Colonoscopy and Colorectal Cancer Mortality in the Veterans Affairs Health Care System: A Case-Control Study

Screening for Colorectal Cancer

Colorectal cancer remains the third leading cause of cancer death in the United States. Colorectal cancer screening allows for prevention and early detection of precancerous and cancerous lesions, and screening has been shown to be effective in preventing colorectal cancer deaths. Screening recommendations vary by patient risk profile. A variety of screening modalities exist.

Colorectal cancer screening: A review of current knowledge and progress in research

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide, being the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths globally. Despite the progress in screening, early diagnosis, and treatment, approximately 20%-25% of CRC patients still present with metastatic disease at the time of their initial diagnosis. Furthermore, the burden of disease is still expected to increase, especially in individuals younger than 50 years old, among whom early-onset CRC incidence has been increasing. Screening and early detection are pivotal to improve CRC-related outcomes. It is well established that CRC screening not only reduces incidence, but also decreases deaths from CRC. Diverse screening strategies have proven effective in decreasing both CRC incidence and mortality, though variations in efficacy have been reported across the literature. However, uncertainties persist regarding the optimal screening method, age intervals and periodicity. Moreover, adherence to CRC screening remains globally low. In recent years, emerging technologies, notably artificial intelligence, and non-invasive biomarkers, have been developed to overcome these barriers. However, controversy exists over the actual impact of some of the new discoveries on CRC-related outcomes and how to effectively integrate them into daily practice. In this review, we aim to cover the current evidence surrounding CRC screening. We will further critically assess novel approaches under investigation, in an effort to differentiate promising innovations from mere novelties.

Contributions of early detection and cancer prevention to colorectal cancer mortality reduction by screening colonoscopy: a validated modeling study

BACKGROUND AND AIMS

Screening colonoscopy, recommended every 10 years, reduces mortality from colorectal cancer (CRC) by early detection of prevalent but undiagnosed CRC, as well as by removal of precursor lesions. The aim of this study was to assess the relative contribution of both components to total CRC mortality reduction over time.

METHODS

Using a validated multistate Markov model, we simulated hypothetical cohorts of 100,000 individuals aged 55 to 64 years with and without screening at baseline. Main outcomes included proportions of prevented CRC deaths arising from (asymptomatic) CRC already present at baseline and from newly developed CRC during 15 years of follow-up, and mortality rate ratios of screened versus nonscreened groups over time.

RESULTS

Early detection of prevalent cases accounted for 52%, 30%, and 18% of deaths prevented by screening colonoscopy within 5, 10, and 15 years, respectively. Relative reduction of mortality was estimated to be much larger for mortality from incident cancers than for mortality from cancers that were already present and detected early at screening endoscopy and for total CRC mortality (ie, 88% versus 67% and 79%, respectively, within 10 years from screening).

CONCLUSIONS

Reduction of CRC mortality mainly arises from early detection of prevalent cancers during the early years after screening colonoscopy, but prevention of incident cases accounts for the majority of prevented deaths in the longer run. Prevention of incident cases leads to sustained strong reduction of CRC mortality, possibly warranting an extension of screening intervals.

Effectiveness of Colonoscopy Screening vs Sigmoidoscopy Screening in Colorectal Cancer

Importance

Randomized clinical screening trials have shown that sigmoidoscopy screening reduces colorectal cancer (CRC) incidence and mortality. Colonoscopy has largely replaced sigmoidoscopy for CRC screening, but long-term results from randomized trials on colonoscopy screening are still lacking.

Objective

To estimate the additional screening benefit of colonoscopy compared with sigmoidoscopy.

Design, Setting, and Participants

This comparative effectiveness simulation study pooled data on 358 204 men and women randomly assigned to sigmoidoscopy screening or usual care in 4 randomized sigmoidoscopy screening trials conducted in Norway, Italy, the US, and UK with inclusion periods in the years 1993 to 2001. The primary analysis of the study was conducted from January 19 to December 30, 2021.

Intervention

Invitation to endoscopic screening.

Main Outcomes and Measures

Primary outcomes were CRC incidence and mortality. Using pooled 15-year follow-up data, colonoscopy screening effectiveness was estimated assuming that the efficacy of colonoscopy in the proximal colon was similar to that observed in the distal colon in the sigmoidoscopy screening trials. The simulation model was validated using data from Norwegian participants in a colonoscopy screening trial.

Results

This analysis included 358 204 individuals (181 971 women [51%]) aged 55 to 64 years at inclusion with a median follow-up time ranging from 15 to 17 years. Compared with usual care, colonoscopy prevented an estimated 50 (95% CI, 42-58) CRC cases per 100 000 person-years, corresponding to 30% incidence reduction (rate ratio, 0.70 [95% CI, 0.66-0.75]), and prevented an estimated 15 (95% CI, 11-19) CRC deaths per 100 000 person-years, corresponding to 32% mortality reduction (rate ratio, 0.68 [95% CI, 0.61-0.76]). The additional benefit of colonoscopy screening compared with sigmoidoscopy was 12 (95% CI, 10-14) fewer CRC cases and 4 (95% CI, 3-5) fewer CRC deaths per 100 000 person-years, corresponding to percentage point reductions of 6.9 (95% CI, 6.0-7.9) for CRC incidence and 7.6 (95% CI, 5.7-9.6) for CRC mortality. The number needed to switch from sigmoidoscopy to colonoscopy screening was 560 (95% CI, 486-661) to prevent 1 CRC case and 1611 (95% CI, 1275-2188) to prevent 1 CRC death.

Conclusions and Relevance

The findings of this comparative effectiveness study assessing long-term follow-up after CRC screening suggest that there was an additional preventive effect on CRC incidence and mortality associated with colonoscopy screening compared with sigmoidoscopy screening, but the additional preventive effect was less than what was achieved by introducing sigmoidoscopy screening where no screening existed. The results probably represent the upper limit of what may be achieved with colonoscopy screening compared with sigmoidoscopy screening.

Why is early detection of colon cancer still not possible in 2023?

Colorectal cancer (CRC) screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers. Over the years, screening, particularly in those settings where it is well organized, has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them. Despite considerable advancements in screening technologies and strategies, the effectiveness of CRC screening programs remains less than optimal. This paper examined the multifaceted reasons behind the persistent lack of effectiveness in CRC screening initiatives. Through a critical analysis of current methodologies, technological limitations, patient-related factors, and systemic challenges, we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates. While acknowledging the advancements that have improved aspects of screening, we emphasized the necessity of addressing the identified barriers comprehensively. This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease. Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage. Spending more sooner can mean saving money later.

