Previous Negative Colonoscopy Research Articles

Preventable Predictive Factors of Post-colonoscopy Colorectal Cancer in Inflammatory Bowel Disease.

Post-colonoscopy colorectal cancer [PCCRC] is a colorectal cancer [CRC] diagnosed after a colonoscopy in which no cancer was detected [index colonoscopy]. Although the overall cumulative rates of PCCRC are low in both the general population and inflammatory bowel disease [IBD] patients, the overall incidence of PCCRC in IBD is greater than that documented in the general population. This study aimed to identify the index colonoscopy-related factors and patients' characteristics influencing IBD-associated PCCRC development. We carried out an observational, retrospective study in which IBD-associated PCCRCs were diagnosed between 2010 and 2023. The PCCRC group was compared with a control cohort of IBD patients without CRC, matched 1:1 by several demographic and clinical features as well as characteristics of index colonoscopy, to minimise selection bias. Among 61 CRCs identified, 37 [61%] were PCCRC. Twelve of the 37 [32%] PCCRC were diagnosed within 12 months after the previous negative colonoscopy, 15 [41%] within 12-36 months, and 10 [27%] within 36-60 months. In the multivariate analysis, the inadequate bowel preparation of the index colonoscopy (odds ratio [OR]: 5.9; 95% confidence interval [CI]: 11.1-31.4) and the presence of high-risk factors for CRC [OR: 24.03; 95% CI: 3.1-187.8] were independently associated with PCCRC. Conversely, prior exposure to immunosuppressors or biologics [OR: 0.17; 95% CI: 0.03-0.83] and random biopsies sampling at index colonoscopy [OR: 0.19; 95% CI: 0.04-0.85] were inversely associated with PCCRC. More than 50% of CRCs in our population were PCCRC. PCCRCs were associated with previous inadequate cleansing and occurred more frequently in high-risk patients.

P215 Mir-135b, an Early Biomarker of Sporadic and IBD-Related Colorectal Carcinogenetic Progression

Abstract Background Although the rates of IBD-related-CRC are decreasing over time, CRC is still a leading cause of mortality and reason for colectomy in patients with IBD. Among the different cancer biomarkers, microRNAs (miRs) have emerged as noninvasive tools for diagnosis, monitoring, and prognosis in tissues and biofluids of patients with IBD. Therefore, we aimed to investigate the role of miRs in the development and natural course of IBD-related CRC, in order to identify potential early biomarkers for IBD-related CRC screening and progression. Methods The cases were retrospectively collected from the archives of the Surgical Pathology and Cytopathology Unit at the University of Padua. We analysed 9 miRs in colonic tissue specimens of IBD patients with adenoma or dysplasia, with IBD related-CRC, other than 2 control groups of patients with sporadic CRC and of healthy subjects (HC). In addition, we included tissue samples from a colonoscopy that patients with IBD with adenoma or dysplasia underwent some years before the development of mucosal lesions (from 2 to 5 years before), therefore without evidence of adenoma or dysplasia. Results were analyzed with ThermoFisher Connected™ Software and a p-value < 0.05 was considered significant. Results Compared to HC, all nine analysed miRs were significantly up-regulated in patients with sCRC, with IBD-related CRC and in IBD patients with adenoma. While, only 3 miRs (miR-135b, mir-21, miR-224) were significantly upregulated in IBD patients with dysplasia (and in their own controls) compared to HC (p<0.0001). Notably, no differences in miRs expression levels were found in patients with IBD-related CRC compared to those found in patients with sCRC. Among all miRs analyzed, only miR-135b and miR-21 resulted significantly up-regulated in patients with IBD. Considering the levels of miR-135b in the tissue samples of IBD patients, we observed an evident increasing trend going from tissue specimens without lesions to those with adenoma or dysplasia and then to those with neoplastic lesions. miR-21 was significantly upregulated in patients with IBD-related CRC compared to both IBD patients with adenoma and their own control samples from a previous negative colonoscopy (p=0.003 and p=0.006, respectively). Likewise, a significant difference in miR-21 levels was observed between patients with IBD-related CRC and those with dysplasia (p=0.02). Conclusion miR-21 and miR-135b are involved in the carcinogenesis process of patients with IBD. They could be potential candidate biomarkers for diagnostic purpose, prognostic and predictive stratification of patients.

