Post-colonoscopy colorectal cancer incidence.

Acetylsalicylic acid (ASA) has been linked to reduced incidence and mortality in colorectal cancer (CRC), although its sex-specific effects remain unclear. Post-colonoscopy colorectal cancer (PCCRC), is a CRC diagnosed after a colonoscopy negative for cancer. The aim of this study was to explore the sex-specific effects of ASA on cancer-specific mortality risk in in CRC in general and in PCCRC specifically. This retrospective register-based study analyzed the conditional CRC-specific survival in 22 270 Swedish patients who underwent colonoscopy, including 1647 PCCRCs. The analyses were stratified on sex. ASA use was associated with lower CRC mortality in men but not in women, hazard ratio (HR) = 0.85, 95% confidence interval (CI): 0.72-0.99, P = 0.043 for men and HR = 1.13, 95% CI: 0.93-1.37, P = 0.230 for women. Notably, ASA use in women, but not in men, with PCCRC was linked to increased mortality risk; HR for interaction PCCRC × ASA in women = 1.60, 95% CI: 1.02-2.51, P = 0.040 and HR for interaction PCCRC × ASA in men = 0.81, 95% CI: 0.50-1.32, P = 0.41. These exploratory analyses suggest sex-specific differences in the effect of ASA on CRC outcomes, particularly in PCCRC. Further research is needed to elucidate underlying the mechanisms and optimize chemopreventive strategies.

Mo1682 INTERVAL POST-COLONOSCOPY COLORECTAL CANCER IN A REFERRAL CENTER COHORT: A GOOD REASON TO IMPROVE THE COLONOSCOPY QUALITY

INTRODUCTION: The serrated pathway may account for a significant proportion of colorectal cancer (CRC). Achieving adequate serrated polyp detection rates (SDR) may reduce the incidence of post colonoscopy CRC (PCCRC). We used data from the New Hampshire Colonoscopy Registry (NHCR) to determine if exams performed by endoscopists who have a clinically significant serrated polyp detection rate (CSSDR) of 7% or greater, proposed by Anderson/Butterly (GIE 2017), had a reduced incidence of PCCRC. In addition, we compared CSSDR to the adenoma detection rate (ADR), the currently used benchmark. METHODS: We defined PCCRC as any CRC diagnosed between 6 and 36 months after an exam with an adenoma on index and between 6 and 60 months following a normal exam. Exclusion criteria were any CRC diagnosed at index or within 3 months, incomplete exams, IBD, and genetic syndromes. Clinically significant serrated polyps (CSSP) were defined as any sessile serrated polyp, traditional serrated adenoma, serrated polyp >1 cm anywhere in the colon and any serrated polyp >5 mm proximal to the sigmoid. CSSDR was defined as number of screening exams with at least one CSSP divided by all screening exams. The exposure variable was a CSSDR of 7% and adenoma detection rate of 25%. Cox regression was used to model the risk of PCCRC in terms of the covariates at index exam. Covariates were age, BMI, smoking, index findings (large serrated polyp, advanced adenoma or any adenoma), followup time (months), bowel prep quality, having more than 1 surveillance exam and family history of CRC. We also compared receiver operating characteristics (ROC) for CSSDR 7% to an ADR 25% using probabilities derived from a logistic regression analysis. RESULTS: In our sample (142,950 index exams) 75 CRCs were diagnosed during the 6–60 month period (45 CRCs diagnosed between 6–36 months) after the index exam. The hazard ratio (HR) for CSSDR of 7% (HR = 0.37 95% CI 0.17–0.83) was similar to that for an ADR of 25% (HR = 0.45 95% 0.23–0.89) (Table 1). The ROCs were similar for CSSDR and ADR and the combination of the 2 rates did not alter the ROC (Table 2). CONCLUSION: Having an exam performed by an endoscopist with a CSSDR of 7% or greater was associated with a decrease incidence of PCCRC (HR = 0.37). The performance of CSSDR and ADR for PCCRC incidence were similar. These data suggest that a CSSDR of 7% or greater may be associated with lower PCCRC rates. However, it may not add an information to that provided by the current primary colonoscopy benchmark, ADR.

