Colonoscopy plays an important role in detecting colorectal neoplasms in patients with gastric neoplasms

BACKGROUND Gastric cancer(GC)and colorectal cancer(CRC)are the fifth and third most common cancer worldwide,respectively.Nowadays,GC is reported to have a potential predictive value for CRC,especially for advanced CRC.AIM To evaluate the necessity of colonoscopy for gastric neoplasm(GN)patients.METHODS Four databases,including PubMed,EMBASE,the Cochrane Library,and Ovid,were used to perform the search strategy on May 2,2023.The prevalence of colorectal neoplasms(CRN)and baseline characteristics were compared between the neoplasm group and the control group.Continuous variables are expressed as the mean difference and standard deviation.Relationships of categorical variables in the two groups are expressed as odds ratios(OR)and 95%confidence intervals(95%CIs).Subgroup analysis according to different kinds of GNs was conducted for more in-depth analysis.The results of this study are represented by forest plots.Publication bias was evaluated by a funnel plot.All data analyses were performed by STATA SE 16.0 software.RESULTS A total of 3018 patients with GNs and 3905 healthy controls(age and sex matched)were enrolled for analysis.After comparing the prevalence of CRNs between the two groups,CRNs were detected significantly more frequently in GN patients than in controls(OR=1.69,95%CI=1.28 to 2.23,I^(2)=85.12%,P=0.00),especially in patients with GC(OR=1.80,95%CI=1.49 to 2.18,I^(2)=25.55%,P<0.1).Moreover,other risk factors including age(OR=1.08,95%CI=1.00 to 1.17,I^(2)=90.13%,P=0.00)and male sex(OR=2.31,95%CI=1.26 to 4.22,I^(2)=87.35%,P=0.00),were related to the prevalence of CRNs.For patients in the GN group,body mass index(BMI,OR=0.88,95%CI=0.80 to 0.98,I^(2)=0.00%,P=0.92)and smoking(OR=1.03,95%CI=1.01 to 1.05,I^(2)=0.00%,P=0.57)were protective and risk factors for CRNs,respectively.CONCLUSION Patients are recommended to undergo colonoscopy when diagnosed with GNs,especially GC patients with a low BMI and a history of smoking.

Different lymph node staging systems for predicting the prognosis of colorectal neuroendocrine neoplasms

BACKGROUND Colorectal neuroendocrine neoplasms(NENs)are a rare malignancy that primarily arises from the diffuse distribution of neuroendocrine cells in the colon and rectum.Previous studies have pointed out that the status of lymph node may be used to predict the prognosis.AIM To investigate the predictive values of lymph node ratio(LNR),positive lymph node(PLN),and log odds of PLNs(LODDS)staging systems on the prognosis of colorectal NENs treated surgically,and compare their predictive values.METHODS This cohort study included 895 patients with colorectal NENs treated surgically from the Surveillance,Epidemiology,and End Results database.The endpoint was mortality of patients with colorectal NENs treated surgically.X-tile software was utilized to identify most suitable thresholds for categorizing the LNR,PLN,and LODDS.Participants were selected in a random manner to form training and testing sets.The prognosis of surgically treating colorectal NENs was examined using multivariate cox analysis to assess the associations of LNR,PLN,and LODDS with the prognosis of colorectal NENs.C-index was used for assessing the predictive effectiveness.We conducted a subgroup analysis to explore the different lymph node staging systems’predictive values.RESULTS After adjusting all confounding factors,PLN,LNR and LODDS staging systems were linked with mortality in patients with colorectal NENs treated surgically(P<0.05).We found that LODDS staging had a higher prognostic value for patients with colorectal NENs treated surgically than PLN and LNR staging systems.Similar results were obtained in the different G staging subgroup analyses.Furthermore,the area under the receiver operating characteristic curve values for LODDS staging system remained consistently higher than those of PLN or LNR,even at the 1-,2-,3-,4-,5-and 6-year follow-up periods.CONCLUSION LNR,PLN,and LODDS were found to significantly predict the prognosis of patients with colorectal NENs treated surgically.

