Long-term Risk Of Colorectal Cancer Research Articles

Risk of colorectal cancer and adenoma after an appendectomy: results from three large prospective cohort studies and meta-analysis.

The relationship between appendectomy and subsequent colorectal cancer risk remains unclear, and no study has examined its association with colorectal adenoma. We used data from three prospective cohorts: Health Professionals Follow-up Study, Nurses' Health Study (NHS), and NHSII. Appendectomy history was self-reported at baseline. Colorectal cancer risk was analyzed with Cox proportional hazard models among 224,109 participants followed up to 32years. Colorectal adenoma risk was evaluated among 157,490 participants with at least one lower gastrointestinal endoscopy during follow-up with logistic regression models accounting for repeated observations. We also performed a meta-analysis of cohort studies that examined association between appendectomy and colorectal cancer risk. We documented 3,384 colorectal cancers, 13,006 conventional adenomas, and 11,519 serrated polyps during the follow-up period. Compared to participants without appendectomy, those whoreported appendectomy history were not at higher risk of colorectal (HR [95% CI], 0.92 [0.84-1.00]), colon (0.92 [0.83-1.01]), or rectal (0.85 [0.70-1.03]) cancer. Similarly, appendectomy history was not associated with higher risk of conventional adenoma (OR [95% CI], 1.00 [0.97-1.02]), serrated polyp (0.97 [0.94-1.00]), or high-risk adenoma (0.96 [0.92-1.01]). The meta-analysis showed appendectomy was associated with a higher risk of colorectal cancer within a short time after the procedure (1.68 [1.01-2.81]), while the long-term risk was slightly inverse (0.94 [0.90-0.97]). We found no evidence of an association between appendectomy history and long-term risk of colorectal cancer or its precursors. The observed higher risk of colorectal cancer right after appendectomy in the first few years is likely due to reverse causation.

Effect of Low-Dose Aspirin on the Elderly.

Aspirin is a recognized and affordable antiplatelet medicine. Low amounts of aspirin have been used to prevent cardiovascular events, and it is still widely used for primary and secondary stroke prevention. The purpose of this review article is to evaluate the effects of using low doses of aspirin among elderly people. Although taking large dosages of aspirin (500 mg daily) reduces the long-term risk of colorectal cancer, its effectiveness for long-term prevention may be limited by adverse effects. Studies have assessed the relationship between aspirin dosage, incidence, and death in patients withcolorectal cancer. Research has indicated that those with diabetes mellitus have an increased risk of cardiovascular events. Low amounts of aspirin have been used to prevent cardiovascular events. However, there is uncertainty regarding the potential benefits and risks associated with preventing the development ofcardiovascular problems inindividuals with diabetes. The use of aspirin lowers the risk of occlusive vascular events but raises the possibility of bleeding. More attention should be paid to reducing inappropriate aspirin usage in light of its prevalence, particularly among older persons, as the substantial continuous usage of thisdrug increases the chances of bleeding.

S141 Long-Term Risk of Colorectal Cancer in Patients With Prediabetes : A Systematic Review and Meta-Analysis