The effect of nurse assisted colonoscopy on adenoma detection rates: A meta-analysis of randomized controlled trials

BACKGROUND

Adenoma's detection rates have been reported to vary with the participation status of endoscopic nurses during colonoscopy. This meta-analysis was conducted to determine whether the participation of endoscopy nurses during colonoscopy contributed to the improved detection rate of polyps and adenomas.

METHODS

We retrieved English original research from PubMed, Embase, Web of Science, and Cochrane library databases and Chinese original research from the CNKI Data database. We searched for randomized controlled trials (RCTs) comparing the effect of participation of endoscopy nurses during colonoscopy of colorectal polyps and adenomas on polyp detection rates to that of nonparticipation. RevMan5.4 software was used to perform the meta-analysis.

RESULTS

This meta-analysis included 11 randomized controlled trials involving 8278 patients. The results showed no significant difference between colonoscopies performed by nurses and endoscopists, but colonoscopies performed by two nurses significantly improved the detection rate of polyps and adenomas. In the random effects model, there was a significant difference in PDR between the single-observation and dual-observation groups (RR, 1.27; 95%CI, 1.05, 1.54; Z = 2.51; P = 0.01). The ADR difference between the single observation group and the double observation group was statistically significant (RR, 1.15; 95%CI, 1.05, 1.26; Z = 2.91; P = 0.004).

CONCLUSION

Endoscopy nurses' participation in colonoscopy can improve the detection rate of polyps and adenomas, However, more research is needed to confirm the results.

Colonoscopy compliance and diagnostic yield in a large population-based colorectal cancer screening programme

OBJECTIVES

With the intention of providing a reference for secondary prevention, our study provides some insight on diagnostic yield of factors influencing compliance with colonoscopy and the presence of advanced adenomas (AA).

METHODS

We conducted large-scale CRC screening among local Tianjin residents aged 40-75 years between 2012 and 2019. A high-risk factor questionnaire (HRFQ) was distributed to each participant, followed by the performance of a fecal immunochemical test (FIT). Participants who tested positively for any of these items were advised to undergo a colonoscopy. Relevant basic information was collected from participants during CRC screening, and the screening data were sorted and analysed.

RESULTS

A total of 5,670,924 people participated in CRC screening by the end of 2019, including 275,708 people in the high-risk group, and 74,685 (27.1%) people who underwent colonoscopy. The results of the logistic regression model demonstrated that participants with a history of mucous bloody stool (OR = 8.20, 95% CI: 7.92, 8.50, p < 0.001), chronic diarrhea (OR = 5.73, 95% CI: 5.57, 5.89, p < 0.001), and higher level of education (OR = 1.87, 95% CI: 1.80, 1.93, p < 0.001) were more likely to comply with a colonoscopy. Several factors including age (70-75 years old:OR = 3.72, 95% CI: 2.71, 5.10, p < 0.001), and FIT( +) (OR = 1.65, 95% CI: 1.42,1.90, p < 0.001) were identified to be associated with the presence of AA.

CONCLUSIONS

Increased compliance with colonoscopy is urgently needed. Our findings can inform the design of future effective large-scale population-based CRC screening programmes.

Post-traumatic stress disorder is associated with a higher rate of polypectomy independent of an increased frequency of colonoscopy in Australian veterans: a retrospective review

BACKGROUND

Post-traumatic stress disorder (PTSD) is associated with extensive physical comorbidities, including lower gastrointestinal symptoms. Diagnostic uncertainty and poor therapeutic responses may result in more frequent colonoscopies than clinically necessary. Polypectomy is standard practice when polyps are identified, and if PTSD is a risk factor for polyp formation, one would expect a higher rate of polyp detection and removal in veterans with PTSD than those without PTSD.

AIM

To determine the association between PTSD and the rate of colonoscopy and polypectomy in Australian veterans.

METHODS

Diagnostic and therapeutic colonoscopy rates in Australian male Veterans aged ≥50 years were examined by reviewing case records of veterans who accessed Department of Veterans' Affairs funded health services between 1 January 2013 and 31 December 2018.

RESULTS

A total of 138 471 veterans was included, of whom 28 018 had a diagnosis of PTSD; 56.4% were aged ≥65 years. Twenty-one percent of the entire cohort underwent at least one colonoscopy during the study period. Increased rates of diagnostic colonoscopy and polypectomy were associated with the presence of PTSD across all age brackets. The effect was empirically large as veterans with PTSD experience colonoscopy rates 76-81% greater than those without PTSD. Similarly, veterans with PTSD experienced polypectomy rates 76-81% greater than veterans without PTSD, and this increase persisted when controlling for the increased number of diagnostic colonoscopies they undergo.

CONCLUSION

The presence of PTSD has a marked impact on colonoscopy rates in Australian veterans. The increased polypectomy rate independent of increased colonoscopy rate suggests that PTSD is a risk factor for colonic polyp formation.

A Review of Colonoscopy in Intestinal Diseases

Since the development of the fiberoptic colonoscope in the late 1960s, colonoscopy has been a useful tool to diagnose and treat various intestinal diseases. This article reviews the clinical use of colonoscopy for various intestinal diseases based on present and future perspectives. Intestinal diseases include infectious diseases, inflammatory bowel disease (IBD), neoplasms, functional bowel disorders, and others. In cases of infectious diseases, colonoscopy is helpful in making the differential diagnosis, revealing endoscopic gross findings, and obtaining the specimens for pathology. Additionally, colonoscopy provides clues for distinguishing between infectious disease and IBD, and aids in the post-treatment monitoring of IBD. Colonoscopy is essential for the diagnosis of neoplasms that are diagnosed through only pathological confirmation. At present, malignant tumors are commonly being treated using endoscopy because of the advancement of endoscopic resection procedures. Moreover, the characteristics of tumors can be described in more detail by image-enhanced endoscopy and magnifying endoscopy. Colonoscopy can be helpful for the endoscopic decompression of colonic volvulus in large bowel obstruction, balloon dilatation as a treatment for benign stricture, and colon stenting as a treatment for malignant obstruction. In the diagnosis of functional bowel disorder, colonoscopy is used to investigate other organic causes of the symptom.