Synchronous manifestation of colorectal cancer and intraductal papillary mucinous neoplasms

High rates of extrapancreatic malignancies,in particular colorectal cancer(CRC),have been detected in patients with intraductal papillary mucinous neoplasm(IPMN).So far,there is no distinct explanation in the literature for the development of secondary or synchronous malignancies in patients with IPMN.In the past few years,some data related to common genetic alterations in IPMN and other affiliated cancers have been published.This review elucidated the association between IPMN and CRC,shedding light on the most relevant genetic alterations that may explain the possible relationship between these entities.In keeping with our findings,we suggested that once the diagnosis of IPMN is made,special consideration of CRC should be undertaken.Presently,there are no specific guidelines regarding colorectal screening programs for patients with IPMN.We recommend that patients with IPMNs are at high-risk for CRC,and a more rigorous colorectal surveillance program should be implemented.

Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?

BACKGROUND Colorectal cancer(CRC)is a global health concern,with advanced-stage diagnoses contributing to poor prognoses.The efficacy of CRC screening has been well-established;nevertheless,a significant proportion of patients remain unscreened,with>70%of cases diagnosed outside screening.Although identifying specific subgroups for whom CRC screening should be particularly recommended is crucial owing to limited resources,the association between the diagnostic routes and identification of these subgroups has been less appreciated.In the Japanese cancer registry,the diagnostic routes for groups discovered outside of screening are primarily categorized into those with comorbidities found during hospital visits and those with CRC-related symptoms.AIM To clarify the stage at CRC diagnosis based on diagnostic routes.METHODS We conducted a retrospective observational study using a cancer registry of patients with CRC between January 2016 and December 2019 at two hospitals.The diagnostic routes were primarily classified into three groups:Cancer screening,follow-up,and symptomatic.The early-stage was defined as Stages 0 or I.Multivariate and univariate logistic regressions were exploited to determine the odds of early-stage diagnosis in the symptomatic and cancer screening groups,referencing the follow-up group.The adjusted covariates were age,sex,and tumor location.RESULTS Of the 2083 patients,715(34.4%),1064(51.1%),and 304(14.6%)belonged to the follow-up,symptomatic,and cancer screening groups,respectively.Among the 2083 patients,CRCs diagnosed at an early stage were 57.3%(410 of 715),23.9%(254 of 1064),and 59.5%(181 of 304)in the follow-up,symptomatic,and cancer screening groups,respectively.The symptomatic group exhibited a lower likelihood of early-stage diagnosis than the follow-up group[P<0.001,adjusted odds ratio(aOR),0.23;95%confidence interval(95%CI):0.19-0.29].The likelihood of diagnosis at an early stage was similar between the follow-up and cancer screening groups(P=0.493,aOR for early-stage diagnosis in the cancer screening group vs follow-up group=1.11;95%CI=0.82-1.49).CONCLUSION CRCs detected during hospital visits for comorbidities were diagnosed earlier,similar to cancer screening.CRC screening should be recommended,particularly for patients without periodical hospital visits for comorbidities.

Non-participation of asymptomatic candidates in screening protocols reduces early diagnosis and worsens prognosis of colorectal cancer

The Agatsuma et al’s study shows that despite the evidence of the benefits of an early colorectal cancer(CRC)diagnosis,through screening in asymptomatic subjects,up to 50%of candidates reject this option and many of those affected are diagnosed later,in advanced stages.The efficacy of screening programs has been well-established for several years,which reduces the risk of CRC morbidity and mortality,without taking into account the test used for screening,or other tools.Nevertheless,a significant proportion of patients remain unscreened,so understanding the factors involved,as well as the barriers of the population to adherence is the first step to possibly modify the participation rate.These barriers could include a full range of social and political aspects,especially the type of financial provision of each health service.In Japan,health services are universal,and this advantageous situation makes it easier for citizens to access to these services,contributing to the detection of various diseases,including CRC.Interestingly,the symptomatic CRC group had a lower early-stage diagnosis rate than the patients detected during follow-up for other comorbidities,and symptomatic and cancer screening groups showed similar early-stage diagnosis.