Abstract IA007: Time to extend screening colonoscopy intervals? If so, by how much and for whom? Findings at 120,000 repeat screening colonoscopies conducted 10 or more years after a negative screening colonoscopy

Abstract Background: Screening colonoscopy effectively reduces colorectal cancer (CRC) incidence and mortality by enabling detection and removal of precancerous lesions. However, evidence for the optimal interval for colonoscopic screening is limited, making this a subject of debate. A systematic review and meta-analysis of 28 studies published in 2019 found that detection of advanced neoplasms (ADN) within 10 years after a negative index colonoscopy is rare.1 This suggests that 10 year intervals for screening colonoscopy, as currently recommended,2 may be adequate. However, evidence for defining screening colonoscopy intervals beyond ten years has remained very sparse. We aimed to assess the prevalence of advanced colorectal neoplasms (ADN) at least ten years after a negative screening colonoscopy in a very large cohort of repeat screening colonoscopy participants in Germany. Methods: We derived sex- and age-specific ADN prevalences based on 120,298 repeat screening colonoscopies (women, 60.1%) conducted at ages 65+ at least 10 years since previous negative colonoscopy and reported to the German screening colonoscopy registry in 2013-2019. The findings were compared to all screening colonoscopies conducted at ages 65+ in the same period (1.25 million) by calculating standardized prevalence ratios (SPRs). Results: ADN prevalences were 3.6% and 5.2% among women and men 10 years after a negative screening colonoscopy and gradually increased to 4.9% and 6.6%, respectively, ≥14 years after a negative colonoscopy, compared to 7.1 and 11.6%, respectively, among all screening colonoscopies conducted during the same time period. Prevalences increased with age in all groups, but were consistently much lower in repeat colonoscopies conducted 10 or more years after a negative colonoscopy than among all colonoscopies within each subgroup defined by sex and age (SPRs for CRC: 0.22-0.38 among women and 0.15-0.24 among men, respectively; SPRs for ADN: 0.49-0.62 among women and 0.50-0.56 among men, respectively). Conclusions: ADN prevalences at colonoscopies conducted 10 years after a negative screening colonoscopy as currently recommended are low. Sex and age, potentially along with additional criteria,3 could guide potential risk-adapted extension of screening intervals beyond 10 years.

Su1659 – Positive Faecal Occult Blood Test After a Previous Negative Colonoscopy - to Scope Or Not?

Su1659 – Positive Faecal Occult Blood Test After a Previous Negative Colonoscopy - to Scope Or Not?

Diabetes Mellitus and Age are Risk Factors of Interval Colon Cancer: A Case-Control Study

Background and Aims: Interval colorectal cancer (CRC) is largely related to a poor endoscopic performance or different biology in the development of the polyp. However, patient-related factors were less investigated for their association with interval cancer. We thus evaluated tumor and patient characteristics as predictors of interval cancer in a population from Israel. Methods: In this retrospective study, patients that were diagnosed with colon cancer in our institution and had 2 colonoscopies were included. Demographic parameters and tumor characteristics were compared between 84 cases with interval cancer, occurring 1–10 years after a negative colonoscopy, and 983 patients with primary CRC. In addition, patient-related features, including diabetes and diverticulosis, were compared between 51 patients with interval cancer after negative colonoscopy and 255 controls with no cancer and a previous negative colonoscopy. Results: Compared to “positive” controls with primary cancer, patients with interval cancer were older (age 71.3 vs. 67.6, p = 0.003), had proximal tumor location (57 vs. 34%, p < 0.001) and non-advanced (0–2) tumor staging (78.5 vs. 64.8%, p = 0.014). Compared with ­“negative” healthy controls, cases with interval cancer had only higher prevalence of diabetes (31 vs. 15%, p = 0.002). No significant differences were seen between patients with interval cancer occurring < 3 years and after 3–10 years. Conclusions: Patients with Interval cancer tend to be older and have diabetes. These patient groups should be more carefully or more frequently screened for pre-malignant lesions.

PTH-037 Do Patients with a Previous Negative Colonoscopy and Positive Fob Test Need a Bowel Cancer Screening Colonscopy?

IntroductionPatients with a positive faecal occult blood test invited for screening colonoscopy may have undergone previous colonoscopy. Excluding such patients from a repeat colonoscopy may reduce endoscopy waiting lists and...

Interval cancers after negative colonoscopy: population-based case-control study

ObjectiveThe risk of colorectal cancer after a previous negative colonoscopy is very low. Nevertheless, interval cancers occur. We aimed to assess the characteristics and predictors of interval cancers after negative...