Characterizing close-focus lenses for microendoscopy

Microendoscopes are commonly used in small lumens in the body, for which a focus near to the distal tip and ability to operate in an aqueous environment are paramount for navigation and disease detection. Commercially available distal optic systems below 1mm in diameter are severely limited, and custom micro lenses are generally very expensive. Gradient index of refraction (GRIN) singlets are available in small diameters but have limited optical performance adjustability. Three-dimensional (3D) printed monolithic optical systems are an emerging option that may be suitable for enabling high performance, close-focus imaging. In this manuscript, we compared the optical performance of three custom distal optic systems; a custom-pitch GRIN singlet, 3D-printed monolithic doublet, and 3D-printed monolithic triplet, with a nominal working distance (WD) of 1.5mm, 0.5mm and 0.4mm in 0.9% saline. These short WDs are ideal for microendoscopy in collapsed or flushed lumens such as pancreatic duct or fallopian tube. The GRIN singlet had performance limited only by the fiber bundle relay over 0.9mm to 1.6 mm depth of field (DOF). The 3D printed doublet was able to achieve a comparable DOF of 0.71mm, while the 3D printed triplet suffered the most limited DOF of 0.55mm. 3D printing enables flexible design of monolithic multi-element systems with aspheric surfaces of very short WDs and relative ease of integration.

Colonoscopy decreases mortality in colorectal cancer patients compared with fecal immunochemical test

BACKGROUND AND AIM

Colonoscopy and fecal immunochemical test (FIT) are commonly used screening methods for the detection of colorectal cancer (CRC), but their effects on survival have not been compared. We compared survival outcomes in patients with CRC according to the exposure history to colonoscopy or FIT before diagnosis of CRC.

METHODS

We performed a nationwide population-based retrospective cohort study using Korean national-insurance claims data. In total, 24 875 patients with CRC diagnosed in 2012 were included. The patients were divided into three groups in terms of examinations performed during the 10 years prior to CRC diagnosis: the colonoscopy group, the FIT group, and the never-screened group. Survival outcomes were compared among the three groups. The colonoscopy group and FIT group were matched using propensity score-matching method.

RESULTS

The cohort consisted of 9619 patients in the colonoscopy group, 6936 patients in the FIT group, and 8320 patients in the never-screened group. The 5-year overall survival rates were 74.1% in the colonoscopy group, 65.9% in the FIT group, and 59.6% in the never-screened group (P < 0.001). The adjusted hazard ratios for death were 0.56 (95% confidence interval [CI], 0.53-0.59) in the colonoscopy group and 0.78 (95% CI, 0.74-0.82) in the FIT group compared with the never-screened group. In the matched cohort, the adjusted hazard ratios for death was 0.76 (95% CI, 0.72-0.81) in the colonoscopy group compared with the FIT group.

CONCLUSION

Colonoscopy is a more effective method for reducing mortality in patients with CRC compared with FIT.

Colorectal Cancer Screening With High Risk-Factor Questionnaire and Fecal Immunochemical Tests Among 5, 947, 986 Asymptomatic Population: A Population-Based Study

Background

The recent uptrend in colorectal cancer (CRC) incidence in China is causing an increasingly overwhelming social burden. And its occurrence can be effectively reduced by sensitizing CRC screening for early diagnosis and treatment. However, a large number of people in China do not undergo screening due to multiple factors. To address this issue, since 2012, a CRC screening program has been initiated in Tianjin.

Methods

Residents aged 40-74 years were eligible for CRC screening. The first was to complete the high-risk factor questionnaire (HRFQ) and undergo fecal immunochemical test (FIT). Then those with a positive result in any of the two screening methods were recommended for a free colonoscopy.

Results

The detection rate of intestinal diseases increased with age, had a male predominance, and was higher in residents from central urban areas and those with primary school above education level. The sensitivity of predicting CRC after colonoscopy in the high-risk group was 76.02%; the specificity was 25.33%.A significant decrease in the detection rate of intestinal disease, CRC and advanced adenoma was observed from positive FIT, the high-risk group and positive HRFQ, 47.13%, 44.79%, 42.30%; 3.15%, 2.44%, 1.76%; 7.72%, 6.42%, 5.08%, in that order, while no inter-group difference was found for the detection of polyps. In addition, the different combinations of HRFQ and FIT can enroll more high-risk population than FIT or (and) HRFQ only, and thus detect more intestinal diseases (include CRC/AA/Polyp).

Conclusion

The superimposition of different screening method for HRFQ and FIT is an effective strategy for the detection of CRC, AA, and Polyp, compared to HRFQ or FIT alone. However, further improvements in screening and interventions are needed to promote colonoscopy compliance.

CT imaging findings of complications of optical colonoscopy

Colonoscopy is one of the most commonly performed endoscopic procedures and remains the most commonly used screening modality method for colorectal cancer (CRC) screening in the USA. Although serious complications of fiberoptic colonoscopy are uncommon due to technical advances, due to increasing number of colonoscopy procedures, post-procedural complications are not uncommonly encountered in the routine clinical practice. Also, as some of the post-colonoscopy complications are life threatening, it is important to diagnose them early so that timely treatment measures can be taken to decrease mortality and morbidity. In this review, we present a case-based illustration of the utility of CT to detect complications of colonoscopy including bowel perforation, hemorrhage, splenic injury, and postpolypectomy syndrome.

Effectiveness of a tailored communication intervention on colonoscopy uptake for firstdegree relatives of colorectal cancer patients: A randomised controlled trial

Objective

To evaluate the effect of a WeChat tailored communication intervention on colonoscopy uptake and health beliefs in Chinese first-degree relatives (FDRs) of colorectal cancer patients.

Methods

This study employed a single-blinded randomized controlled trial. A total of 188 eligible FDRs were recruited and randomly assigned to the tailored intervention group or control group. Health beliefs were assessed at 1 (T1) and 3 months (T2) postintervention. The colonoscopy uptake was verified by medical records at T2. Data were analyzed using binary logistic regression and generalized estimating equation models.

Results

Compared with the participants in the control group, those in the intervention group had a significant improvement in terms of colonoscopy uptake (OR = 2.752, 95% CI: 1.428–5.303, P ​< ​0.01), perceived susceptibility (T1: β ​= ​0.298, 95% CI: ​0.052–0.402, P ​< ​0.05; T2: β ​= ​0.251, 95% CI: ​0.078–0.424, P ​< ​0.001) and cues to action (T1: β ​= ​0.0.264, 95% CI: ​0.138–0.389, P ​< ​0.001; T2: β ​= ​0.327, 95% CI: ​0.195–0.459, P ​< ​0.001) and a significant reduction in perceived barriers (T1: β ​= ​−0.237, 95% CI: ​−0.360−0.115, P ​< ​0.01; T2: β ​= ​−0.196, 95% CI: ​−0.331−0.062, P ​< ​0.01).