Anti-EGFR antibody monotherapy for colorectal cancer with severe hyperbilirubinemia: A case report

BACKGROUND Hyperbilirubinemia with hepatic metastases is a common complication and a poor prognostic factor for colorectal cancer(CRC).Effective drainage is often im-possible before initiating systemic chemotherapy,owing to the liver’s diffuse metastatic involvement.Moreover,an appropriate chemotherapeutic approach for the treatment of hyperbilirubinemia is currently unavailable.CASE SUMMARY The patient,a man in his 50s,presented with progressive fatigue and severe jaundice.Computed tomography revealed multiple hepatic masses with thick-ened walls in the sigmoid colon,which was pathologically confirmed as a well-differentiated adenocarcinoma.No RAS or BRAF mutations were detected.The Eastern Cooperative Oncology Group(ECOG)performance status(PS)score was 2.Biliary drainage was impossible due to the absence of a dilated bile duct,and panitumumab monotherapy was promptly initiated.Subsequently,the bilirubin level decreased and then normalized,and the patient’s PS improved to zero ECOG score after four cycles of therapy without significant adverse events.CONCLUSION Anti-EGFR antibody monotherapy is a safe and effective treatment for RAS wild-type CRC and hepatic metastases with severe hyperbilirubinemia.

Optimization of colorectal cancer screening strategies: New insights

In this editorial,we discuss the article by Agatsuma et al.We concentrate specifically on the current routinely used screening tests recommended by society guidelines and delve into the significance of early diagnosis of colorectal cancer(CRC)and its substantial impact on both incidence and mortality rates.Screening is highly recommended,and an early diagnosis stands out as the most crucial predictor of survival for CRC patients.Therefore,it is essential to identify and address the barriers hindering adherence to screening measures,as these barriers can vary among different populations.Furthermore,we focus on screening strategy optimization by selecting high-risk groups.Patients with comorbidities who regularly visit hospitals have been diagnosed at an early stage,showing no significant difference compared to patients undergoing regular screening.This finding highlights the importance of extending screening measures to include patients with comorbidities who do not routinely visit the hospital.

Value of glucose transport protein 1 expression in detecting lymph node metastasis in patients with colorectal cancer

BACKGROUND There are limited data on the use of glucose transport protein 1(GLUT-1)expre-ssion as a biomarker for predicting lymph node metastasis in patients with colorectal cancer.GLUT-1 and GLUT-3,hexokinase(HK)-II,and hypoxia-induced factor(HIF)-1 expressions may be useful biomarkers for detecting primary tumors and lymph node metastasis when combined with fluorodeoxyglucose(FDG)uptake on positron emission tomography/computed tomography(PET/CT).AIM To evaluate GLUT-1,GLUT-3,HK-II,and HIF-1 expressions as biomarkers for detecting primary tumors and lymph node metastasis with 18F-FDG-PET/CT.METHODS This retrospective study included 169 patients with colorectal cancer who underwent colectomy and preoperative 18F-FDG-PET/CT at Chungbuk National University Hospital between January 2009 and May 2012.Two tissue cores from the central and peripheral areas of the tumors were obtained and were examined by a dedicated pathologist,and the expressions of GLUT-1,GLUT-3,HK-II,and HIF-1 were determined using immunohisto-chemical staining.We analyzed the correlations among their expressions,various clinicopathological factors,and the maximum standardized uptake value(SUVmax)of PET/CT.RESULTS GLUT-1 was found at the center or periphery of the tumors in 109(64.5%)of the 169 patients.GLUT-1 positivity was significantly correlated with the SUVmax of the primary tumor and lymph nodes,regardless of the biopsy site(tumor center,P<0.001 and P=0.012;tumor periphery,P=0.030 and P=0.010,respectively).GLUT-1 positivity and negativity were associated with higher and lower sensitivities of PET/CT,respectively,for the detection of lymph node metastasis,regardless of the biopsy site.GLUT3,HK-II,and HIF-1 expressions were not significantly correlated with the SUVmax of the primary tumor and lymph nodes.CONCLUSION GLUT-1 expression was significantly correlated with the SUVmax of 18F-FDG-PET/CT for primary tumors and lymph nodes.Clinicians should consider GLUT-1 expression in preoperative endoscopic biopsy in interpreting PET/CT findings.

Research progresses of dual-layer spectral detector CT for preoperative evaluation on colorectal cancer

Dual-layer spectral detector CT is a new spectrum CT imaging technology based on detector being able to obtain both images similar to true plain and spectral images in one time scanning.The reconstructed multi-parameter spectral images can not only improve image quality,enhance tissue contrast,increase the visualization and detection ability of occult lesions,but also provide qualitative and quantitative analysis of the lesions,so as to provide more imaging information and multi-dimensional diagnostic basis.The research progresses of dual-layer spectral detector CT for preoperative evaluation on colorectal cancer were reviewed in this article.

