Association Among Obesity, Metabolic Health, and the Risk for Colorectal Cancer in the General Population in Korea Using the National Health Insurance Service-National Sample Cohort

Association of metabolic obesity phenotypes with risk of overall and site-specific cancers: a systematic review and meta-analysis of cohort studies

BACKGROUND

Adiposity is a known risk factor for certain cancers; however, it is not clear whether the risk of cancer differs between individuals with high adiposity but different metabolic health status. The aim of this systematic literature review and meta-analysis of cohort studies was to evaluate associations between metabolic obesity phenotypes and overall and site-specific cancer risk.

METHODS

PubMed and Embase databases were used to identify relevant cohort studies up to the 6th of June 2023. Random-effects models were used to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs) for the association between metabolic obesity phenotypes and cancer risk. Certainty of evidence was assessed using the Cochrane methods and the GRADE tool. This study is registered with PROSPERO, number CRD42024549511.

RESULTS

A total of 15,556 records were screened, and 31 publications covering 15 unique cohort studies were included in this analysis. Of these studies, 22 were evaluated as being at low risk of bias and 9 at moderate risk of bias. Compared to metabolically healthy normal-weight individuals (MHNW), metabolically unhealthy overweight/obese (MUOW/OB) individuals had a higher risk of overall (SRR = 1.21, 95% CI = 1.02-1.44, n = 3 studies, high certainty) and obesity-related cancers (SRR = 1.42, 95% CI = 1.15-1.74, n = 3, very low certainty). Specifically, MUOW/OB individuals were at higher risk of cancers of the postmenopausal breast (SRR = 1.32, 95% CI = 1.17-1.48, n = 7, low certainty), colorectum (SRR = 1.24, 95% CI = 1.16-1.31, n = 6, moderate certainty), endometrium (SRR = 2.31, 95% CI = 2.08-2.57, n = 4, high certainty), thyroid (SRR = 1.42, 95% CI = 1.29-1.57, n = 4, moderate certainty), kidney (SRR = 1.71, 95% CI = 1.40-2.10, n = 3, low certainty), pancreas (SRR = 1.35, 95% CI = 1.24-1.47, n = 3, high certainty), liver (SRR = 1.81, 95% CI = 1.36-2.42, n = 2, moderate certainty), gallbladder (SRR = 1.42, 95% CI = 1.17-1.73, n = 2, high certainty), bladder (SRR = 1.36, 95% CI = 1.19-1.56, n = 2, moderate certainty), and stomach (SRR = 1.50, 95% CI = 1.12-2.01, n = 2, high certainty). In addition, we found elevated risks of most of these cancers among individuals classified as MUNW and MHOW/OB phenotypes compared to those with MHNW phenotype. Our stratified analyses according to metabolic obesity phenotypes suggested that the elevated risks of some cancers were stronger in individuals with MUOW/OB versus those with MHOW/OB or MUNW phenotypes.

CONCLUSION

These findings suggest that both higher adiposity and metabolic dysfunction were independently associated with increased risk of several cancers, with the strongest associations generally observed among those with both metabolic dysfunction and obesity.

Body Mass Index and Risk of Colorectal Cancer Incidence and Mortality in Asia

Importance

The global burden of obesity is increasing, as are colorectal cancer (CRC) incidence and mortality.

Objectives

To assess the association between body mass index (BMI) and risks of incident CRC and CRC-related death in the Asian population.

Design, Setting, and Participants

This cohort study includes data pooled from 17 prospective cohort studies included in The Asia Cohort Consortium. Cohort enrollment was conducted from January 1, 1984, to December 31, 2002. Median follow-up time was 15.2 years (IQR, 12.1-19.2 years). Data were analyzed from January 15, 2023, through January 15, 2024.

Exposure

Body mass index, calculated as weight in kilograms divided by height in meters squared.

Main Outcomes and Measures

The primary outcomes were CRC incidence and CRC-related mortality. The risk of events is reported as adjusted hazard ratios (AHRs) and 95% CIs for incident CRC and death from CRC using the Cox proportional hazards regression model.