Introduction: Prediabetes is often underdiagnosed and underreported due to its asymptomatic state in over 80% of individuals. Considering its role in promoting cancer incidence and limited evidence linking prediabetes and colorectal cancer (CRC), we conducted a meta-analysis to evaluate the incidence of colorectal cancer in people with prediabetes. (Figure) Methods: A comprehensive search through PubMed/Medline, Embase, Scopus, and Google Scholar was performed until June 1, 2022, to screen for studies reporting colorectal cancer incidence/risk in prediabetics. Binary random-effects models were used to perform meta-analysis and subgroup analyses. Sensitivity analysis was done using leave-one-out method. Results: Seven prospective and one retrospective study comprising 15 cohorts and a pooled number of 854876 cases and 2190511 controls were included in the analysis (2 Japan, 2 Korea, 1 Sweden, 1 UK, 1 China, and 1 USA). After combining all the studies the forest plots for adjusted analysis shows a significant increase in odds of having CRC with prediabetes - (OR 1.16; 1.08–1.25, p< 0.01) (fig 1b) and unadjusted analysis also shows a significant increase in odds of having CRC with prediabetes (OR 1.62; 1.35–1.95, p< 0.01) (fig 1a). Sensitivity analysis using the Leave-one-out method did confirm equivalent results (fig 1c). Heterogeneity analysis for adjusted OR had moderate heterogeneity with an overall I^2 of 56.06% with a p value < 0.01 and for unadjusted OR had considerable heterogeneity with an overall I^2 of 85.72% with a p value less than 0.01. Subgroup analysis based on type of study, the odds of developing colorectal cancer was higher in prospective studies (OR 1.175; 1.065-1.298)(p 0.001) than retrospective studies(OR 1.162; 1.033- 1.306)(p 0.012) .The odds of developing cancer was not significantly higher in ages >60(OR 1.446; 0.887-2.356)(p 0.139) compared to less than 60 years. The strongest association b/w Prediabetes and CRC was found on a median 5-10 years(aOR 1.257; 1.029-1.534)(p 0.025) follow-up compared to < 5 years and 10 years and higher. Conclusion: This study showed nearly 16% higher long-term risk of colorectal cancer in patients with prediabetes. Lifestyle modifications like weight loss, proper diet, and exercise are essential to control prediabetes. This study further warrants a specific prediabetes screening for patients already at high risk of colorectal cancer with other risk factors. These strides would help subsequently lower the disease burden, and associated morbidity/mortality.Figure 1.: Forest Plot: Long-term Risk of Colorectal Cancer in Patients with Prediabetes vs Normoglycemia

Colonoscopy and polypectomy: beside age, size of polyps main factor for long-term risk of colorectal cancer in a screening population

PurposeDespite national and international guideline recommendations, few studies have been conducted to estimate the impact of colonoscopy screening on long-term colorectal cancer incidence. Aim of this study was to determine the long-term impact of a full colonoscopy with polypectomy on colorectal cancer incidence in a large screening population.MethodsIn this prospective observational cohort study, a total of 10,947 colonoscopy screening participants from within the scope of the Munich Cancer Registry were consecutively recruited from participating gastroenterology practices and their subsequent colorectal cancer incidence assessed. Predictive factors associated with colorectal cancer were also evaluated in univariate and multivariate analyses.ResultsAfter a median follow-up of 14.24 years (95% CI [14.21–14.25]), 93 colorectal cancer cases were observed. This is equivalent to a truncated age-standardized rate of 69.0 (95% CI [43.3–94.7]) for male and 43.4 (95% CI [29.4–57.5]) for female participants (≥ 50 years at colonoscopy). The ratio of this observed to the expected rate from cancer registry data showed a 67% decrease in colorectal cancer incidence in the male and 65% in the female participants (p < 0.0001). In multivariate analysis of screening patients, age at screening (p < 0.0001) was the main predictive factor for colorectal cancer. In the subgroup with positive polyp findings, age (p < 0.0001) and the polyp size (p = 0.0002) were associated with colorectal cancer.ConclusionThese results underline the significance of a full colonoscopy screening combined with polypectomy in reducing the total disease burden of colorectal cancer.

Does Colon Polyp Surveillance Improve Patient Outcomes?

Colon polyp surveillance now accounts for 25% of all colonoscopies performed. The evidence that colonoscopy surveillance reduces colorectal cancer (CRC) incidence or mortality is weak. The biology of the baseline lesions and quality of the baseline exam are two primary factors contributing to post-colonoscopy CRC. Prior recommendations for surveillance were based largely on the likelihood that patients with adenomas would develop advanced adenomas, a surrogate for CRC. There is now evidence that baseline colonoscopy findings are strongly associated with the risk of incidence or death from CRC. This evidence provides a basis for updated evidence-based recommendations for surveillance. In addition, there is also growing evidence that the quality of the baseline exam is an important predictor of the likelihood of developing post-colonoscopy CRC.

Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population

The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings. Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders. Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18). With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

1130 Bariatric Surgery Is Associated With a Recent Temporal Increase in Colorectal Cancer Resections, Most Pronounced in Adults &lt;50 Years of Age: A 2006-2013 National Analysis

INTRODUCTION: The incidence rates of early-age onset colorectal cancer (CRC) are rapidly rising in the United States. In parallel, evolving evidence suggests an unexpected increase in long-term risk of CRC after bariatric surgery (BRS). BRS utilization expanded in the past three decades, however limited knowledge exists regarding the impact of BRS on age-stratified trends of obesity-related gastrointestinal cancers (OGCs) including that of CRC. METHODS: We queried the 2006-2013 National Inpatient Sample (NIS), the largest publicly available all-payer data repository, to identify patients who underwent resections for OGCs. We investigated patients with morbid obesity (body mass index ≥ 40 kg/m2) and those with prior BRS. In a separate analysis, we also looked at non-BRS/non-obese individuals. We divided OGCs into two groups: CRC and non-CRC OGCs (esophageal, gastric, liver, gallbladder and pancreatic cancers combined). Joinpoint regression analysis was used to calculate the average annual percent change (AAPC) in patients undergoing cancers resections across age groups (age &lt; 50 and ≥ 50 years old). RESULTS: We identified 28,041 patients with morbid obesity and 2,238 patients with a prior BRS who had resections for OGCs in 2006-2013. BRS patients were younger, with more females and fewer comorbidities (Table 1). The yearly number of morbidly obese and BRS patients who underwent CRC resections concurrently increased across all age groups (Figures 1 and 2). When stratified by age, the steepest rise in CRC was observed in BRS patients &lt;50 years of age (AAPC +18.7%, P &lt; 0.001). Conversely, non-CRC OGCs did not go up after BRS, while number of morbidly obese patients undergoing non-CRC OGCs increased in patients ≥50 years of age (AAPC +18.1%, P = 0.004). Finally, in a supplementary analysis, the number of non-BRS/non-obese patients with CRC resections, decreased in 2006-2013 [AAPC -3.3 (P = 0.002) and -3.4 (P &lt; 0.001) for patients &lt; and ≥50 respectively]. CONCLUSION: Our results identify a recent paradoxical increase in CRC resections after bariatric surgery, most pronounced for early-age onset CRC. Other obesity-related gastrointestinal cancers did not increase after bariatric surgery, suggesting a low probability of referral bias leading to our findings. Further research is warranted to elaborate on these trends and provide biological context.

Long-term Risk of Colorectal Cancer After Removal of Conventional Adenomas and Serrated Polyps

Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance. We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses' Health Study 1 (1990-2012), Nurses' Health Study 2 (1989-2013), or the Health Professionals Follow-up Study (1990-2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (<10 mm). We used a Cox proportional hazards regression model to calculate the hazard ratios (HRs) of CRC incidence, after adjusting for various potential risk factors. After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval [CI] 2.89-5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37-8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68-2.16, P= .52) or small serrated polyps (HR 1.25; 95% CI 0.76-2.08; P= .38). These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.

687 – Long-Term Risk of Colorectal Cancer After Removal of Conventional Adenoma and Serrated Polyp: A Prospective Study Within Three US Cohorts

687 – Long-Term Risk of Colorectal Cancer After Removal of Conventional Adenoma and Serrated Polyp: A Prospective Study Within Three US Cohorts

Long-term Risk of Colorectal Cancer and Related Deaths After a Colonoscopy With Normal Findings