Characteristics and Survival of Patients With Inflammatory Bowel Disease and Postcolonoscopy Colorectal Cancers

Background: Early onset colorectal cancer is defined as cancer diagnosed before the age of 50 years. Its incidence has been increasing worldwide in recent years. The aim of our study was to assess the real-life incidence of early onset colorectal cancer, advanced neoplasias (colorectal cancer and/or advanced adenoma) and all neoplastic lesions in total in a single non-university endoscopic center. Methods: We retrospectively evaluated the incidence of all neoplastic lesions, advanced neoplasias and colorectal cancer in population under 50 years of age compared to population aged 50 years and older. We collected the data from all colonoscopic examinations performed in non-university Hospital Frydek-Mistek from January 2012 to the end of June 2021. Results: During the observed period, 18,257 colonoscopic examinations were performed in total, 14,728 in population aged 50 years and older and 3,529 in population under 50 years of age. In our study, there were 29 patients with early onset colorectal cancer (5.21% of 557 total) and 106 patients with early onset advanced neoplasias (4.47% of 2,371 total). The incidence of colorectal cancer, advanced neoplasias and all neoplasias was higher among men in older study group, but the incidence of early onset colorectal cancer and advanced neoplasias in younger group did not significantly differ between the sexes, only the incidence of all neoplastic lesions was also higher among men. Positive family history of colorectal cancer was not significantly associated with risk of early onset colorectal cancer (p = 0.316) or early onset advanced neoplasia (p = 0.323) in our study. Conclusions: Early onset colorectal cancer represented 5.21% of all colorectal cancers diagnosed during the study period. The incidence of colorectal cancer and advanced neoplasias in population under 50 years of age was 0.82% and 3.00%, compared with 3.59% and 15.38% in older population. In contrast to older population, the incidence of early onset colorectal cancer and advanced neoplasias did not differ between the sexes. Keywords diagnosis, colorectal cancer, screening, population groups

Mo1662 PATIENT AND ENDOSCOPIC CHARACTERISTICS OF POST-COLONOSCOPY COLON CANCER: A CASE-CONTROL STUDY

Introduction Colorectal cancer (CRC) is the third most common cancer globally and the third most common cause of cancer death. Early diagnosis at stages where disease can be treated, significantly improves survival rates justifying the need for CRC screening programs by ‘gold standard’ colonoscopy. Given the concern for significant numbers of missed lesions, the new JAG Global Rating Scale (GRS) requires all endoscopy units to develop an audit for post-colonoscopy colorectal cancer (PCCRC). Our aim was to provide a template for performing this audit at a major teaching hospital. Methods We retrospectively reviewed our electronic patient records and collected data on all new CRC diagnoses made over a three-year period (1 st September 2014 – 31 st August 2017). We looked for evidence of colonoscopy performed in the three years prior to diagnosis and applied the following exclusion criteria: No colonoscopy within the 3 years prior to diagnosis Diagnosis of CRC made at different hospital hindering access to patient records Previous flexible sigmoidoscopy only and subsequent CRC diagnosis in transverse/ascending colon Unsatisfactory bowel preparation necessitating repeat endoscopy Alternative investigation/referral arranged by endoscopist (e.g. due to technical difficulty leading to incomplete endoscopy procedure). PCCRC rate was defined as the proportion of PCCRC diagnoses amongst all CRC cases. For CRC cases, we also analysed patient demographics, timeframe between colonoscopies and individual endoscopist PCCRC rate. Results Out of a total 944 CRC cases, 691 were eligible for analysis (Figure 1). There were a total of 12 cases of PCCRC, giving our hospital a PCCRC of 1.74%. The average age of patients with a PCCRC diagnosis was 65.25 years (29–80). The average time between initial and diagnostic colonoscopies in PCCRC cases was 14.33% months (range, 1–34) with initial-to-diagnostic colonoscopies separated by 24 months in 2 cases (16.67%). Physician endoscopist miss rate ranged from 0.11%–0.21%. Conclusions Results from our audit show our hospital is within the BSG, JAG and the Association of Coloproctology of Great Britain and Ireland (ACPGBI) quality assurance target of

