<h4>Importance</h4>Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.<h4>Objective</h4>To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.<h4>Data sources</h4>MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.<h4>Study selection</h4>English-language studies conducted in asymptomatic populations at general risk of CRC.<h4>Data extraction and synthesis</h4>Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.<h4>Main outcomes and measures</h4>Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.<h4>Results</h4>The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.<h4>Conclusions and relevance</h4>There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

A recent randomized trial has suggested persisting protection from colorectal cancer (CRC) incidence and mortality of a single flexible sigmoidoscopy for up to 17 years and possibly beyond. We performed a simulation study to explore the time course and magnitude of protection provided by screening colonoscopy against CRC death over 25 years. Using data from the German national screening colonoscopy registry, a multistate Markov model was set up based on the adenoma–carcinoma pathway to estimate cumulative CRC mortality when different proportions of the population have a single screening colonoscopy at age 55, or two screening colonoscopies at ages 55 and 65. Cumulative CRC mortality continuously increased with age and reached 2.6 and 1.7% at age 80 in the absence of screening for men and women, respectively. A single colonoscopy at age 55, even with limited uptake, would lead to much lower cumulative mortality (0.7% for men and 0.5% for women at age 80 under 100% uptake). Relative mortality reduction continued to increase over more than 10 years and reached the maximum around 12–13 years after screening. Absolute risk reduction steadily increased throughout follow‐up and more than half of the total risk reduction would occur between 15–25 years. A repeat colonoscopy 10 years later further enhanced the effects and cumulative mortality remained at 0.1–0.2% under 100% uptake. Even a single (once‐only) screening colonoscopy has the potential to prevent most of CRC mortalities. Protective effects are expected to be long‐lasting and to become fully manifest after more than two decades from screening.

Objectives We conducted a comprehensive analysis to compare colonoscopy and sigmoidoscopy with standard care or fecal immunochemistry regarding colorectal cancer incidence and mortality risk. Methods Until August 2023, literature from PubMed, Embase, Web of Science, and Cochrane was systematically reviewed. We examined the impact of colonoscopy or sigmoidoscopy versus standard care on colorectal cancer outcomes, including incidence, cancer-specific mortality, and overall mortality. Results Among 4,265 screened articles, data from seven randomized controlled trials (involving 663,319 participants) were analyzed. The intervention group (colonoscopy or sigmoidoscopy) consisted of 258,938 participants, while the control group received standard care or fecal immunochemical testing, totaling 404,381 participants, with both groups having average colorectal cancer risk, without confounders. Pooled analyses indicated a 20% reduction in colorectal cancer incidence (RR: 0.80, 95% CI: 0.77-0.83) and a 26% decrease in colorectal cancer mortality (RR: 0.74, 95% CI: 0.69-0.80) in the intervention group compared to standard care. All-cause mortality remained unchanged (RR: 1.03, 95% CI: 0.99-1.07). Subgroup analysis favored sigmoidoscopy in reducing colorectal cancer morbidity and mortality. Conclusion This meta-analysis of randomized controlled trials underscores the effectiveness of colonoscopy and, notably, sigmoidoscopy in reducing colorectal cancer incidence and mortality among average-risk populations. In comparison to fecal immunochemical testing, both colonoscopy and sigmoidoscopy did not significantly impact colorectal cancer incidence and mortality in this population. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023460007.

The incidence of colorectal cancer (CRC) has declined over time, though it remains a significant cause of morbidity and mortality in the U.S. It has the third highest incidence in incidence among all cancers and is the second leading cause of cancer death in both men and women. Screening reduces the incidence and mortality from CRC. There are several modalities for CRC screening, but the most common ones are a choice between a non-invasive stool-based test, such as fecal immunochemical testing (FIT) or an invasive endoscopic modality, such as colonoscopy. In the U.S. colonoscopy is the predominant CRC screening modality, with observational studies reporting large reductions in CRC incidence and mortality. Recently, a large randomized controlled trial (RCT) on effectiveness of colonoscopy reported smaller than expected reduction in CRC incidence and no reduction in CRC mortality with colonoscopy screening. Explanations of the lower than expected benefit include low uptake of colonoscopy, short follow-up for mortality endpoints and quality indicators (QIs) for some of the endoscopists participating in the screening colonoscopies. The findings of the study need to be taken in context with other literature on effectiveness of colonoscopy, with the overall message of reassuring patients of the benefits of screening, and colonoscopy. Here, we discuss the latest evidence on colonoscopy screening and it in the context of other screening modalities and the landscape.

Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related death worldwide. Early detection can reduce CRC mortality by more than 90%. Circulating small extracellular vesicles (sEVs) are emerging as promising biomarkers for CRC, but their role in detecting precancerous lesions remains unclear. Herein, parallel proteomic and phosphoproteomic analyses of plasma-derived sEVs were performed in healthy subjects with negative colonoscopy, patients with high-risk adenoma (HRA) and patients with CRC. A total of 139 phosphorylation sites on 52 proteins were identified, among which 16 phosphorylation sites on 12 sEV proteins showed significant changes (≥ 2-fold) with 90% confidence in site localization. Web-based validation demonstrated that the phosphorylation level of sEV-derived filamin-A at serine 1459 (pFLNA^Ser1459) correlated with the Clinical Proteomic Tumor Analysis Consortium colon cancer dataset. Immunoblot analysis confirmed that sEV-derived pFLNA^Ser1459 was significantly reduced in CRC patients compared with healthy subjects, whereas the highest levels were observed in HRA patients. Notably, sEV-derived pFLNA^Ser1459, alone or in combination with FLNA, CD9, and TSG101, showed superior diagnostic performance in distinguishing HRA patients from CRC patients and healthy subjects. These findings suggest that plasma sEV-derived pFLNA^Ser1459 is a promising biomarker for colorectal neoplasm detection.

BACKGROUND: Colonoscopy with a possible polypectomy is an efficient and preferred screening method to reduce the incidence of colorectal cancer (CRC). However, critics argue that, to date, a reduction of incidence and mortality from CRC has not been demonstrated in a population-based setting. OBJECTIVE: To compare the incidence of and mortality from CRC among individuals screened by colonoscopy and non-screened individuals. DESIGN: A closed cohort study. SETTING: Population-based setting in a precisely defined area with a low level of population migration. PATIENTS: This study involved 1912 screened and 20,774 control participants. INTERVENTION: CRC cases in this closed cohort study were prospectively collected during the screening period of 1 year and the follow-up period of 6 years. MAIN OUTCOME MEASUREMENTS: Follow-up data were corrected for negligible migration balance in the area. Tumor characteristics and risk or protective factors, age and sex, participation in general health screening examinations, history of CRC in a first-degree relative, smoking status, body mass index, frequency of sports activity, eating habits, and patients' professions were recorded. RESULTS: Overall cancer incidence was significantly lower in the screened group compared with the non-screened group (adjusted odds ratio [OR] 0.31; 95% confidence interval [CI], 0.16-0.59; P < .001). Colon cancer-associated mortality also was clearly lower (adjusted OR 0.12; 95% CI, 0.01-0.93; P = .04). Risk facto

Colorectal cancer (CRC) is the third most common cause of cancer death worldwide and a major health problem. In this review, the different approaches for CRC screening will be outlined with emphasis on evidence-based medicine. Evidence from randomized trials on the effectiveness of CRC screening is summarized. Several screening tools for CRC are available. They can be categorized according to their mode of action: early detection tools such as the faecal occult blood test (FOBT) and cancer prevention tools such as flexible sigmoidoscopy and colonoscopy. Meta-analyses of randomized trials show that FOBT screening reduces CRC mortality by 16% (risk ratio 0.84; 95% confidence interval (CI) 0.78-0.9) compared with 30% (risk ratio 0.7; 95% CI 0.6-0.81) for flexible sigmoidoscopy screening. FOBT screening is cheap and noninvasive, but results in large numbers of false-positive tests and needs to be repeated frequently. Flexible sigmoidoscopy is more invasive, but is effective for once-only screening. Although colonoscopy screening is used in some countries, no randomized trials have been conducted to estimate its benefit, and therefore, it should not be recommended at the present time. Faecal occult blood test and flexible sigmoidoscopy are the two CRC screening tools that can be recommended as they have been proven to reduce CRC mortality. Colonoscopy has the potential to be superior to FOBT and flexible sigmoidoscopy, but needs to be evaluated in randomized trials before any reco