Conclusions

This study broadens the application of tailored communication using novel channels in the context of screening in the at-risk Chinese population. The results provide insights on how to improve the intervention by modifying its components and communication channels.

Current and future colorectal cancer screening strategies

Despite strong evidence of effectiveness, colorectal cancer (CRC) screening remains underused. Currently, there are several options for CRC screening, each with its own performance characteristics and considerations for practice. This Review aims to cover current CRC screening guidelines and highlight future blood-based and imaging-based options for screening. In current practice, the leading non-invasive option is the faecal immunochemical test (FIT) based on its high specificity, good sensitivity, low cost and ease of use in mailed outreach programmes. There are currently five blood-based CRC screening tests in varying stages of evaluation, including one that is currently sold in the USA as a laboratory-developed test. There are ongoing studies on the diagnostic accuracy and longitudinal performance of blood tests and they have the potential to disrupt the CRC screening landscape. Imaging-based options, including the colon capsule, MR colonography and the CT capsule, are also being tested in active studies. As the world attempts to recover from the COVID-19 pandemic and adapts to the start of CRC screening among people at average risk starting at age 45 years, non-invasive options will become increasingly important.

Detection Accuracy and Latency of Colorectal Lesions with Computer-Aided Detection System Based on Low-Bias Evaluation

We developed a computer-aided detection (CADe) system to detect and localize colorectal lesions by modifying You-Only-Look-Once version 3 (YOLO v3) and evaluated its performance in two different settings. The test dataset was obtained from 20 randomly selected patients who underwent endoscopic resection for 69 colorectal lesions at the Jikei University Hospital between June 2017 and February 2018. First, we evaluated the diagnostic performances using still images randomly and automatically extracted from video recordings of the entire endoscopic procedure at intervals of 5 s, without eliminating poor quality images. Second, the latency of lesion detection by the CADe system from the initial appearance of lesions was investigated by reviewing the videos. A total of 6531 images, including 662 images with a lesion, were studied in the image-based analysis. The AUC, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.983, 94.6%, 95.2%, 68.8%, 99.4%, and 95.1%, respectively. The median time for detecting colorectal lesions measured in the lesion-based analysis was 0.67 s. In conclusion, we proved that the originally developed CADe system based on YOLO v3 could accurately and instantaneously detect colorectal lesions using the test dataset obtained from videos, mitigating operator selection biases.

Decreased colorectal cancer incidence and mortality in a diverse urban population with increased colonoscopy screening

Background

Although colorectal cancer screening has contributed to decreased incidence and mortality, disparities are present by race/ethnicity. The Citywide Colon Cancer Control Coalition (C5) and NYC Department of Health and Mental Hygiene (DOHMH) promoted screening colonoscopy from 2003 on, and hypothesized future reductions in CRC incidence, mortality and racial/ethnic disparities.

Methods

We assessed annual percent change (APC) in NYC CRC incidence, stage and mortality rates through 2016 in a longitudinal cross-sectional study of NY State Cancer Registry, NYC Vital Statistics, and NYC Community Health Survey (CHS) data. Linear regression tested associations between CRC mortality rates and risk factors.

Results

Overall CRC incidence rates from 2000 decreased 2.8% yearly from 54.1 to 37.3/100,000 population in 2016, and mortality rates from 2003 decreased 2.9% yearly from 21.0 to 13.9 in 2016 at similar rates for all racial/ethnic groups. Local stage disease decreased overall with a transient increase from 2002 to 2007. In 2016, CRC incidence was higher among Blacks (42.5 per 100,000) than Whites (38.0), Latinos (31.7) and Asians (30.0). In 2016, Blacks had higher mortality rates (17.9), than Whites (15.2), Latinos (10.4) and Asians (8.8). In 2016, colonoscopy rates among Blacks were 72.2%, Latinos 71.1%, Whites 67.2%, and Asians, 60.9%. CRC mortality rates varied by neighborhood and were independently associated with Black race, CRC risk factors and access to care.

Conclusions

In a diverse urban population, a citywide campaign to increase screening colonoscopy was associated with decreased incidence and mortality among all ethnic/racial groups. Higher CRC burden among the Black population demonstrate more interventions are needed to improve equity.

Colorectal Cancer Incidence After Colonoscopy at Ages 45-49 or 50-54 Years

BACKGROUND & AIMS

Colorectal cancer (CRC) incidence at ages younger than 50 years is increasing, leading to proposals to lower the CRC screening initiation age to 45 years. Data on the effectiveness of CRC screening at ages 45-49 years are lacking.

METHODS

We studied the association between undergoing colonoscopy at ages 45-49 or 50-54 years and CRC incidence in a retrospective population-based cohort study using Florida's linked Healthcare Cost and Utilization Project databases with mandated reporting from 2005 to 2017 and Cox models extended for time-varying exposure.

RESULTS

Among 195,600 persons with and 2.6 million without exposure to colonoscopy at ages 45-49 years, 276 and 4844 developed CRC, resulting in CRC incidence rates of 20.8 (95% CI, 18.5-23.4) and 30.6 (95% CI, 29.8-31.5) per 100,000 person-years, respectively. Among 660,248 persons with and 2.4 million without exposure to colonoscopy at ages 50-54 years, 798 and 6757 developed CRC, resulting in CRC incidence rates of 19.0 (95% CI, 17.7-20.4) and 51.9 (95% CI, 50.7-53.1) per 100,000 person-years, respectively. The adjusted hazard ratios for incident CRC after undergoing compared with not undergoing colonoscopy were 0.50 (95% CI, 0.44-0.56) at ages 45-49 years and 0.32 (95% CI, 0.29-0.34) at ages 50-54 years. The results were similar for women and men (hazard ratio, 0.48; 95% CI, 0.40-0.57 and hazard ratio, 0.52; 95% CI, 0.43-0.62 at ages 45-49 years, and hazard ratio, 0.35; 95% CI, 0.31-0.39 and hazard ratio, 0.29; 95% CI, 0.26-0.32 at ages 50-54 years, respectively).