Symptom Experience and Quality of Life in Colorectal Cancer Patients Undergoing Chemotherapy-A Secondary Publication

Objective:To evaluate symptom experience and quality of life(QoL)and to identify the predictors of QoL among colorectal cancer patients undergoing chemotherapy.Methods:A cross-sectional study was conducted on 107 colorectal cancer patients at a university-affiliated hospital between June 1 and July 30,2021.Functional Assessment of Cancer Therapy-Colorectal(FACT-C)and Memorial Symptom Assessment Scale-Short Form(MSAS-SF)were used to assess symptom experience and QoL of these patients.Data were analyzed using Pearson’s correlation,t-test,ANOVA,and hierarchical multiple regression.Results:The mean QoL score for colorectal cancer patients was 88.78±20.08.The most frequently experienced physical and psychological symptoms were numbness/tingling and worrying.Physical and psychological symptoms have a significant negative association with QoL.Perceived economic status was significantly associated with QoL in patients’general characteristics.The regression analyses showed that high psychological symptoms(β=-0.63,P<0.001),middle perceived economic status(β=-0.22,P=0.009),and low perceived economic status(β=-0.36,P<0.001)were statistically significant in predicting patients’low QoL.Conclusion:Symptom experience and QoL are essential variables that should be acknowledged when delivering health care to colorectal cancer patients.More attention to the reduction and comprehensive symptom management of psychological distress could improve QoL among colorectal cancer patients.

Risk factors for bleeding after endoscopic submucosal dissection of colorectal neoplasms

AIM: To investigate the risk factors for delayed bleeding following endoscopic submucosal dissection (ESD) treatment for colorectal neoplasms.

Clinical significance of type V_I pit pattern subclassification in determining the depth of invasion of colorectal neoplasms

AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospectively analyzed 272 colorectal neoplasms (117 dysplasias and 155 submucosal invasive carcinomas; 228 patients) with a type V pit pattern [type VI, n = 202; type VN, n = 70 (Kudo and Tsuruta classification system)]. We divided lesions with a type VI pit pattern into two subclasses, mildly irregular lesions and severely irregular lesions, according to the prominent and detailed magnifying colonoscopy findings. We examined the relation between these two subclasses and histology/invasion depth.RESULTS: One hundred and four lesions (51.5%) were judged to be mildly irregular, and 98 lesions (48.5%) were judged to be severely irregular. Ninety-seven (93.3%) mildly irregular lesions showed dysplasias or submucosal invasion of less than 1000 μm (SM < 1000 μm). Fifty-five (56.1%) severely irregular lesions showed submucosal invasion equal to or deeper than 1000 μm (SM ≥ 1000 μm). Mild irregularity was found significantly more often in dysplasias or lesions with SM < 1000 μm than in lesions with SM ≥ 1000 μm (P < 0.01).CONCLUSION: Subclassification of the type VI pit pattern is useful for identifying dysplasias or lesions with SM < 1000 μm.

Endoscopic submucosal dissection for colorectal neoplasms

Although endoscopic submucosal dissection(ESD) gains acceptance as one of the standard treatments for esophageal and stomach neoplasms in Japan,it is still in the developing stage for colorectal neoplasms.In terms of indications,little likelihood of nodal metastasis and technical resectability are principally considered.Some of intramucosal neoplasms,carcinomas with minute submucosal invasion,and carcinoid tumors,which are technically unresectable by conventional endoscopic treatments,may become good candidates for ESD,considering substantial risks and obtained benefits.ESD as a staging measure to obtain histological information of the invasion depth and lymphovascular infiltration is acceptable because preoperative prediction is difficult in some cases.In terms of techniques,advantages of ESD in comparison with other endoscopic treatments are to be controllable in size and shape,and to be resectable even in large and fibrotic neoplasms.The disadvantages may be longer procedure time,heavier bleeding,and higher possibility of perforation.However,owing to refinement of the techniques,invention of devices,and the learning curve,acceptable technical safety has been achieved.Colorectal ESD is very promising and become one of the standard treatments for colorectal neoplasms in the near future.