Results

To assess the risk of incident CRC, 619 981 participants (mean [SD] age, 53.8 [10.1] years; 52.0% female; 11 900 diagnosed incident CRC cases) were included in the study, and to assess CRC-related mortality, 650 195 participants (mean [SD] age, 53.5 [10.2] years; 51.9% female; 4550 identified CRC deaths) were included in the study. A positive association between BMI and risk of CRC was observed among participants with a BMI greater than 25.0 to 27.5 (AHR, 1.09 [95% CI, 1.03-1.16]), greater than 27.5 to 30.0 (AHR, 1.19 [95% CI, 1.11-1.29]), and greater than 30.0 (AHR, 1.32 [95% CI, 1.19-1.46]) compared with those with a BMI greater than 23.0 to 25.0 (P < .001 for trend), and BMI was associated with a greater increase in risk for colon cancer than for rectal cancer. A similar association between BMI and CRC-related death risk was observed among participants with a BMI greater than 27.5 (BMI >27.5-30.0: AHR, 1.18 [95% CI, 1.04-1.34]; BMI >30.0: AHR, 1.38 [95% CI, 1.18-1.62]; P < .001 for trend) and was present among men with a BMI greater than 30.0 (AHR, 1.87 [95% CI, 1.49-2.34]; P < .001 for trend) but not among women (P = .15 for trend) (P = .02 for heterogeneity).

Conclusions and Relevance

In this cohort study that included a pooled analysis of 17 cohort studies comprising participants across Asia, a positive association between BMI and CRC incidence and related mortality was found. The risk was greater among men and participants with colon cancer. These findings may have implications to better understand the burden of obesity on CRC incidence and related deaths in the Asian population.

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Role of body mass index and weight change in the risk of cancer: A systematic review and meta-analysis of 66 cohort studies

Background

This study was designed to evaluate the effects of body mass index (BMI) and weight change on the risk of developing cancer overall and cancer at different sites.

Methods

We searched PubMed and other databases up to July 2023 using the keywords related to 'risk', 'cancer', 'weight', 'overweight', and 'obesity'. We identified eligible studies, and the inclusion criteria encompassed cohort studies in English that focused on cancer diagnosis and included BMI or weight change as an exposure factor. Multiple authors performed data extraction and quality assessment, and statistical analyses were carried out using RevMan and R software. We used random- or fixed-effects models to calculate the pooled relative risk (RR) or hazard ratio along with 95% confidence intervals (CIs). We used the Newcastle-Ottawa Scale to assess study quality.

Results

Analysis included 66 cohort studies. Compared to underweight or normal weight, overweight or obesity was associated with an increased risk of endometrial cancer, kidney cancer, and liver cancer but a decreased risk of prostate cancer and lung cancer. Being underweight was associated with an increased risk of gastric cancer and lung cancer but not that of postmenopausal breast cancer or female reproductive cancer. In addition, weight loss of more than five kg was protective against overall cancer risk.

Conclusions

Overweight and obesity increase the risk of most cancers, and weight loss of >5 kg reduces overall cancer risk. These findings provide insights for cancer prevention and help to elucidate the mechanisms underlying cancer development.

Registration

Reviewregistry1786.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Metabolic profile predicts incident cancer: A large-scale population study in the UK Biobank

BACKGROUND AND AIMS

Analyses to predict the risk of cancer typically focus on single biomarkers, which do not capture their complex interrelations. We hypothesized that the use of metabolic profiles may provide new insights into cancer prediction.

METHODS

We used information from 290,888 UK Biobank participants aged 37 to 73 years at baseline. Metabolic subgroups were defined based on clustering of biochemical data using an artificial neural network approach and examined for their association with incident cancers identified through linkage to cancer registry. In addition, we evaluated associations between 38 individual biomarkers and cancer risk.