CONCLUSIONS

Colonoscopy at ages 45-49 or 50-54 years was associated with substantial decreases in subsequent CRC incidence. These findings can inform screening guidelines.

Strong Reduction of Colorectal Cancer Incidence and Mortality After Screening Colonoscopy: Prospective Cohort Study From Germany

INTRODUCTION

A claimed advantage of colonoscopy over sigmoidoscopy in colorectal cancer (CRC) screening is prevention of CRC not only in the distal colon and rectum but also in the proximal colon. We aimed to assess the association of screening colonoscopy use with overall and site-specific CRC incidence and associated mortality.

METHODS

Information on use of screening colonoscopy as well as potential confounding factors was obtained at baseline in 2000-2002, updated at 2-, 5-, 8-, and 17-year follow-up from 9,207 participants aged 50-75 years without history of CRC in a statewide cohort study in Saarland, Germany. Covariate-adjusted associations of screening colonoscopy with CRC incidence and mortality, which were obtained through record linkage with the Saarland Cancer Registry and mortality statistics up to 2018, were assessed by Cox proportional hazards models with time-varying exposure information.

RESULTS

During a median follow-up of 17.2 years, 268 participants were diagnosed with CRC and 98 died from CRC. Screening colonoscopy was associated with strongly reduced CRC incidence (adjusted hazard ratio [aHR] 0.44, 95% confidence interval [CI] 0.33-0.57) and mortality (aHR 0.34, 95% CI 0.21-0.53), with stronger reduction for distal (aHRs 0.36, 95% CI 0.25-0.51, and 0.33, 95% CI 0.19-0.59, respectively) than for proximal cancer (aHRs 0.69, 95% CI 0.42-1.13, and 0.62, 95% CI 0.26-1.45, respectively). Nevertheless, strong reduction of mortality from proximal cancer was also observed within 10 years after screening colonoscopy (aHR 0.31, 95% CI 0.10-0.96).

DISCUSSION

In this large prospective cohort study from Germany, screening colonoscopy was associated with strong reduction in CRC incidence and mortality.

ACG Clinical Guidelines: Colorectal Cancer Screening 2021

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC screening efforts are directed toward removal of adenomas and sessile serrated lesions and detection of early-stage CRC. The purpose of this article is to update the 2009 American College of Gastroenterology CRC screening guidelines. The guideline is framed around several key questions. We conducted a comprehensive literature search to include studies through October 2020. The inclusion criteria were studies of any design with men and women age 40 years and older. Detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC are discussed. We also provide recommendations on the role of aspirin for chemoprevention, quality indicators for colonoscopy, approaches to organized CRC screening and improving adherence to CRC screening. CRC screening must be optimized to allow effective and sustained reduction of CRC incidence and mortality. This can be accomplished by achieving high rates of adherence, quality monitoring and improvement, following evidence-based guidelines, and removing barriers through the spectrum of care from noninvasive screening tests to screening and diagnostic colonoscopy. The development of cost-effective, highly accurate, noninvasive modalities associated with improved overall adherence to the screening process is also a desirable goal.

Effects of screening for colorectal cancer: Development, documentation and validation of a multistate Markov model

Simulation models are a powerful tool to overcome gaps of evidence needed to inform medical decision-making. Here, we present development and application of COSIMO, a Markov-based Colorectal Cancer (CRC) Multi-state Simulation Model to simulate effects of CRC screening, along with a thorough assessment of the model's ability to reproduce real-life outcomes. Firstly, we provide a comprehensive documentation of COSIMO's development, structure and assumptions. Secondly, to assess the model's external validity, we compared model-derived cumulative incidence and prevalences of colorectal neoplasms to (a) results from KolosSal, a study in German screening colonoscopy participants, (b) registry-based estimates of CRC incidence in Germany, and (c) outcome patterns of randomized sigmoidoscopy screening studies. We found that (a) more than 90% of observed prevalences in the KolosSal study were within the 95% confidence intervals of the model-predicted neoplasm prevalences; (b) the 15-year cumulative CRC incidences estimated by simulations for the German population deviated by 0.0% to 0.2% units in men and 0.0% to 0.3% units in women when compared to corresponding registry-derived estimates; and (c) the time course of cumulative CRC incidence and mortality in the modeled intervention group and control group closely resembles the time course reported from sigmoidoscopy screening trials. Overall, COSIMO adequately predicted colorectal neoplasm prevalences and incidences in a German population for up to 25 years, with estimated patterns of the effect of screening colonoscopy resembling those seen in registry data and real-world studies. This suggests that the model may represent a valid tool to assess the comparative effectiveness of CRC screening strategies.

Accuracy of medical billing data against the electronic health record in the measurement of colorectal cancer screening rates

OBJECTIVE

Medical billing data are an attractive source of secondary analysis because of their ease of use and potential to answer population-health questions with statistical power. Although these datasets have known susceptibilities to biases, the degree to which they can distort the assessment of quality measures such as colorectal cancer screening rates are not widely appreciated, nor are their causes and possible solutions.

METHODS

Using a billing code database derived from our institution's electronic health records, we estimated the colorectal cancer screening rate of average-risk patients aged 50-74 years seen in primary care or gastroenterology clinic in 2016-2017. 200 records (150 unscreened, 50 screened) were sampled to quantify the accuracy against manual review.

RESULTS

Out of 4611 patients, an analysis of billing data suggested a 61% screening rate, an estimate that matches the estimate by the Centers for Disease Control. Manual review revealed a positive predictive value of 96% (86%-100%), negative predictive value of 21% (15%-29%) and a corrected screening rate of 85% (81%-90%). Most false negatives occurred due to examinations performed outside the scope of the database-both within and outside of our institution-but 21% of false negatives fell within the database's scope. False positives occurred due to incomplete examinations and inadequate bowel preparation. Reasons for screening failure include ordered but incomplete examinations (48%), lack of or incorrect documentation by primary care (29%) including incorrect screening intervals (13%) and patients declining screening (13%).

CONCLUSIONS

Billing databases are prone to substantial bias that may go undetected even in the presence of confirmatory external estimates. Caution is recommended when performing population-level inference from these data. We propose several solutions to improve the use of these data for the assessment of healthcare quality.