PurposeStudies suggest that patients with type two diabetes mellitus (T2D) may be at increased risk of post-colonoscopy colorectal cancer (PCCRC). We investigated clinical and molecular characteristics and survival of T2D patients with PCCRC to elucidate how T2D-related PCCRC may arise.MethodsWe identified T2D patients with colorectal cancer (CRC) from 1995 to 2015 and computed prevalence ratios (PRs) comparing clinical and molecular characteristics of CRC in T2D patients with PCCRC vs. in T2D patients with colonoscopy-detected CRC (dCRC). We also followed T2D patients from the diagnosis of PCCRC/dCRC until death, emigration, or study end and compared mortality using Cox-proportional hazards regression models adjusted for sex, age, year of CRC diagnosis, and CRC stage.ResultsCompared with dCRC, PCCRC was associated with a higher prevalence of proximal CRCs (54% vs. 40%; PR: 1.43, 95% confidence interval [CI] 1.27–1.62) in T2D patients. We found no difference between PCCRC vs. dCRC for CRC stage, histology, and mismatch repair status. The proportion of CRCs that could be categorized as PCCRC decreased over time. Within one year after CRC, 63% of PCCRC vs. 78% of dCRC patients were alive (hazard ratio [HR] 1.85 [95% CI 1.47–2.31]). Within five years after CRC, 44% of PCCRC vs. 54% of dCRC patients were still alive (HR 1.44 [95% CI 1.11–1.87]).ConclusionThe increased prevalence of proximally located PCCRCs and the poorer survival may suggest overlooked colorectal lesions as a predominant explanation for T2D-related PCCRC, although altered tumor progression cannot be ruled out.

Risk of Developing Proximal Versus Distal Colorectal Cancer After a Negative Colonoscopy: A Population-Based Study

Endoscopist adenomas-per-colonoscopy detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

Introduction Colorectal cancer (CRC) diagnosed following a colonoscopy in which no CRC is found is termed Post-Colonoscopy CRC (PCCRC). The World Endoscopy Organisation (WEO) consensus statements recommend review of individual PCCRC cases, including categorisation of cases into interval/non-interval CRCs, and root cause analysis (RCA) to determine most plausible explanation. Our study aim was to test the usability, reproducibility and outcomes of the WEO categorisation. Methods All CRC cases diagnosed from January 2015 to December 2016 in a single NHS trust were identified. Each was cross-referenced with local endoscopy and pathology databases. Cases where non-diagnostic colonoscopy was performed prior to CRC diagnosis were included. All colonoscopies going back to 2007 (when endoscopy reporting system introduced) were reviewed. Each CRC was entered into a spreadsheet, with headings based on WEO RCA checklist for PCCRCs. We performed 2 separate assessments: (1) RCA to identify WEO most plausible explanation for PCCRC; and (2) WEO PCCRC subtype categorisation, which looks at screening/surveillance intervals (table 1). Inter-observer agreement was measured using Cohen’s kappa (k). Cases with inter-rater variation were analysed further using patient notes and then discussed by a panel to determine causes of variation and attempt to reach consensus. Results Among 527 patients with CRC, 48 PCCRCs were identified. In 32 cases, the prior colonoscopy occurred within 4 years of CRC diagnosis (table 1). Median age was 73 (range 48–93), 56% of cases were male. Consistent most plausible explanation was found in 31/32 (97%) cases, showing almost perfect agreement (k=0.94). Categorisation into interval and non-interval types was consistent in 37/48 (77%) cases, showing substantial agreement (k=0.67). Following panel discussion, consensus was reached for most plausible explanation and categorisation of PCCRC in all cases. 66% of PCCRCs within 4 years of diagnosis were attributed to ‘possible missed lesion, prior examination adequate’. 73% of cases were categorised as Non-interval Type B or C. Full results are in table 1. Conclusion Using readily available data, PCCRC cases can be categorised by most plausible aetiology with almost perfect inter-rater agreement. Categorisation of PCCRC subtype was more challenging, reflecting uncertainties in surveillance intervals and endoscopic plans. Further discussion, with additional clinical information, led to agreement in all cases. The majority of PCCRC cases were categorised as ‘probable missed lesions following an adequate colonoscopy’. The high number of Non-interval type B PCCRCs suggests a significant proportion of PCCRC cases could be avoided with adherence to recommended surveillance intervals.