RESULTS

In total, 21,973 individuals developed cancer during the follow-up (median 3.87 years, interquartile range [IQR] = 2.03-5.58). Compared to the metabolically favorable subgroup (IV), subgroup III (defined as "high BMI, C-reactive protein & cystatin C") was associated with a higher risk of obesity-related cancers (hazard ratio [HR] = 1.26, 95 % CI = 1.21 to 1.32) and hematologic-malignancies (e.g., lymphoid leukemia: HR = 1.83, 95%CI = 1.44 to 2.33). Subgroup II ("high triglycerides & liver enzymes") was strongly associated with liver cancer risk (HR = 5.70, 95%CI = 3.57 to 9.11). Analysis of individual biomarkers showed a positive association between testosterone and greater risks of hormone-sensitive cancers (HR per SD higher = 1.32, 95%CI = 1.23 to 1.44), and liver cancer (HR = 2.49, 95%CI =1.47 to 4.24). Many liver tests were individually associated with a greater risk of liver cancer with the strongest association observed for gamma-glutamyl transferase (HR = 2.40, 95%CI = 2.19 to 2.65).

CONCLUSIONS

Metabolic profile in middle-to-older age can predict cancer incidence, in particular risk of obesity-related cancer, hematologic malignancies, and liver cancer. Elevated values from liver tests are strong predictors for later risk of liver cancer.

Pathogenesis, Murine Models, and Clinical Implications of Metabolically Healthy Obesity

Although obesity is commonly associated with numerous cardiometabolic pathologies, some people with obesity are resistant to detrimental effects of excess body fat, which constitutes a condition called “metabolically healthy obesity” (MHO). Metabolic features of MHO that distinguish it from metabolically unhealthy obesity (MUO) include differences in the fat distribution, adipokine types, and levels of chronic inflammation. Murine models are available that mimic the phenotype of human MHO, with increased adiposity but preserved insulin sensitivity. Clinically, there is no established definition of MHO yet. Despite the lack of a uniform definition, most studies describe MHO as a particular case of obesity with no or only one metabolic syndrome components and lower levels of insulin resistance or inflammatory markers. Another clinical viewpoint is the dynamic and changing nature of MHO, which substantially impacts the clinical outcome. In this review, we explore the pathophysiology and some murine models of MHO. The definition, variability, and clinical implications of the MHO phenotype are also discussed. Understanding the characteristics that differentiate people with MHO from those with MUO can lead to new insights into the mechanisms behind obesity-related metabolic derangements and diseases.

Prolonged or Transition to Metabolically Unhealthy Status, Regardless of Obesity Status, Is Associated with Higher Risk of Cardiovascular Disease Incidence and Mortality in Koreans

The risk of chronic disease and mortality may differ by metabolic health and obesity status and its transition. We investigated the risk of cardiovascular disease (CVD) and cancer incidence and mortality according to metabolic health and obesity status and their transition using the nationally representative Korea National Health and Nutrition Examination Survey (KNHANES) and the Ansan-Ansung (ASAS) cohort of the Korean Genome and Epidemiology Study. Participants that agreed to mortality linkage (n = 28,468 in KNHANES and n = 7530 adults in ASAS) were analyzed (mean follow-up: 8.2 and 17.4 years, respectively). Adults with no metabolic risk factors and BMI <25 or ≥25 kg/m2 were categorized as metabolically healthy non-obese (MHN) or metabolically healthy obese (MHO), respectively. Metabolically unhealthy non-obese (MUN) and metabolically unhealthy obese (MUO) adults had ≥1 metabolic risk factor and a BMI < or ≥25 kg/m2, respectively. In KNHANES participants, MUN, and MUO had higher risks for cardiovascular mortality, but not cancer mortality, compared with MHN adults. MHO had 47% and 35% lower risks of cancer mortality and all-cause mortality, respectively, compared to MHN. Similar results were observed in the ASAS participants. Compared to those persistently MHN, the risk of CVD was greater when continuously MUN or MUO. Transitioning from a metabolically healthy state to MUO also increased the risk of CVD. Few associations were found for cancer incidence. Using a nationally representative cohort and an 18-year follow-up cohort, we observed that the risk of CVD incidence and mortality and all-cause mortality, but not cancer incidence or mortality, increases with a continuous or a transition to an unhealthy metabolic status in Koreans.

Metabolic phenotypes and risk of colorectal cancer: a systematic review and meta-analysis of cohort studies

BACKGROUND

The association of obesity with colorectal cancer (CRC) may vary depending on metabolic status.

