types were found. In this study the sensitivity of RPHA in screening of colorectal malignancy was 63.6% (7/11), while that for polyps was only 21.1% (98/465) . For screening of colorectal neoplasia (cancer+polyps) the overall sensitivity and specificity of RPHA FOB were 22.1% and 82.4%, the positive and negative predictive values were 22.3% and 82.2% respectively. Amoug 465 polyps there were 195 adenomas, further analysis showed that villous and tubulovillous adenomas had higher intestinal bleeding rate (FOB positive)than tubular type (45.5%,30.0% and 17.8% respectively, X2=5.8, p=0.05). The results indicate that although the sensitivity of RPHA FOB in screening for colorectal polyps was generally low, but about 40% (8/21) of villous and tubulovillous adenoma which present higher tendency of malignant transformation can be detected by RPHA FOB as a screening Procedure. So the authors suggest that screening of colorectal neoplasia be not only a procedure of secondary prevention but also a measure of primary prevention for colorectal cancer.Accepted March 22, 1994

Colorectal cancer screening: Comparison of transferrin and immuno fecal occult blood test

AIM: To evaluate the sensitivity and specificity of transfesrrin dipstick test (Tf) in colorectal cancer (CRC) screening and precancerous lesions screening. METHODS: Eight hundreds and sixty-one individuals at high-risk for CRC were recruited. Six hundreds and eleven subsequently received the three fecal occult blood tests and colonoscopy with biopsy performed as needed. Fecal samples were obtained on the day before colonoscopy. Tf, immuno fecal occult blood test (IFOBT) and guaiac fecal occult blood test (g-FOBT) were performed simultaneously on the same stool. To minimize false-negative cases, all subjects with negative samples were asked to provide an additional stool specimen for a second test even a third test. If the results were all negative after testing three repeated samples, the subject was considered a true negative. The performance characteristics of Tf for detecting CRC and precancerous lesions were examined and compared to those of IFOBT and the combination of Tf, IFOBT and g-FOBT. RESULTS: A total of six hundreds and eleven subjects met the study criteria including 25 with CRC and 60 with precancerous lesions. Sensitivity for detecting CRC was 92% for Tf and 96% for IFOBT, specificities of Tf and IFOBT were both 72.0% (95% CI: 68.2%-75.5%; χ2 = 0.4, P > 0.05); positive likelihood ratios of those were 3.3 (95% CI: 2.8-3.9) and 3.4 (95% CI: 2.9-4.0), respectively. In precancerous lesions, sensitivities for Tf and IFOBT were 50% and 58%, respectively (χ 2 = 0.8, P > 0.05); specificities of Tf and IFOBT were 71.5% (95% CI: 67.6%-75.1%) and 72.2% (95% CI: 68.4%-75.8%); positive likelihood ratios of those were 1.8 (95% CI: 1.3-2.3) and 2.1 (95% CI: 1.6-2.7), respectively; compared to IFOBT, g-FOBT+ Tf+ IFOBT had a significantly higher positive rate for precancerous lesions (83% vs 58%, respectively; χ 2 = 9.1, P < 0.05). In patients with CRC and precancerous lesions, the sensitivities of Tf and IFOBT were 62% and 69% (χ 2 = 0.9, P > 0.05); specificities of those were 74.5% (95% CI: 70.6%-78.1%) and 75.5% (95% CI: 71.6%-79.0%); positive likelihood ratios of those were 2.5 (95% CI: 2.0-3.1) and 2.8 (95% CI: 2.3-3.5). Compared to IF-OBT alone, combining g-FOBT, IFOBT and Tf led to significantly increased sensitivity for detecting CRC and cancerous lesions (69% vs 88%, respectively; χ 2 = 9.0, P < 0.05). CONCLUSION: Tf dipstick test might be used as an ad- ditional tool for CRC and precancerous lesions screening in a high-risk cohort.

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.

Early diagnostic strategies for colorectal cancer

At present,cancer is still an important factor threatening human health.Colorectal cancer(CRC)is one of the top three most common cancers worldwide and one of the deadliest malignancies in humans.The latest data showed that CRC incidence and mortality rank third and second,respectively,among global malignancies.Early and accurate diagnosis is crucial to reduce the morbidity,mortality and improve survival of patients with CRC,but the current early diagnostic methods have limitations.The effectiveness and compliance of diagnostic methods have a certain impact on whether people choose screening.In this editorial,we explore strategies for the early diagnosis of CRC,including stool-based,blood-based,direct visualization,and imaging examinations.

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.

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.

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.

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).

Current and future molecular diagnostics in colorectal cancer and colorectal adenoma

Colorectal cancer(CRC)is one of the most prevalent cancers in developed countries.On the other hand,CRC is also one of the most curable cancers if it is detected in early stages through regular colonoscopy or sigmoidoscopy.Since CRC develops slowly from precancerous lesions,early detection can reduce both the incidence and mortality of the disease.Fecal occult blood test is a widely used non-invasive screening tool for CRC.Although fecal occult blood test is simple and cost-effective in screening CRC,there is room for improvement in terms of the accuracy of the test.Genetic dysregulations have been found to play an important role in CRC development.With better understanding of the molecular basis of CRC,there is a growing expectation on the development of diagnostic tests based on more sensitive and specific molecular markers and those tests may provide a breakthrough to the limitations of current screening tests for CRC.In this review,the molecular basis of CRC development,the characteristics and applications of different non-invasive molecular biomarkers,as well as the technologies available for the detection were discussed.This review intended to provide a summary on the current and future molecular diagnostics in CRC and its pre-malignant state,colorectal adenoma.

Optimal Noninvasive Colon Cancer Screening Modality in Patients Not Receiving Colonoscopy

Colon cancer is the third most common among cancer deaths in the US for both men and women. The incidence of colonoscopy has been soaring in younger patients, which led to changes in recent United States Preventive Services Task Force (USPSTF) guidelines to reduce the age for screening from 50 years to 45 years. Demand for colonoscopy services is surging due to increased incidences of colorectal cancer (CRC) in the both aging and younger population. Increased referrals have led to an insufficient workforce in hospitals and long waiting lists. Further, results from colonoscopy reveal a low percentage of CRC or another severe bowel disease (SBD). Therefore, colon cancer screening is a growing concern, particularly in patients who otherwise have a very long-life expectancy, and who are most likely to benefit from screening. Another reason to boost CRC screening is to minimize the load on hospitals by reducing the patients that undergo colonoscopy unnecessarily because only a low percentage of CRC occurrence is observed in individuals undergoing colonoscopy. In recent years, there are a variety of screening options available for CRC. Noninvasive alternatives include fecal immunochemical test (FIT), multitarget stool DNA testing (MT-sDNA, available under the brand name Cologuard), computed tomography (CT) colonography (previously called virtual colonoscopy), guaiac-based fecal occult blood testing (gFOBT), and capsule colonoscopy (CC). These tests have varied the degree of evidence supporting their use. This study focuses on the most recent survey and efficacy of noninvasive methods to prevent and detect colorectal cancer (CRC).