Colorectal cancer (CRC) diagnosed following a cancer-negative colonoscopy is termed post-colonoscopy CRC (PCCRC). In addition to calculating PCCRC rates, the World Endoscopy Organization (WEO) recommends review of individual PCCRC cases, including categorization into interval/non-interval PCCRCs, and root cause analysis to determine the most plausible explanation. We aimed to test the usability, reproducibility, and outcomes of the WEO algorithms. All CRC cases diagnosed from January 2015 to December 2016 in a single organization were cross referenced with local endoscopy and pathology databases to identify cases of PCCRC. We assessed: 1) WEO most plausible explanation for PCCRC; and 2) WEO PCCRC interval/non-interval subtype categorization. Interobserver agreement was measured using Cohen's kappa (κ). Cases with interobserver variation underwent panel discussion to reach consensus. Among 527 patients with CRC, 48 PCCRCs were identified. A consistent most plausible explanation was found in 97 % of cases, showing almost perfect agreement (κ = 0.94). Most PCCRCs (66 %) were attributed to "possible missed lesion, prior examination adequate." Interval/non-interval categorization was consistent in 77 %, showing substantial agreement (κ = 0.67). Following panel discussion, consensus was reached in all cases. Overall, 15 % were categorized as interval and 85 % as non-interval PCCRCs (12 % type A, 31 % type B, and 42 % type C). Review of PCCRC cases using WEO recommendations was performed accurately at a local level using readily available clinical information. The high number of non-interval type B PCCRCs suggests a significant proportion of PCCRCs could be avoided by better adherence to recommended surveillance intervals.

Introduction: Colorectal cancer is one of the leading cancers in terms of incidence and mortality worldwide, including in Indonesia. Type 2 diabetes mellitus (T2DM) is increasingly recognized as a significant risk factor for the development of colorectal cancer, with underlying mechanisms involving insulin resistance, hyperinsulinemia, impaired glucose metabolism, and chronic inflammation that promote malignant transformation. While international epidemiological studies have demonstrated an increased risk of colorectal cancer among patients with T2DM, local data in Indonesia, particularly in Medan, remain limited. Objective: This study aimed to analyze the association between type 2 diabetes mellitus and the incidence of colorectal cancer, as well as to assess the relationship between glycemic parameters (random blood glucose, fasting blood glucose, 2-hour postprandial glucose, and HbA1c) and the progression of colorectal cancer at RSUP H. Adam Malik Medan. Methods: This was an analytical observational study with a cross-sectional design, involving 61 colorectal cancer patients treated at the digestive surgery division of RSUP H. Adam Malik Medan from March to June 2025. Data were collected through consecutive sampling and included demographic characteristics (age, gender), history of T2DM, laboratory results for random blood glucose, fasting blood glucose, 2-hour postprandial glucose, HbA1c, and cancer stage. Statistical analysis used the chi-square test to evaluate the association between T2DM and glycemic parameters with the incidence and progression of colorectal cancer. Results: Most colorectal cancer patients were male, with the largest age group being 50–69 years. Of all patients, 37.7% had a history of type 2 diabetes mellitus. There was a statistically significant association between T2DM and the incidence of colorectal cancer (p=0.042). Furthermore, high glycemic parameters—random blood glucose ≥200 mg/dL, fasting blood glucose ≥126 mg/dL, 2-hour postprandial glucose ≥200 mg/dL, and HbA1c ≥6.5%—were significantly more common in patients with advanced-stage colorectal cancer compared to early-stage cases (p<0.05 for all parameters). The majority of patients had adenocarcinoma as the histopathological type. Conclusion: Type 2 diabetes mellitus is a significant risk factor for the incidence of colorectal cancer. Poor glycemic control is associated with the progression of colorectal cancer. Most colorectal cancer patients were male and aged 50–69 years, with adenocarcinoma as the most common histopathological type. These findings highlight the importance of optimal metabolic control in diabetic patients to reduce the risk and progression of colorectal cancer.