OBJECTIVE

This meta-analysis aimed to investigate the combined impacts of obesity and metabolic status on CRC risk.

METHODS

The Scopus, PubMed, and web of sciences databases were systematically searched up to Jun 2021 to find all eligible publications examining CRC risk in individuals with metabolically unhealthy normal-weight (MUHNW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUHO) phenotypes.

RESULTS

A total of 7 cohort studies with a total of 759,066 participants were included in this meta-analysis. Compared with healthy normal-weight people, MUHNW, MHO, and MUHO individuals indicated an increased risk for CRC with a pooled odds ratio of 1.19 (95% CI = 1.09-1.31) in MUHNW, 1.14 (95% CI = 1.06-1.22) in MHO, and 1.24 (95% CI = 1.19-1.29) in MUHO subjects. When analyses were stratified based on gender, associations remained significant for males. However, the elevated risk of CRC associated with MHO and MUHO was not significant in female participants.

CONCLUSIONS

The individuals with metabolic abnormality, although at a normal weight, have an increased risk for CRC. Moreover, obesity is associated with CRC irrespective of metabolic status.

Multivariate Investigation of Toxic and Essential Metals in the Serum from Various Types and Stages of Colorectal Cancer Patients

Colorectal cancer (CRC) is currently one of the most frequent malignant neoplasms, ranking 3rd in incidence and 2nd in mortality both in the USA and across the world. The pathogenesis of CRC is a complex interaction between genetic susceptibility and environmental factors such as exposure to metals. Therefore, the present study was intended to assess the imbalances in the concentrations of selected essential/toxic elements (Pb, Cr, Fe, Zn, As, Cd, Cu, Se, Ni, and Hg) in the serum of newly diagnosed colorectal carcinoma patients (n = 165) in comparison with counterpart controls (n = 151) by atomic absorption spectrometry after wet-acid digestion method. Serum carcinoembryonic antigen (CEA) of the CRC patients was determined using immunoradiometric method. Body mass index (BMI) which is an established risk factor for CRC was also calculated for patients and healthy controls. Conversely, average Ni (2.721 μg/g), Cd (0.563 μg/g), As (0.539 μg/g), and Pb (1.273 μg/g) levels were significantly elevated in the serum of CRC patients compared to the healthy donors, while the average Se (7.052 μg/g), Fe (15.67 μg/g), Cu (2.033 μg/g), and Zn (8.059 μg/g) concentrations were elevated in controls. The correlation coefficients between the elements in the cancerous patients demonstrated significantly dissimilar communal relationships compared with the healthy subjects. Significant differences in the elemental levels were also showed for CRC types (primary colorectal lymphoma, gastrointestinal stromal tumor, and adenocarcinoma) and CRC stages (stage-I, stage-II, stage-III, and stage-IV) among the patients. Majority of the elements demonstrated perceptible disparities in their levels based on dietary, habitat, gender, and smoking habits of the malignant patients and healthy subjects. Multivariate methods revealed noticeably divergent apportionment among the toxic/essential elements in the cancerous patients than the healthy counterparts. Overall, the study showed significantly divergent distribution and associations of the essential and toxic elemental levels in the serum of the CRC patients in comparison with the healthy donors.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis treatment and follow-up of patients with localised colon cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of localised colon cancer was published in 2020. It was decided by both the ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special virtual guidelines meeting in March 2021 to adapt the ESMO 2020 guidelines to take into account the ethnic differences associated with the treatment of localised colon cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with localised colon cancer representing the oncological societies of Japan (JSMO), China (CSCO), India (ISMPO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug availability and reimbursement situations in the different Asian countries.

Metabolically healthy overweight/obesity and cancer risk: A representative cohort study in Taiwan

OBJECTIVE

Many cancers are caused by overweight; however, cancer risk varies among individuals with obesity. Few studies are addressing the relationship between metabolic obesity phenotypes and cancer. This study investigates the association between metabolically healthy overweight (MHOW) or metabolically healthy obesity (MHO) and cancer incidence.