Guidelines recommend a 10-year rescreening interval after a colonoscopy with normal findings (negative colonoscopy results), but evidence supporting this recommendation is limited. To examine the long-term risks of colorectal cancer and colorectal cancer deaths after a negative colonoscopy result, in comparison with individuals unscreened, in a large, community-based setting. A retrospective cohort study was conducted in an integrated health care delivery organization serving more than 4 million members across Northern California. A total of 1 251 318 average-risk screening-eligible patients (age 50-75 years) between January 1, 1998, and December 31, 2015, were included. The study was concluded on December 31, 2016. Screening was examined as a time-varying exposure; all participants contributed person-time unscreened until they were either screened or censored. If the screening received was a negative colonoscopy result, the participants contributed person-time in the negative colonoscopy results group until they were censored. Using Cox proportional hazards regression models, the hazard ratios (HRs) for colorectal cancer and related deaths were calculated according to time since negative colonoscopy result (or since cohort entry for those unscreened). Hazard ratios were adjusted for age, sex, race/ethnicity, Charlson comorbidity score, and body mass index. Of the 1 251 318 patients, 613 692 were men (49.0%); mean age was 55.6 (7.0) years. Compared with the unscreened participants, those with a negative colonoscopy result had a reduced risk of colorectal cancer and related deaths throughout the more than 12-year follow-up period, and although reductions in risk were attenuated with increasing years of follow-up, there was a 46% lower risk of colorectal cancer (hazard ratio, 0.54; 95% CI, 0.31-0.94) and 88% lower risk of related deaths (hazard ratio, 0.12; 95% CI, 0.02-0.82) at the current guideline-recommended 10-year rescreening interval. A negative colonoscopy result in average-risk patients was associated with a lower risk of colorectal cancer and related deaths for more than 12 years after examination, compared with unscreened patients. Our study findings may be able to inform guidelines for rescreening after a negative colonoscopy result and future studies to evaluate the costs and benefits of earlier vs later rescreening intervals.

Effects of aspirin on risks of vascular events and cancer according to bodyweight and dose: analysis of individual patient data from randomised trials

SummaryBackgroundA one-dose-fits-all approach to use of aspirin has yielded only modest benefits in long-term prevention of cardiovascular events, possibly due to underdosing in patients of large body size and excess dosing in patients of small body size, which might also affect other outcomes.MethodsUsing individual patient data, we analysed the modifying effects of bodyweight (10 kg bands) and height (10 cm bands) on the effects of low doses (≤100 mg) and higher doses (300–325 mg or ≥500 mg) of aspirin in randomised trials of aspirin in primary prevention of cardiovascular events. We stratified the findings by age, sex, and vascular risk factors, and validated them in trials of aspirin in secondary prevention of stroke. Additionally, we assessed whether any weight or height dependence was evident for the effect of aspirin on 20-year risk of colorectal cancer or any in-trial cancer.ResultsAmong ten eligible trials of aspirin in primary prevention (including 117 279 participants), bodyweight varied four-fold and trial median weight ranged from 60·0 kg to 81·2 kg (p<0·0001). The ability of 75–100 mg aspirin to reduce cardiovascular events decreased with increasing weight (pinteraction=0·0072), with benefit seen in people weighing 50–69 kg (hazard ratio [HR] 0·75 [95% CI 0·65–0·85]) but not in those weighing 70 kg or more (0·95 [0·86–1·04]; 1·09 [0·93–1·29] for vascular death). Furthermore, the case fatality of a first cardiovascular event was increased by low-dose aspirin in people weighing 70 kg or more (odds ratio 1·33 [95% CI 1·08–1·64], p=0·0082). Higher doses of aspirin (≥325 mg) had the opposite interaction with bodyweight (difference pinteraction=0·0013), reducing cardiovascular events only at higher weight (pinteraction=0·017). Findings were similar in men and women, in people with diabetes, in trials of aspirin in secondary prevention, and in relation to height (pinteraction=0·0025 for cardiovascular events). Aspirin-mediated reductions in long-term risk of colorectal cancer were also weight dependent (pinteraction=0·038). Stratification by body size also revealed harms due to excess dosing: risk of sudden death was increased by aspirin in people at low weight for dose (pinteraction=0·0018) and risk of all-cause death was increased in people weighing less than 50 kg who were receiving 75–100 mg aspirin (HR 1·52 [95% CI 1·04–2·21], p=0·031). In participants aged 70 years or older, the 3-year risk of cancer was also increased by aspirin (1·20 [1·03–1·47], p=0·02), particularly in those weighing less than 70 kg (1·31 [1·07–1·61], p=0·009) and consequently in women (1·44 [1·11–1·87], p=0·0069).InterpretationLow doses of aspirin (75–100 mg) were only effective in preventing vascular events in patients weighing less than 70 kg, and had no benefit in the 80% of men and nearly 50% of all women weighing 70 kg or more. By contrast, higher doses of aspirin were only effective in patients weighing 70 kg or more. Given that aspirin's effects on other outcomes, including cancer, also showed interactions with body size, a one-dose-fits-all approach to aspirin is unlikely to be optimal, and a more tailored strategy is required.FundingWellcome Trust and National Institute for Health Research Oxford Biomedical Research Centre.