Colorectal cancer has a high worldwide incidence. Japan, a country that is geographically and culturally similar to the Republic of Korea (here after Korea), has recently reported a decreasing trend in the incidence of colorectal cancer. However, Korea had the highest incidence of colorectal cancer among Asian countries in 2012. Our aim was to observe the changing trends in incidence and mortality of colorectal cancer in Korea and to compare them to those in Japan. Incidence data were collected from the Korean Central Cancer Registry and mortality data were collected from Korean Statistical Information Service. Incidence and mortality data on colorectal cancer in Japan were acquired from the National Cancer Center in Japan. Age-standardized incidence and mortality rates were determined based on Segi’s world population. Screening data from both countries were collected from the national cancer center in each country. In Korea, the age-standardized incidence rate of colorectal cancer in both sexes was 20.9 to 38.0 per 100,000 from 1999 to 2012 and the rate in males increased more dramatically than in females. In addition, the increase between 2002 and 2012 was first observed in the age group over 40. In Japan, the incidence of colorectal cancer has been more constant over recent years than in Korea. The age-standardized mortality rate of colorectal cancer in both sexes in Korea was 8.5 to 9.3 per 100,000 from 2000 to 2013, and the trend in mortality was constant during this period. In Japan, the mortality rate decreased slightly during the same period. Crude screening rates were increased overall in both Korea and Japan during the period studied. Since the incidence of colorectal cancer has increased in Korea, the control of this cancer is an important public health issue. As Japan has achieved a reduction in colorectal cancer, adjustment of Korea’s current systems for screening and treatment of colorectal cancer according to those of Japan may contribute to improved colorectal cancer control in Korea.

Background: Inflammation plays an important role in colorectal cancer formation, where colitis inflammatory cells can trigger the production of free radicals that interact with genes in carcinogenesis. Meanwhile, the colonic mucosal epithelium contains goblet cells that function to prevent inflammation. This study aims to examine the correlation between the number of goblet and inflammatory cells in the colon of patients with colorectal cancer, colitis, and healthy colon and their relationship with the incidence of colorectal cancer and colitis. Methods: Histopathological samples consisting of 30 healthy colons, 30 colons with colitis, and 31 colons with colorectal cancer were examined to obtain the average cell number in 10 or the entire field of view using a light microscope with 400 magnification. Using the Pearson correlation test and Multivariate Multinomial Logistic Regression, these samples were analyzed with SPSS version 26 for Windows. Results: Consequently, the results showed a weak but insignificant negative correlation between the number of goblet and inflammatory cells in the colon with colorectal cancer (r2=0.055; p=0.200), colitis (r2 = 0.002, p = 0.833), and healthy colon (r2 = 0.110, p = 0.073). The number of inflammatory cells is significantly associated with the incidence of colorectal cancer (OR=1.326; 95%CI=1.155-1.521; p=0.000) and colitis (OR=1.374; 95%CI=1.192-1.583; p=0.000) compared to normal colon. Conclusion: An increase in inflammatory cells is significantly associated with the incidence of colorectal cancer and colitis.