Long-Term Risk of Colorectal Cancer After Negative Colonoscopy

Colonoscopy is thought to be a powerful and cost-effective tool to reduce colorectal cancer (CRC) incidence and mortality. Empirical evidence for overall and risk group-specific definition of screening intervals is sparse. We aimed to assess the risk of CRC according to time since negative colonoscopy, overall, and by sex, smoking, and family history of CRC, in a large population-based case-control study. In all, 1,945 patients with CRC and 2,399 population controls were recruited in 22 hospitals and through population registers in the Rhine-Neckar region of Germany from 2003 to 2007. Data on history of colonoscopy and important covariates were obtained by personal interviews and from medical records. Compared with people who had never undergone colonoscopy, people with a previous negative colonoscopy had a strongly reduced risk of CRC. Adjusted odds ratios for time windows of 1 to 2, 3 to 4, 5 to 9, 10 to 19, and 20+ years after negative colonoscopy were 0.14 (95% CI, 0.10 to 0.20), 0.12 (95% CI, 0.08 to 0.19), 0.26 (95% CI, 0.18 to 0.39), 0.28 (95% CI, 0.17 to 0.45), and 0.40 (95% CI, 0.24 to 0.66), respectively. Low risks even beyond 10 years after negative colonoscopy were observed for both left- and right-sided CRC and in all risk groups assessed except current smokers, who had a risk similar to that of never smokers with no previous colonoscopy 10 or more years after a negative colonoscopy. These results support suggestions that screening intervals for CRC screening by colonoscopy could be longer than the commonly recommended 10 years in most cases, perhaps even among men and people with a family history of CRC, but probably not among current smokers.

Low Risk of Colorectal Cancer and Advanced Adenomas More Than 10 Years After Negative Colonoscopy

Screening colonoscopy is an effective method to reduce the incidence of and mortality from colorectal cancer (CRC). There is little empirical evidence available about the optimal interval for screening, making this a subject of debate. We associated the prevalence of advanced colorectal neoplasms with time since negative colonoscopies. In a study of participants in the German colonoscopy screening program, we determined the prevalence of colorectal neoplasias detected at screening colonoscopy among subjects who had undergone a previous colonoscopy without detection of polyps (negative colonoscopy). Data were compared with that from subjects who had not received colonoscopies. No CRCs were detected in participants who had a previous negative colonoscopy an average of 11.9 years previously (n = 553), compared with the 8.4 CRC cases expected based on age- and gender-specific prevalences among participants who had not received a colonoscopy (n = 2701; standardized prevalence ratio [SPR] = 0.00; 95% confidence interval [CI]: 0.00-0.55). Prevalence of advanced adenoma was also much lower among subjects who had previous colonoscopies (SPR = 0.42; 95% CI: 0.25-0.68). Adjusted prevalence ratios (95% CIs) for detecting an advanced adenoma were 0.38 (95% CI: 0.16-0.90), 0.34 (95% CI: 0.15-0.74), 0.38 (95% CI: 0.16-0.90), and 0.53 (95% CI: 0.27-1.04) among participants with a negative colonoscopy conducted 1-5, 6-10, 11-15, and >16 years ago, respectively, compared to participants with no previous colonoscopy. The low risk of CRC and advanced adenomas after a negative colonoscopy supports suggestions that screening intervals be extended to > or =10 years.

Study supports 20-year interval for colonoscopy screening

Patients with a negative colonoscopy result might not need to have another colonoscopy for 20 years or more, suggests a population-based, case–control study (Gut 2006; 55: 1145–50). Hermann Brenner and colleagues (German Cancer Research Centre, Heidelberg, Germany) compared the adjusted relative risks of colorectal cancer in 380 patients who had a previous negative colonoscopy with those in 485 control patients who had not undergone previous colonoscopy, according to time since colonoscopy. Patients with previous negative colonoscopy had a 74% lower risk of colorectal cancer than did those without previous colonoscopy (adjusted odds ratio 0·26; 95% CI 0·16–0·40). The risk remained low even when the colonoscopy had been done 20 or more years previously, Brenner and colleagues report. “These fi ndings should have an impact on future screening guidelines”, says Brenner. “There are virtually no data available on colorectal-cancer risk beyond 10 years after a negative screening colonoscopy, which has hindered recommendations of longer screening intervals.” According to John Marshall (Georgetown University, Washington, DC, USA), this study suggests that patients who have even one negative colonoscopy at some point in their lives have a low risk of developing colon cancer and that this conclusion seems justifi ed by the data. However, he cautions that only fi ve (1%) patients and 13 (3%) controls fell into the “over 20-year” category, on which researchers base part of their conclusions. “We must remember that the majority of patients diagnosed with colon cancer have later-stage disease, suggesting that we are failing to detect earlystage colon cancer in most patients”, says Marshall. “While one colonoscopy is better than none, one should not conclude from this study that one, and only one, colonoscopy will prevent colon-cancer deaths.”

Gastrointestinal Involvement of Mantle Cell Lymphoma in a Patient with Previous Negative Colonoscopy

Gastrointestinal Involvement of Mantle Cell Lymphoma in a Patient with Previous Negative Colonoscopy