Experience of nurse practitioners performing colonoscopy after endoscopic training in more than 1,000 patients

Background and study aims  The demand for screening colonoscopy has continued to rise over the past two decades. As a result, the current workforce of gastroenterologists is unable to meet the needs for colorectal cancer (CRC) screening. Therefore, solutions are needed to improve this disparity, with non-physician endoscopists being a potential option. However, current literature on the performance of non-physicians in endoscopy is limited. The aim of this study was to assess the quality of colonoscopy performed by three gastrointestinal fellowship-trained nurse practitioners (NPs). Methods  This was a retrospective study performed at a single tertiary academic medical center. Colonoscopies performed by three gastrointestinal-specialized NPs after having completed training of at least 140 supervised colonoscopies were reviewed for analysis. Inclusion criteria were patients undergoing colonoscopy for colorectal cancer screening purposes. Outcomes included colonoscopy quality indicators as defined by the American Society for Gastrointestinal Endoscopy/American College of Gastroenterology Taskforce (ASGE/ACG) Taskforce. Results  The study included 1,012 subjects (mean age 56.2 years, female 51.5 %, African American 73.9 %) who underwent screening colonoscopies by three NPs. Cecal intubation was successful in 997 subjects (98.5 %). Mean adenoma detection rate was 35.6 %. Mean withdrawal time was 18.9 minutes. There were no adverse events including colonic perforations or delayed post-polypectomy bleeding. Conclusions  Three fellowship-trained NPs in colonoscopy in the United States satisfied the quality indicators proposed by the ASGE/ACG Task force, demonstrating that adequately trained NPs can perform colonoscopy safely and effectively. With the demand for colonoscopy exceeding the supply, non-physicians could be part of the solution to meet the demands for CRC screening.

Polyp Detection Rate Correlates Strongly with Adenoma Detection Rate in Trainee Endoscopists

BACKGROUND

The adenoma detection rate (ADR) is a widely accepted quality benchmark for screening colonoscopy but can be burdensome to calculate. Previous studies have shown good correlation between polyp detection rate (PDR) and ADR, but this has not been validated in trainees. Additionally, the correlation between PDR and detection rates for sessile serrated polyps (SSPDR) and advanced neoplasia (ANDR) is not well studied.

AIMS

We investigated the relationship between PDR and ADR, SSPDR, and ANDR in trainees.

METHODS

We examined 1600 outpatient colonoscopies performed by 24 trainees at a VA hospital from 2014 to 2017. Variables collected included patient demographics, year of fellowship, colonoscopy indication, and endoscopic and histologic findings. We calculated the overall ratios of PDR to ADR, SSPDR, and ANDR to assess the correlation between measured and calculated ADR, SSPDR, and ANDR, which is equivalent to the correlation between PDR and measured ADR, SSPDR, and ANDR.

RESULTS

The overall PDR, ADR, SSPDR, and ANDR were 72%, 52%, 2%, and 14%. PDR (48%) was highest in the left colon, while ADR (32%) and ANDR (7%) were highest in the right colon (p < 0.001 for all). The overall ADR/PDR, SSPDR/PDR, and ANDR/PDR ratios were 0.73, 0.03, and 0.20. Correlation between PDR and ADR was highly positive overall (r = 0.87, p < 0.0001) and stronger in the right (r = 0.91) and transverse (r = 0.94) colon than the left colon (r = 0.80). Correlation between PDR and overall SSPDR and ANDR were not statistically significant.

CONCLUSIONS

PDR can serve as a surrogate measure of ADR to monitor colonoscopy quality in gastroenterology fellowship.

Serum piRNA-54265 is a New Biomarker for early detection and clinical surveillance of Human Colorectal Cancer

Background: Our previous study has demonstrated an oncogenic role of PIWI-interacting RNA-54265 (piR-54265) in colorectal cancer (CRC). Here, we investigate whether it can be a blood biomarker for population screening and clinical applications.

Methods: Serum piR-54265 levels were determined by a digital PCR method in 209 cancer-free healthy controls, 725 patients with CRC, 1303 patients with other types of digestive cancer and 192 patients with benign colorectal tumors. A prospective case-control analysis was conducted to assess the predictive value of serum piR-54265 for future CRC diagnosis. Receiver operating characteristic (ROC) curve was constructed to quantify the diagnostic performance of serum piR-54265 levels by assessing its sensitivity, specificity and respective areas under curve (AUC). The odds ratios (ORs) were computed using multivariate logistic regression models.

Results: Serum piR-54265 levels were significantly elevated only in patients with CRC compared with controls and patients with other cancer types. The AUC for recognizing CRC was 0.896 (95% CI, 0.874-0.914), with a sensitivity and specificity being 85.7% and 65.1% at 1500 copies/µL as a cut-off value. The serum piR-54265 levels in patients declined substantially after surgery but increased significantly again when tumor relapses. The prediagnostic serum piR-54265 levels were significantly associated with future CRC diagnosis, with the ORs of 7.23, 2.80, 2.45, and 1.24 for those whose CRC was diagnosed within 1, 2, 3 and >3 years. Serum piR-54265 test is more sensitive than other blood CRC markers.

Conclusion: Serum piR-54265 may serve as a valuable biomarker for CRC screening, early detection and clinical surveillance.

Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance

BACKGROUND & AIMS

Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous histology or high-grade dysplasia, or colorectal cancer [CRC]) and assessed whether baseline colonoscopy findings were associated with long-term outcomes.

METHODS

We collected data from the Department of Veterans Affairs Cooperative Studies Program Study on 3121 asymptomatic veterans (50-75 years old) who underwent a screening colonoscopy from 1994 through 1997 at 13 medical centers and were then followed for 10 years or until death. We included 1915 subjects with at least 1 surveillance colonoscopy and estimated cumulative incidence of advanced neoplasia by Kaplan-Meier curves. We then fit a longitudinal joint model to estimate risk of advanced neoplasia at each subsequent examination after baseline, adjusting for multiple colonoscopies within individuals.

RESULTS

Through 10 years of follow-up, there were 146 individuals among all baseline colonoscopy groups found to have at least 1 incident advanced neoplasia. The cumulative 10-year incidence of advanced neoplasia was highest among those with baseline CRC (43.7%; 95% CI 13.0%-74.4%), followed by those with baseline advanced adenoma (AA) (21.9%; 95% CI 15.7-28.1). The cumulative 10-year incidence of advanced neoplasia was 6.3% (95% CI 4.1%-8.5%) and 4.1% (95% CI 2.7%-5.4%) for baseline 1 to 2 small adenomas (<1cm, and without villous histology or high-grade dysplasia) and no neoplasia, respectively (log-rank P = .10). After adjusting for prior surveillance, the risk of advanced neoplasia at each subsequent examination was not significantly increased in veterans with 1 or 2 small adenomas at baseline (odds ratio 0.96; 95% CI 0.67-1.41) compared with veterans with no baseline neoplasia.