Long-term risk of colorectal cancer after negative colonoscopy in a Danish gFOBT screening cohort.

Faecal occult blood test (FOBT) screening for colorectal cancer (CRC) is implemented in several countries. Approximately half of all screen positive persons have negative colonoscopy, but consensus is lacking on how these persons should be followed up. Health authorities in Denmark and The Netherlands recommend suspending screening for 8-10 years, while patients in UK are invited to screening after 2 years. In this cohort-study, we followed 166,277 individuals invited to FOBT-screening in 2005-2006 and a reference group comprising the remaining 1,240,348 Danes of the same age. We linked Danish population and health service registers to obtain information about colonoscopy outcome and incident CRC. We estimated CRC risk by colonoscopy outcome (adenoma, other colorectal pathology or negative colonoscopy) for the reference group, the screening group, and subgroups. Persons with positive screening FOBT followed by negative colonoscopy had the same long-term CRC risk as persons with adenoma detected due to a positive screening FOBT (aHR 1.33, 95% CI: 0.65-2.71). We found no difference in the long-term CRC risk between persons with negative colonoscopy after a positive FOBT screening test and the unscreened reference population (aHR 1.05, 95% CI: 0.62-1.78). Since FOBT screen positive persons in our study remained at average risk of CRC despite of a negative index colonoscopy, we question the safety of suspending FOBT screening for this group. It needs to be monitored whether recent efforts to improve colonoscopy quality have been successful in ensuring low CRC risk after negative colonoscopy also in FOBT positive persons.

Long-term risk of colorectal cancer by gender after positive colonoscopy: population-based cohort study

Background: Evidence for surveillance intervals of colonoscopy are primarily based on adenoma recurrence rate rather than on colorectal cancer (C.R.C.) incidence. Little is known about long-term risk of C.R.C. after positive colonoscopy. In view of men have significantly higher C.R.C. risk than women, we aimed to estimate the gender-specific C.R.C. incidence after positive colonoscopy (adenoma or malignant lesion) at follow-up colonoscopy.Methods: A retrospective cohort study was conducted using data from a database of colonoscopy screening and surveillance. Patients having had a colonoscopy (January 2010–March 2014) were selected as study subjects and the history of prior colonoscopies was reviewed. Multivariable Weibull regression models were used to estimate the incidence of C.R.C. at follow-up colonoscopy for subjects who were assigned a stratified risk level. The benchmark risk was defined according to a national survey.Results: The interval incidence of C.R.C. at a 10 year follow-up was 164 (95% C.I. 63–343) and 79 (95% C.I. 26–188) per 100,000 person-years for low-risk men and women respectively, which tallied with our benchmark risk. Men exceeded the benchmark risk in 3–5 years if they had an incomplete polyp removal, ≥3 adenomas during their last colonoscopy or a personal C.R.C. history, and in 7–8 years if they only had familial C.R.C. history. Women had a lower risk of C.R.C., and reached a same risk level 3–5 years later than men. Coexisting above risk factors resulted in a sharp increase in the incidence of C.R.C. at follow-up exceeding the benchmark much earlier.Conclusion: Surveillance intervals for men based on incidence of C.R.C. are in line with that recommended by the current guidelines for colonoscopy. However, an extension of 3–5 years may be appropriate for women. To target personalized medicine, a risk predictive model could be used to identify an appropriate surveillance interval for each individual in the future.