METHODS

In a nationwide, representative community-based prospective cohort study, 5734 Taiwanese adults were classified into eight phenotypes according to body mass index (underweight <18.5; normal weight 18.5-23.9; overweight 24-26.9; and obese ≥27 kg/m²) and metabolic status (healthy/unhealthy). Participants with healthy cardiometabolic blood profiles included in the metabolic syndrome criteria and an absence of hypertension, diabetes, and hyperlipidemia were considered metabolically healthy. We used the Cox proportional hazards models to estimate the adjusted hazard ratio (HR) and 95% confidence intervals (95% CI).

RESULTS

During 73,389 person-years of follow-up, 428 incident cancers were identified. Compared to the participants with metabolically healthy normal weight, participants with MHOW (adjusted HR 1.39, 95% CI, 0.90-2.13) or MHO (adjusted HR 1.07, 95% CI, 0.51-2.22) had a tendency toward a higher risk of cancer. These associations were stronger in MHOW (adjusted HR 1.77, 95% CI, 1.09-2.86) or MHO (adjusted HR 1.39, 95% CI, 0.66-2.93) participants younger than 65 years.

CONCLUSIONS

This study was the first to investigate the impact of metabolic obesity phenotype on the incidence of cancer in the Taiwanese population. Even in the absence of metabolic abnormalities, overweight, and obesity may cause a modest increase in the risk of developing cancer.

Untreated Hypertension and Subsequent Incidence of Colorectal Cancer: Analysis of a Nationwide Epidemiological Database

Background

Studies of the association of hypertension with incident colorectal cancer (CRC) may have been confounded by including individuals taking antihypertensive medication, at high risk for CRC (ie, colorectal polyps and inflammatory bowel disease), or with shared risk factors (eg, obesity and diabetes). We assessed whether adults with untreated hypertension are at higher risk for incident CRC compared with those with normal blood pressure (BP), and whether any association is evident among individuals without obesity or metabolic abnormalities.

Methods and Results

Analyses were conducted using a nationwide health claims database collected in the JMDC Claims Database between 2005 and 2018 (n=2 220 112; mean age, 44.1±11.0 years; 58.4% men). Participants who were taking antihypertensive medications or had a history of CRC, colorectal polyps, or inflammatory bowel disease were excluded. Each participant was categorized as having normal BP (systolic BP [SBP]<120 mm Hg and diastolic BP [DBP] <80 mm Hg, n=1 164 807), elevated BP (SBP 120–129 mm Hg and DBP <80 mm Hg, n=341 273), stage 1 hypertension (SBP 130–139 mm Hg or DBP 80–89 mm Hg, n=466 298), or stage 2 hypertension (SBP ≥140 mm Hg or DBP ≥90 mm Hg, n=247 734). Over a mean follow‐up of 1112±854 days, 6899 incident CRC diagnoses occurred. After multivariable adjustment, compared with normal BP, hazard ratios for incident CRC were 0.93 (95% CI, 0.85–1.01) for elevated BP, 1.07 (95% CI, 0.99–1.15) for stage 1 hypertension, and 1.17 (95% CI, 1.08–1.28) for stage 2 hypertension. The hazard ratios for incident CRC for each 10‐mm Hg‐higher SBP or DBP were 1.04 (95% CI, 1.02–1.06) and 1.06 (95% CI, 1.03–1.09), respectively. These associations were present among adults who did not have obesity, high waist circumference, diabetes, or dyslipidemia.

Conclusions

Higher SBP and DBP, and stage 2 hypertension are associated with a higher risk for incident CRC, even among those without shared risk factors for CRC. BP measurement could identify individuals at increased risk for subsequent CRC.

Association between metabolic syndrome and its components and incident colorectal cancer in a prospective cohort study

BACKGROUND

Metabolic syndrome (MetS) has been identified as a contributor to cancer development. However, reports concerning the association between MetS and colorectal cancer (CRC) have been inconsistent. This study investigated whether MetS, its components, and the number of components increase the risk of CRC.