Association between white opaque substance under magnifying colonoscopy and lipid droplets in colorectal epithelial neoplasms

AIM To examine the association between white opaque substance(WOS) and histologically verified lipiddroplets in colorectal epithelial neoplasms.METHODS We reviewed colonoscopy records at our institution from 2014 to 2016 and identified cases of endoscopically or surgically resected colorectal epithelial neoplasms observed by magnifying narrow-band imaging(M-NBI) colonoscopy. Immunohistochemistry was used to stain tumors with a monoclonal antibody specific to adipophilin as a marker of lipids. The expression and distribution of adipophilin were compared between WOS-positive and WOS-negative lesions and among tumors classified by histologic type and depth of invasion.RESULTS Under M-NBI colonoscopy, 81 lesions were positive for WOS and 48 lesions were negative for WOS. The rate of adipophilin expression was significantly higher in WOS-positive lesions(95.1%) than in WOS-negative lesions(68.7%)(P = 0.0001). The incidence of deep adipophilin expression was higher in WOS-positive lesions(24.7%) than in WOS-negative lesions(4.2%)(P = 0.001). The incidence of deep expression was predominant among cancers with massive submucosal invasion(62.5%) compared to adenoma(7.2%) and high-grade dysplasia or cancers with slight submucosal invasion(12.7%)(P = 0.0001).CONCLUSION The distribution of lipid droplets may be closely associated with the visibility of WOS under M-NBI colonoscopy, and with histologic grade and depth of tumor invasion.

CYP1A1,CYP2E1 and EPHX1 polymorphisms in sporadic colorectal neoplasms

AIM To investigate the contribution of polymorphisms in the CYP1A1, CYP2E1 and EPHX1 genes on sporadic colorectal cancer(SCRC) risk. METHODS Six hundred forty-one individuals(227 patients with SCRC and 400 controls) were enrolled in the study. The variables analyzed were age, gender, tobacco and alcohol consumption, and clinical and histopathological tumor parameters. The CYP1A1 *2A, CYP1A1 *2C CYP2E1 *5B and CYP2E1 *6 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The EPHX1 Tyr113 His, EPHX1 His139 Arg and CYP1A1 *2C polymorphisms were detected by real-time PCR. Chisquared test and binary logistic regression were used in the statistical analysis. Haplotype analysis was conducted using the Haploview program, version 2.05.RESULTS Age over 6 2 years was a risk factor for SCRC development(OR = 7.54, 95%CI: 4.94-11.50, P < 0.01). Male individuals were less susceptible to SCRC(OR = 0.55, 95%CI: 0.35-0.85, P < 0.01). The CYP2E1*5B polymorphism was associated with SCRC in the codominant(heterozygous genotype: OR = 2.66, 95%CI: 1.64-4.32, P < 0.01), dominant(OR = 2.82, 95%CI: 1.74-4.55, P < 0.01), overdominant(OR = 2.58, 95%CI: 1.59-4.19, P < 0.01), and log-additive models(OR = 2.84, 95%CI: 1.78-4.52, P < 0.01). The CYP2E1*6 polymorphism was associated with an increased SCRC risk in codominant(heterozygous genotype: OR = 2.81, 95%CI: 1.84-4.28, P < 0.01; homozygous polymorphic : OR = 7. 3 2, 9 5 % C I : 1.85-28.96, P < 0.01), dominant(OR = 2.97, 95%CI: 1.97-4.50, P < 0.01), recessive(OR = 5.26, 95%CI: 1.35-20.50, P = 0.016), overdominant(OR = 2.64, 95%CI: 1.74-4.01, P < 0.01), and log-additive models(OR = 2.78, 95%CI: 1.91-4.06, P < 0.01). The haplotype formed by the minor alleles of the CYP2E1*5B(C) and CYP2E1*6(A) polymorphisms was associated with SCRC(P = 0.002). However, the CYP1A1 *2A, CYP1A1 *2C, EPHX1 Tyr113 His and EPHX1 His139 Arg polymorphisms were not associated with SCRC.CONCLUSION In conclusion, the results demonstrated that CYP2E1*5B and CYP2E1*6 minor alleles play a role in the development of SCRC.