<h4>Background</h4>Colonoscopy is a widely used screening method for colorectal cancer, playing a crucial role in early detection and prevention by allowing visualization and removal of precancerous lesions. It also helps diagnose and manage neoplastic lesions and inflammatory bowel disease by providing direct visualization of the intestinal mucosa. However, traditional air or carbon dioxide (CO2) insufflation may limit complete visualization of the colon. Alternatively, water infusion causes local distension without elongating the colon (unlike air insufflation), while warm water reduces spasms, decreasing insertion time and patient discomfort.<h4>Objective</h4>This systematic review and meta-analysis aimed to compare water infusion versus air/CO2 insufflation in terms of technical efficacy, evaluate the effect of water immersion on procedural difficulty, and determine the accuracy of water immersion colonoscopy in detecting colon adenomas.<h4>Methods</h4>We searched MEDLINE, EMBASE, and Cochrane CENTRAL databases for randomized controlled trials published from inception to January 2023. Outcomes included adenoma detection rate, success rate of cecal intubation, cecal intubation time, total procedure time (from insertion to withdrawal), need for abdominal compression, and on-demand sedation rate. Thirty randomized controlled trials were included.<h4>Results</h4>adenoma detection rate, success rate of cecal intubation, cecal intubation time, and total procedure time showed no significant difference between the two methods (P>0.05). However, water infusion significantly reduced the proportion of participants requiring on-demand sedation (risk ratio 0.61, 95%CI 0.48-0.77, P=0.02) and abdominal compression (risk ratio 0.65, 95%CI 0.51-0.83, P<0.01).<h4>Conclusion</h4>Colonoscopy with water infusion helps the colonoscope reach the cecum more easily, decreasing the need for on-demand sedation and abdominal compression.

Adenoma Detection Rate With Position Change at Colonoscopy The hypothesis to be tested is that position changes during the withdrawal phase of colonoscopy leads to a higher adenoma (polyp) detection rate because of better distension of the colon. Since adenomas are precancerous lesions the enhanced adenoma detection will increase the success of colorectal cancer screening programmes. This study will provide evidence for the value of position changes and encourage endoscopist to adopt position change as a routine in their practice. May 2007: protocol amendment to include additional prospective analysis using High Definition TV (HDTV). Colorectal cancer is the second commonest cause of cancer death. In a majority of cases it is preceded by a precancerous lesion called an adenoma (commonly known as polyp). Detection and removal of adenomas at colonoscopy has been shown to reduce mortality from colorectal cancer. The success of the impending colorectal cancer screening programme to reduce cancer mortality in an average-risk population depends on optimal adenoma detection at colonoscopy. The detection of adenomas has been shown to vary between different endoscopist.

Surveillance colonoscopy plays an important role in the management of asymptomatic patients known to carry and suspected of carrying hereditary nonpolyposis colorectal cancer gene mutations. Although the shortest interval between surveillance examinations may seem to offer the most benefit to patients, excessive use of this procedure may have unwanted consequences. This study was designed to evaluate the evidence and make recommendations regarding the optimal frequency of surveillance colonoscopy and the age at which to initiate surveillance based on the best available evidence.MEDLINE was searched for all articles assessing surveillance colonoscopy from 1966 to 2004 by using the MESH terms "hereditary nonpolyposis colorectal cancer" and "screening." The evidence was systematically reviewed and a critical appraisal of the evidence was performed.There are no randomized, controlled, clinical trials examining the frequency of surveillance colonoscopy in hereditary nonpolyposis colorectal cancer. Three cohort studies were identified for review. There is one cohort study of good quality that provides evidence that surveillance colonoscopy every three years in patients with hereditary nonpolyposis colorectal cancer reduces the risk of developing colorectal cancer and the risk of death. The two remaining cohort studies provide poor evidence on which to make a recommendation.The best available evidence supports surveillance with complete colonoscopy to the cecum every three years in

Colonoscopy-based screening provides protection against colorectal cancer (CRC), but the optimal starting age and time intervals of screening colonoscopies are unknown. We aimed to determine an optimal screening schedule for the US population and its dependencies on the objective of screening (life years gained or incidence, mortality, or cost reduction) and the setting in which screening is performed. We used our established open-source microsimulation model CMOST to calculate optimized colonoscopy schedules with one, two, three or four screening colonoscopies between 20 and 90 years of age.

Koloskopi är en undersökning av tjocktarmen som förväntas öka i antal eftersom studiervisar att screening minskar dödligheten i kolorektalcancer. Patienten kan i vissa falluppleva undersökningen som smärtsam och obehaglig. Sjuksköterskan har enbetydelsefull roll i omvårdnaden. Syftet med studien var att belysa faktorer sompåverkar upplevelsen av smärta och obehag vid en koloskopiundersökning utansedering. Metoden var en litteraturstudie baserad på 19 vetenskapliga artiklar som harkvalitetsbedömts enligt protokoll. Vid analysen skapades tre övergripande kategorier.Fysiska faktorer som påverkar