METHODS

This was a prospective cohort study of 41,837 participants recruited from August 2002 to December 2014 from the National Cancer Center in South Korea. The participants were followed until December 2017 to identify incident CRC cases. The participants underwent laboratory tests at the baseline. Additionally, a self-administered questionnaire collected information concerning lifestyle and general characteristics at the baseline. A Cox proportional hazards model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) to explore the association between MetS and its components and CRC risk after adjustments for confounding variables.

RESULTS

In total, 128 incident CRC cases were identified during the follow-up period. An increased CRC risk was found among participants with MetS (HR, 1.63; 95% CI, 1.08-2.44). Additionally, elevated blood pressure (HR, 1.50; 95% CI, 1.05-2.15) and a high fasting glucose level (HR, 1.80; 95% CI, 1.23-2.63) were associated with an elevated risk of CRC. Notably, an increased risk was identified among participants with abdominal obesity coexisting with another component of MetS.

CONCLUSIONS

These results suggest that MetS is a risk factor for CRC. Greater emphasis should be placed on the importance of CRC screening among individuals with abdominal obesity coexisting with another component of MetS.

LAY SUMMARY

Colorectal cancer (CRC) ranks as the third most common cancer type in terms of incidence. Metabolic syndrome (MetS) has been identified as a contributor to cancer development. However, the association between MetS and CRC remains controversial because of a lack of consistent findings in previous studies. In this study, the National Cholesterol Education Program's Adult Treatment Panel III guidelines are used for the diagnosis of MetS. MetS is found to be a predictor of CRC. Additionally, the importance of CRC screening among individuals with 2 components of MetS should be emphasized.

Prophylactic mesh placement at index permanent end colostomy creation to prevent parastomal hernia-an updated meta-analysis

BACKGROUND

Debate persists regarding the efficacy of prophylactic mesh insertion (PMI) at index permanent stoma creation to reduce the rate of parastomal hernia (PSH). This meta-analysis aimed to appraise all the latest evidence from newly published randomized controlled trials (RCTs) on PMI for PSH prevention.

METHODS

PubMed, EMBASE, and Cochrane databases were searched for relevant articles from inception until November 2020. All RCTs that reported on PMI at end colostomy creation with ≥ 12 months follow-up were included. The primary objective was the rate of clinical and radiological PSH while secondary objectives included number of PSH requiring repair and stoma (or mesh)-related complications. Random effects models were used to calculate pooled effect size estimates. Sensitivity analyses were also performed.

RESULTS

Eleven RCTs were included capturing 1097 patients. The mean (SD) age was 67.9 (±9.4) years. On random effects analysis, prophylactic mesh appeared to reduce the rate of both clinical (OR = 0.27, 95% CI = 0.12 to 0.61, p = 0.002) and radiological (OR = 0.39, 95% CI = 0.24 to 0.65, p = 0.0002) PSH. However, there was no difference in number of PSH requiring repair or stoma-related complications. On sensitivity analysis, when focusing on low-risk of bias studies, the benefit of prophylactic mesh in the retrorectus space was lost for both clinical (OR = 0.97, 95% CI = 0.62 to 1.51, p = 0.89) and radiological PSH (OR = 0.74, 95% CI = 0.46 to 1.18, p = 0.20).

CONCLUSION

PMI may reduce the rate of subsequent PSH. However, further studies are required to confirm these findings and to establish the optimal mesh position and shape before definite recommendations can be made.

Narrative review of the influence of diabetes mellitus and hyperglycemia on colorectal cancer risk and oncological outcomes

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Diabetes mellitus and hyperglycemia significantly affect the incidence and prognosis of colorectal cancer.

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Evidence of the effects of metformin remain controversial in cancer prognosis.

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Potential molecular mechanisms by which DM and hyperglycemia affects cancer risk.

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Potential roles of glucose modulation in CRC therapy.