Incidence and localization of lymphoid follicles in early colorectal neoplasms

AIM： TO investigate the incidence and Iocalizations of lymphoid follicles （LFs） in early colorectal neoplasms in human beings. METHODS： From July 1992 to September 1999, a total of 1 324 early colorectal neoplasms were removed endoscopically or surgically at our hospital; 1 031 （77.9%） were available for analysis in this study. Localization of LFs was defined histologically： as submucosal LFs, if located under the muscularis mucosa; and as intramucosal LFs, if located across or over the muscularis RESULTS： Histologically, the materials included 903 intramucosal neoplasms and 128 submucosal cancers. Overall incidence of LFs was 27.2% （280/1 031）. The incidence of LFs was significantly higher in females （33.6% vs 24.9%, P = 0.0064）, the right-sided colon （32.2% vs 25.6%, P = 0.0403） and in flat or depressed type lesions （34.6% vs 25.2%, P〈O.O001） as compared to males, left-sided colon and protruding type lesions, respectively. The incidences of intramucosal neoplasms and submucosal cancers were 24.3% and 43.8%, respectively （P〈O.O001）. Localizations of LFs （intramucosal LF/submucosal LF） in depressed, flat, and protruding types were 1/24, 14/36, and 131/74, respectively. CONCLUSION： The incidence of LFs in early human colorectal neoplasms significantly differs by gender, location, macroscopic type, and histology. Moreover,localization significantly differs by macroscopic type.

Incidence of colorectal neoplasms among male pilots

AIM: To assess the prevalence of colorectal neoplasms (adenomas, advanced adenomas and colorectal cancers) among Israeli military and commercial airline pilots.

Study on Proteomics in Hepatic Metastasis of Colorectal neoplasms

Colorectal cancer is one of the most frequent cancers in the world. Hepatic metastasis is the most common site metastatic disease and dominant cause of death in colorectal cancer patients. In the large majority of cases, cell dysfunction in CRC results from multiple rather than single, gene interactions, so to be able to predict occurrence of disease and treatment outcome, more studies on comparative proteomics are needed both in sporadic and in hereditary colorectal cancer. This article is about the proteomic study on hepatic metastasis of colorectal cancer which helps to identify the specific proteins that play important roles in hepatic metastasis. The study of protein molecules with their expressions correlated to the metastatic process would help to understand the metastatic mechanisms and thus facilitate the development of strategies for the therapeutic interventions and clinical markagement of cancer.

Correlation between pre-treatment serum total blood bilirubin andunconjugated bilirubin and prognosis in patients with colorectalcancer

BACKGROUND Epidemiological studies have found that unconjugated bilirubin(UCB)levels are positively correlated with the incidence of colorectal cancer(CRC).Therefore,bilirubin may also play an important role in the prognosis of CRC.AIM To investigate the predictive value of total bilirubin(TBIL)and UCB in the prognosis of patients with CRC.METHODS A total of 142 CRC patients were selected as the research subjects in Jingxian Hospital,from October 2014 to May 2021.General and tumour-related clinical data at admission and the overall survival at 3 years after surgery were collected.The optimal cut-off values of TBIL and UCB were determined by receiver operating characteristic curve analysis.Univariate and multivariate Cox regression were used to analyse the effect of bilirubin level on the survival of CRC patients.The Kaplan–Meier method was used to assess the survival time.RESULTS The 3-year overall survival rate of CRC patients was significantly higher in the high TBIL(>13.45μmol/L)group than in the low TBIL(≤13.45μmol/L)group(76.4%vs 37.1%;P<0.05).The 3-year overall survival rate of CRC patients in the high UCB(>10.75μmol/L)group was significantly higher than that in the low UCB(≤10.75μmol/L)group(83.3%vs 34.2%;P<0.05).Multivariate Cox regression analysis showed that higher TBIL levels were an independent predictor of better prognosis in CRC patients(hazard ratio=0.360,95%confidence interval:0.159-0.812,P=0.014).CONCLUSION TBIL levels can be used as a prognostic indicator for CRC patients.

Different risk factors for advanced colorectal neoplasm in young adults

AIM: To compare the risk of developing advanced colorectal neoplasm(ACRN) according to age in Koreans.METHODS: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios(OR) for ACRN between the young-adults(YA < 50 years) and in the older-adults(OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.RESULTS: In the YA group, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 1.26, 95%CI: 1.02-1.55), current smoking(OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer(OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors(OR = 1.27, 95%CI: 1.06-1.54), obesity(OR = 1.23, 95%CI: 1.03-1.47), CEA(OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol(OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 2.12, 95%CI: 1.68-2.68), current smoking(OR = 1.38, 95%CI: 1.12-1.71), obesity(OR = 1.34, 95%CI: 1.09-1.65) and CEA(OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group.CONCLUSION: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.