Increased Risk of Colorectal Cancer After Obesity Surgery

Author(s): Derogar, Maryam; Hull, Mark A; Kant, Prashant; Ostlund, Magdalena; Lu, Yunxia; Lagergren, Jesper | Abstract: ObjectiveThe purpose was to determine whether obesity surgery is associated with a long-term increased risk of colorectal cancer.BackgroundLong-term cancer risk after obesity surgery is not well characterized. Preliminary epidemiological observations and human tissue biomarker studies recently suggested an increased risk of colorectal cancer after obesity surgery.MethodsA nationwide retrospective register-based cohort study in Sweden was conducted in 1980-2009. The long-term risk of colorectal cancer in patients who underwent obesity surgery, and in an obese no surgery cohort, was compared with that of the age-, sex- and calendar year-matched general background population between 1980 and 2009. Obese individuals were stratified into an obesity surgery cohort and an obese no surgery cohort. The standardized incidence ratio (SIR), with 95% confidence interval (CI), was calculated.ResultsOf 77,111 obese patients, 15,095 constituted the obesity surgery cohort and 62,016 constituted the obese no surgery cohort. In the obesity surgery cohort, we observed 70 patients with colorectal cancer, rendering an overall SIR of 1.60 (95% CI 1.25-2.02). The SIR for colorectal cancer increased with length of time after surgery, with a SIR of 2.00 (95% CI 1.48-2.64) after 10 years or more. In contrast, the overall SIR in the obese no surgery cohort (containing 373 colorectal cancers) was 1.26 (95% CI 1.14-1.40) and remained stable with increasing follow-up time.ConclusionsObesity surgery seems to be associated with an increased risk of colorectal cancer over time. These findings would prompt evaluation of colonoscopy surveillance for the increasingly large population who undergo obesity surgery.

Long-term risk of colorectal cancer in individuals with serrated polyps

ObjectiveAlthough serrated polyps may be precursors of colorectal cancer (CRC), prospective data on the long-term CRC risk in individuals with serrated polyps are lacking.DesignIn a population-based randomised trial, 12 955...

Abstract 2201: Long-term risk of colorectal cancer in patients with sessile serrated adenomas, traditional serrated adenomas, and hyperplastic polyps

Abstract Evidence for the recently recognized serrated pathway to colorectal cancer (CRCa) is based largely on the similarity of genetic changes in CpG island methylator phenotype positive (CIMP+) cancers and serrated lesions such as the sessile serrated adenoma (SSA). There is limited evidence regarding the future cancer risks in patients diagnosed with these lesions. Methods: We used Danish medical databases to select subjects for a population-based case-control study of CRCa within the population of 272,342 individuals who underwent colonoscopy during 1977 - 2009. 2,045 CRCa cases were diagnosed during 1977-2006. We used risk set sampling to select 8,105 controls matched by gender and year of birth to the cases. After accessing records of colorectal polyps identified in the subjects, we requested histopathological blocks for the first lesions diagnosed as hyperplastic polyps (HPs) at or after the first colonoscopy during the study period, and obtained them for 895 (97%) of the affected subjects. Four expert pathologists used current criteria to review these lesions and reclassify them as SSAs, traditional serrated adenomas (TSAs) or hyperplastic polyps (HPs). Lesions initially diagnosed as conventional adenomas (CADs) were not reviewed, nor were later polyps. We used conditional logistic regression to compute odds ratios (ORs) and 95% confidence limits (CIs) for CRCa associated with polyp types at the first examination recorded with HPs, using patients with no polyp history during the study period as the referent group and adjusting for age and year at first colonoscopy. Results: After review, 48 (2.3%) cases and 81 (1.0%) controls had SSAs but no CADs or TSAs (OR for CRCa = 3.34, 95% CI: 2.31-4.83). TSAs conferred a similarly high CRCa risk (OR = 3.35, 95%CI: 1.39-8.07), but HPs did not (OR = 1.30, 95% CI: 0.96-1.77). The OR for CADs without SSA or TSA was 2.49 (95% CI: 2.23-2.79); subjects with both SSAs and CADs had an OR intermediate between those for CADs alone and SSAs alone. Women with SSAs and no CADs had a higher OR (4.92; 95% CI: 2.96-8.18) than men (OR = 2.18, 95% CI: 1.24-3.82). Proximal SSAs were associated with a particularly high OR (12.39, 95% CI: 4.87-31.51). Consideration of reported metachronous lesions changed most of these ORs only modestly. Conclusions: We found that SSAs and TSAs are associated with a substantial increase in the risk of CRCa. These data provide further evidence for the serrated pathway to CRCa, with SSAs and TSAs as cancer precursors. Citation Format: John A. Baron, Rune Erichsen, Stephen J. Hamilton-Dutoit, Dale C. Snover, Emina E. Torlakovic, Trine Frøslev, Lars Pedersen, Mogens Vyberg, Stanley R. Hamilton, Henrik T. Sørensen. Long-term risk of colorectal cancer in patients with sessile serrated adenomas, traditional serrated adenomas, and hyperplastic polyps. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2201. doi:10.1158/1538-7445.AM2014-2201