Diabetes mellitus (DM) and hyperglycemia have been shown to have significant effects on the incidence, chemoresistance, and prognosis of colorectal cancer (CRC), as well as the outcomes of localized and metastatic CRC. Inflammation and endocrine effects may act as central mechanisms of DM and cancer and stimulate the insulin‐like growth factor 1–phosphoinositide 3-kinase–Akt–mammalian target of rapamycin (IGF-1–PI3K–AKT–mTOR) pathway. Dysregulation of the AMP-activated protein kinase (AMPK) pathway leads to metabolic imbalance and indicates cancer risk. The use of metformin for chemoprevention has been shown to reduce CRC and adenoma incidence through the upregulation of AMPK, which causes cell cycle arrest in the Gap 1–S (G1–S) phase and inhibits the mTOR pathway, even potentially reversing the epithelial–mesenchymal transition. However, evidence of the effects of metformin remain controversial in cancer prognosis. Several genes, such as transcription factor 7-like 2(TCF7L2), tumor protein P53 inducible nuclear protein 1(TP53INP1), gremlin 1 (GREM1), and potassium voltage-gated channel subfamily Q member 1(KCNQ1), are pleiotropically related to DM as well as cancer risk and prognosis. Epigenetic modification of members of the Let-7 family such as miR-497, miR-486, and miR-223 is strongly associated with impaired glucose tolerance and CRC risk. Herein we review the pathophysiological and epidemiological evidence as well as potential underlying molecular mechanisms by which DM and hyperglycemia affect CRC risk. We also suggest potential roles of glucose modulation in CRC therapy and propose an agenda for future research and clinical practice.

The association between hypertension and colorectal cancer: a meta-analysis of observational studies

The relationship between hypertension and risk of colorectal cancer (CRC) is unclear. This meta-analysis aims to explore the association between them. Six databases were searched for studies published before August 2019. The pooled relative risk (RR) and 95% confidence intervals (CIs) were calculated to estimate the association between the hypertension and CRC risk. A total of 2841 potentially relevant articles were obtained, and 25 studies with a pooled 1.95 million participants were finally included in the meta-analysis. These results suggested a positive association between hypertension and risk of CRC with a pooled RR of 1.15 (95% CI: 1.08, 1.23). Male patients with hypertension had a 13% (95% CI: 1.06, 1.20) increased risk of CRC. The risk of colon cancer and rectal cancer in male patients was 1.17 (95% CI: 1.01, 1.36) and 1.35 (95% CI: 1.04, 1.74), respectively, while no association between hypertension and the risk of CRC in females was elucidated. This meta-analysis demonstrated that a positive association between hypertension and CRC exists, with male patients having a higher risk of developing CRC than female patients.

Effect of Metabolic Health and Obesity Phenotype on the Risk of Pancreatic Cancer: A Nationwide Population-Based Cohort Study

BACKGROUND

Recently, a few studies have reported different results regarding the relationship between metabolic health and obesity phenotype and several cancers. We examined the effects of metabolic health and obesity phenotype on pancreatic cancer using a nationwide population-based cohort database.

METHODS

Using the Korean National Health Insurance Service-Health Screening Cohort, we enrolled 347,434 Korean adults who underwent a health examination between 2009 and 2010 and were followed until 2015. This population was divided into four groups based on metabolically healthy status and body mass index (BMI): metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO).

RESULTS

Over a median follow-up of 6.1 (5.5-6.5) years, 886 individuals were diagnosed with pancreatic cancer. The adjusted HRs for incident pancreatic cancer were 1.52 [95% confidence interval (CI) 1.27-1.81] and 1.34 (95% CI, 1.12-1.61) for the MUNW and MUO phenotypes (compared with the MHNW phenotype) after adjusting for various confounding factors. However, compared with the MHNW phenotype, the MHO phenotype did not show an elevated risk of pancreatic cancer. Moreover, the HR for pancreatic cancer gradually increased with an increase in number of metabolically unhealthy components, even after adjusting for BMI (P _trend < 0.001).

CONCLUSIONS

Regardless of BMI, metabolically unhealthy phenotype demonstrated significantly increased risk of pancreatic cancer, whereas obese individuals with metabolically healthy phenotype did not.

IMPACT

These findings suggest that metabolically unhealthy phenotype might represent a potential risk factor for pancreatic cancer occurrence independent of obesity.