CONCLUSIONS

Baseline screening colonoscopy findings associate with advanced neoplasia within 10 years. Individuals with only 1 or 2 small adenomas at baseline have a low risk of advanced neoplasia over 10 years. Alternative surveillance strategies, could be considered for these individuals.

Strategies for Colorectal Cancer Screening

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

Adverse events associated with colonoscopy; an examination of online concerns

Background

Colonoscopy as a screening and diagnostic tool is generally safe and well-tolerated, and significant complications are rare. The rate of more mild adverse effects is difficult to estimate, particularly when such effects do not result in hospital admission. We aimed to identify the rate and timing of adverse effects as reported by users querying symptoms on an internet search engine.

Methods

We identified queries made to Bing originating from users in the United States containing the word “colonoscopy” during a 12-month period and identified those queries in which the timing of colonoscopy could be estimated. We then identified queries from those same users for medical symptoms during the time span from 5 days before through 30 days after the colonoscopy date.

Results

Of 641,223 users mentioning colonoscopy, 7013 (1.1%) had a query that enabled identification of their colonoscopy date. The majority of queries about colonoscopy preceded the procedure, and concerned diet. 28% of colonoscopy-related queries were made afterwards, and included queries about diarrhea and cramps, with 2.6% of users querying respiratory symptoms after the procedure, including cough (1.2%) and pneumonia (0.6%). Respiratory symptoms rose significantly at days 7–10 after the colonoscopy.

Conclusions

Internet search queries for respiratory symptoms rose approximately one week after queries relating to colonoscopy, raising the possibility that such symptoms are an under-reported late adverse effect of the procedure. Given the widespread use of colonoscopy as a screening modality and the rise of anesthesia-assisted colonoscopy in the United States in recent years, this signal is of potential public health concern.

Additional value of linked color imaging in colonoscopy: a retrospective study

Background and study aims  Linked color imaging (LCI), a newly developed optical modality, enhances mucosal surface contrast. We aimed to evaluate the efficacy and feasibility of insertion-phase LCI in terms of additional benefit of colorectal polyp detection over that obtained with white light imaging (WLI). Patients and methods  We consecutively enrolled eligible patients from November 2017 to June 2018. During colonoscopy, LCI or WLI was alternatively applied on scope insertion and LCI was applied on scope withdrawal. Patients were divided into two groups according to the protocolized difference of imaging modality used in the scope insertion phase (LCI and WLI groups). Group differences in clinical outcomes were evaluated. Results  A total of 138 patients were enrolled in this study, with equal numbers of patients assigned to the LCI and WLI groups. Most of the lesions located in the proximal colon were detected during the withdrawal phase, without a difference in proportions between the two groups. However, in the LCI group, eight of 49 lesions (16 %) located in the sigmoid and rectosigmoid colon were only detected during the insertion phase, and no such lesions (0 %) were detected during the insertion phase in the WLI group ( P  = 0.045). Conclusions  This study showed the efficacy and feasibility of LCI in improving colorectal polyp detection in the sigmoid colon, especially during insertion. Further studies are warranted to validate the results of our single-center study.

Risk of Renal Injury After the Use of Polyethylene Glycol for Outpatient Colonoscopy: A Prospective Observational Study

GOAL

The goal of this study was to estimate the risk of renal injury after the use of 3-L polyethylene glycol (PEG) before outpatient colonoscopy.

BACKGROUND

Population-based studies showed that the use of PEG was associated with renal injury, but this association has not been confirmed by prospective study.

STUDY

Patients ≥40 years of age with an estimated glomerular filtration rate ≥30 mL/min were screened for enrollment. Laboratory data were collected before, during, and after the colonoscopies. Patients with a ≥30% increase in baseline serum creatinine levels were followed until a peak level was detected. Renal injury included acute renal dysfunction (ARD) and acute kidney injury (AKI), defined as a 30% to 49% increase and ≥50% increase in creatinine levels compared with the baseline, respectively.

RESULTS

A total of 1163 patients (mean age, 55.7 y) completed the study. Baseline and first postcolonoscopy laboratory data were obtained an average of 17.0 days before and 17.3 days after the colonoscopies were performed, respectively. Renal injury was identified in 32 patients; 26 patients (2.2%) had ARD, and 6 patients (0.5%) had AKI. All patients with renal injury recovered fully during follow-up. In the subgroup analysis, the use of nonsteroidal anti-inflammatory drugs (NSAIDs) before colonoscopy was statistically associated with the development of AKI (odds ratio, 6.5; 95% confidence interval, 1.2-35.5; P=0.03).

CONCLUSIONS

This prospective study showed that the use of PEG was associated with a small risk of renal injury. NSAIDs use was statistically associated with AKI in the context of colonoscopy for which PEG was used for bowel preparation.

Pre-diagnostic colonoscopies reduce cancer mortality - results from linked population-based data in South Australia

Background

To investigate the association between pre-diagnostic colonoscopy and colorectal cancer mortality in South Australia.

Methods

Colonoscopy histories were obtained for colorectal cancer patients diagnosed in 2003–2013 using linked Medical Benefits Schedule (MBS) claims, hospital-inpatient and cancer-registry data. Colonoscopy histories included the year of colonoscopy, numbers of examinations, and the time from first colonoscopy to diagnosis. Histories of multiple exposures to colonoscopies, and exposures of greater than a year from initial colonoscopy to diagnosis, were regarded as indicators of screening or surveillance activity. Colonoscopies occurring within one year of diagnosis were regarded as more likely to be a response to cancer symptoms than those occurring > 1 year before diagnosis. Associations between colonoscopy history and post-diagnostic survival were analysed using sub-hazard ratios (SHRs) from competing risk regression adjusted for socio-demographic and cancer characteristics.

Results

Having pre-diagnostic colonoscopy was associated with an unadjusted reduction in risk of colorectal cancer death of 17% (SHR: 0.83, 95% CI 0.78–0.89). After adjusting for time period and sociodemographic characteristics, the risk of colorectal cancer death reduced by 17% for one pre-diagnostic colonoscopy examination; 27% for two pre-diagnostic colonoscopy examinations; and 45% for three or more pre-diagnostic colonoscopy examinations. Those with a time of over one year from first colonoscopy in the study window to diagnosis, when compared with less than one year, had a 17% lower risk of colorectal cancer death in this adjusted analysis. These reductions were substantially reduced or eliminated when also adjusting for less advanced stage.