Rural–urban differences in the long-term risk of colorectal cancer after adenoma removal: A population-based study

We investigated the impact of municipality of residence on colonoscopic surveillance and colorectal cancer risk after adenoma resection in a French well-defined administrative area. This registry-based study included all patients residing in Côte d'Or (n=5769) first diagnosed with colorectal adenomas between January 1, 1990, and December 31, 1999. Information about colonoscopic surveillance and colorectal cancer incidence was collected until December 31, 2003. A rural place of residence reduced the probability of colonoscopic surveillance in men [HR=0.89 (95%CI: 0.79-0.99), p=0.041] and in patients without family history of colorectal cancer [HR=0.91(0.82-0.99), p=0.044]. After a median follow-up of 7.7 years, 87 patients developed invasive colorectal cancer. After advanced adenoma removal, the standardized incidence ratio for colorectal cancer was 3.03 (95%CI: 1.92-4.54) for rural patients and 1.87 (95%CI: 1.26-2.66) for urban patients compared with the general population. The risk of colorectal cancer was higher in rural patients than in urban ones only after removal of the initial advanced adenoma [HR=1.73 (95%CI: 1.01-3.00, p=0.048)]. Further adjustment for surveillance colonoscopy, physician location, and other confounders had little impact on these results. The increased risk of subsequent colorectal cancer after advanced adenoma removal in French rural patients was not explained by a lower rate of colonoscopic surveillance. The role of socio-economic and environmental factors requires further exploration.

Increased Risk of Colorectal Cancer After Obesity Surgery

The purpose was to determine whether obesity surgery is associated with a long-term increased risk of colorectal cancer. Long-term cancer risk after obesity surgery is not well characterized. Preliminary epidemiological observations and human tissue biomarker studies recently suggested an increased risk of colorectal cancer after obesity surgery. A nationwide retrospective register-based cohort study in Sweden was conducted in 1980-2009. The long-term risk of colorectal cancer in patients who underwent obesity surgery, and in an obese no surgery cohort, was compared with that of the age-, sex- and calendar year-matched general background population between 1980 and 2009. Obese individuals were stratified into an obesity surgery cohort and an obese no surgery cohort. The standardized incidence ratio (SIR), with 95% confidence interval (CI), was calculated. Of 77,111 obese patients, 15,095 constituted the obesity surgery cohort and 62,016 constituted the obese no surgery cohort. In the obesity surgery cohort, we observed 70 patients with colorectal cancer, rendering an overall SIR of 1.60 (95% CI 1.25-2.02). The SIR for colorectal cancer increased with length of time after surgery, with a SIR of 2.00 (95% CI 1.48-2.64) after 10 years or more. In contrast, the overall SIR in the obese no surgery cohort (containing 373 colorectal cancers) was 1.26 (95% CI 1.14-1.40) and remained stable with increasing follow-up time. Obesity surgery seems to be associated with an increased risk of colorectal cancer over time. These findings would prompt evaluation of colonoscopy surveillance for the increasingly large population who undergo obesity surgery.

Long-term risk of colorectal cancer after negative colonoscopy

Long-term risk of colorectal cancer after negative colonoscopy

Long-term risk of colorectal cancer after negative colonoscopy

Long-term risk of colorectal cancer after negative colonoscopy