Conclusions

Pre-diagnostic colonoscopy, and more so, multiple colonoscopies and first colonoscopy occurring over one year from initial colonoscopy to diagnosis, were associated with longer survival post diagnosis. This was largely explained by less advanced cancer stage at the time of diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6092-4) contains supplementary material, which is available to authorized users.

Screening flexible sigmoidoscopy versus colonoscopy for reduction of colorectal cancer mortality

PURPOSE

Colonoscopy and flexible sigmoidoscopy are both recommended colorectal cancer (CRC) screening strategies, but their relative effectiveness is unclear. We sought to evaluate the ability of each of these two modalities to reduce CRC mortality.

METHODS

We conducted a case-control study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Cases were persons aged 70-85 years who died of CRC and were matched to up to three non-CRC controls. Receipt of endoscopy was ascertained from Medicare claims and endoscopy indication assigned using a validated algorithm. Conditional logistic regression models were developed to estimate the association between screening colonoscopy or sigmoidoscopy and CRC mortality. We conducted secondary analyses by race, sex, and endoscopist characteristics, and with varying duration of the look-back period.

RESULTS

In the initial analysis using all available look-back years, screening flexible sigmoidoscopy was associated with a 35% reduction in CRC mortality (OR 0.65, 95% CI 0.48, 0.89), while screening colonoscopy was associated with a 74% reduction (OR 0.26, 95% CI 0.23, 0.30). Sigmoidoscopy was not associated with any reduction in proximal CRC mortality. The association between colonoscopy and reduced CRC mortality was stronger in the distal than the proximal colon. Results were similar in analyses using a 5-year look-back period.

CONCLUSIONS

Screening colonoscopy was associated with greater reductions in CRC mortality than screening sigmoidoscopy, and with a greater reduction in the distal than the proximal colon. These results provide additional information on the relative benefits of screening for CRC with sigmoidoscopy and colonoscopy.

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.

Defining adenoma detection rate benchmarks in average-risk male veterans

BACKGROUND AND AIMS

Veterans have higher prevalence of colorectal neoplasia than non-veterans; however, it is not known whether specific Veterans Affairs (VA) adenoma detection rate (ADR) benchmarks are required. We compared ADRs of a group of endoscopists for colonoscopies performed at a VA center with their ADRs at a non-VA academic medical center.

METHODS

This was a retrospective review of screening colonoscopies performed by endoscopists who practice at the Indianapolis VA and Indiana University (IU). Patients were average-risk men aged 50 years or older. ADR, proximal ADR, advanced ADR, and adenomas per colonoscopy were compared between IU and the VA groups.

RESULTS

Six endoscopists performed screening colonoscopies at both locations during the study period (470 at IU vs 608 at the VA). The overall ADR was not significantly different between IU and the VA (58% vs 61%; P = .21). Advanced neoplasia detection rate (13% vs 17%; P = .46), proximal ADR (46% vs 47%; P = .31), and adenomas per colonoscopy (1.59 vs 1.84; P = .24) were not significantly different. There were no significant differences in cecal intubation rate (100% vs 99%; P = .13) or withdrawal time (10.9 vs 11.1 min; P = .28). In regression analysis, there was significant correlation between the attending-specific ADRs at IU and the VA (P = .041, r² = 0.69).

CONCLUSIONS

In this study of average-risk men undergoing screening colonoscopies by the same group of endoscopists, the ADRs of VA and non-VA colonoscopies were not significantly different. This suggests that a VA-specific ADR target is not required for endoscopists with high ADRs.

Colorectal Cancer Screening: Is Colonoscopy the Best Option?

Colorectal cancer is the second leading cause of cancer death in the United States. Prospective studies demonstrate that colorectal cancer screening reduces incidence and mortality, but uptake remains suboptimal. More than a third of age-eligible Americans are not up to date on screening. There are several available screening tests, which may cause primary care providers to ponder which is the best test. This article provides an overview of the available test options and the evidence for each; a summary of major guidelines; and a comparison of the two most widely used tests, colonoscopy and fecal immunochemical testing.

Clinical significance of colorectal polyp detection on colonoscopy insertion

Background

Colorectal lesions are generally evaluated during the withdrawal phase of colonoscopy. Minimising the risk of missed lesions is crucial to determine an appropriate future surveillance colonoscopy interval.

Objective

This study aimed to evaluate the clinical significance of detecting sigmoid colon lesions during the insertion phase.

Methods

This retrospective study included 172 consecutive patients undergoing colonoscopy between October 2017 and April 2018. The total number of detected polyps, mean polyps per procedure, mean polyps per positive procedure, and histological and clinical characteristics of detected lesions were recorded. The primary endpoint was the difference in sigmoid colon polyp detection rates during insertion and withdrawal.

Results

A total of 172 colonoscopies were performed for each patient and 322 lesions were detected. Sixty-two (19%) polyps were detected during insertion, 312 (97%) during withdrawal, and 52 (16%) during both insertion and withdrawal. Although all polyps except for those in the sigmoid colon could be detected during withdrawal, 10 of 87 (11%) polyps in the sigmoid colon could only be detected during insertion.

Conclusions

In this study, attempts to detect polyps, even in the insertion phase, showed the clinical significance to decrease the risk of missed adenomatous polyps in the sigmoid colon.

Molecular mechanisms of the preventable causes of cancer in the United States

Annually, there are 1.6 million new cases of cancer and nearly 600,000 cancer deaths in the United States alone. The public health burden associated with these numbers has motivated enormous research efforts into understanding the root causes of cancer. These efforts have led to the recognition that between 40% and 45% of cancers are associated with preventable risk factors and, importantly, have identified specific molecular mechanisms by which these exposures modify human physiology to induce or promote cancer. The increasingly refined knowledge of these mechanisms, which we summarize here, emphasizes the need for greater efforts toward primary cancer prevention through mitigation of modifiable risk factors. It also suggests exploitable avenues for improved secondary prevention (which includes the development of therapeutics designed for cancer interception and enhanced techniques for noninvasive screening and early detection) based on detailed knowledge of early neoplastic pathobiology. Such efforts would complement the current emphasis on the development of therapeutic approaches to treat established cancers and are likely to result in far greater gains in reducing morbidity and mortality.