Diagnostic accuracy of administrative database for bile duct cancer by ICD-10 code in a tertiary institute in Korea

BACKGROUND

Administrative database provides valuable information for large cohort studies, especially when tissue diagnosis is rather difficult such as the diagnosis for bile duct cancer (BDC). The aim of this study was to evaluate the diagnostic accuracy of administrative database for BDC by International Classification of Diseases (ICD)-10 codes in a tertiary institute.

METHODS

BDC and control groups were collected from 2003 to 2016 at Seoul National University Bundang Hospital. Cases of BDC were identified in the National Health Insurance Service (NHIS) database by ICD 10-code supported by V code. The control group was selected from cases without ICD-10 codes for BDC. A definite or possible diagnosis was defined according to pathologic reports. Medical records, images, and pathology reports were analyzed to evaluate ICD-10 codes for BDC. Sensitivity, specificity, positive predictive value, and negative predictive value for BDC were analyzed according to diagnostic criteria and cancer locations.

RESULTS

A total of 1707 patients with BDC and 1707 controls were collected. Among those with BDC, 1320 (77.3%) were diagnosed by definite criteria. Most (99.4%) of them had adenocarcinoma. Rate of definite diagnosis was the highest for ampulla of Vater (88.9%), followed by that for extrahepatic (84.9%) and intrahepatic (68.3%) BDCs. False positive cases commonly had hepatocellular carcinomas. For overall diagnosis of BDC, sensitivity, specificity, positive predictive value, and negative predictive value were 99.94%, 98.33%, 98.30%, and 99.94%, respectively. Diagnostic accuracies were similar regardless of diagnostic criteria or tumor locations.

CONCLUSIONS

Administrative database for BDC collected according to ICD-10 code with V code shows good accuracy.

Metabolic health is a determining factor for incident colorectal cancer in the obese population: A nationwide population-based cohort study

Background

The association of the risk of colorectal cancer (CRC) with obesity or obesity‐induced metabolic disturbances remains controversial. We assessed the association of metabolic health status with incident CRC among subjects with obesity.

Methods

This study included 319,397 subjects from the Korean National Health Insurance Service‐National Health Screening Cohort. Transitions in metabolic health status and obesity were examined during 2009–2010 and 2011–2012. We categorized subjects with obesity into four separate groups according to their dynamic metabolic health status: metabolically healthy obesity (MHO), MHO to metabolically unhealthy obesity (MUO), MUO to MHO, and stable MUO. Subjects were followed up from 2009 to 2015 for incident CRC.

Results

The stable MHO group showed no increased risk of incident CRC (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.83–1.14). However, the MHO to MUO group had a higher risk of incident CRC than the stable metabolically healthy nonobese (MHNO) group (HR, 1.34; 95% CI, 1.15–1.57). Among patients with MUO at baseline, those in the subgroup who transitioned to MHO group were not at increased risk of CRC (HR, 1.06; 95% CI, 0.91–1.25), whereas those who remained in the stable MUO group had a higher risk of incident CRC than those in the stable MHNO group (HR, 1.29; 95% CI, 1.19–1.41).

Conclusions

The transition of metabolic health was a determining factor for CRC among subjects with obesity. Hence, maintenance or recovery of metabolic health should be addressed to prevent CRC in individuals with obesity.

The association between metabolically healthy obesity and risk of cancer: A systematic review and meta-analysis of prospective cohort studies

The risk of cancer among adults with metabolically healthy obesity (MHO) has not yet been established. We systematically searched from inception to 15 March 2020. We included prospective cohort studies that compared participants with MHO and participants with metabolically healthy non-obesity (MHNO) for incidence of any type of cancer. Benign tumors, cancer mortality or cancer prognosis were not in the scope of our analysis. The Newcastle-Ottawa Scale was used for quality assessment. Ultimately, eight studies with a total of 12 542 390 participants were included. The pooled meta-analysis using random effect model showed participants with MHO demonstrated a significantly increased risk of developing cancer (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.05 to 1.23; and I² = 39%) than those with MHNO. The subgroup analysis revealed a higher pooled estimate (OR, 1.17; 95% CI, 1.01-1.35; and I² = 56%) in comparison with metabolically healthy normal weight. No evidence of effect modification by age, sex, ethnicity, smoking, sample size or length of follow-up was found. In conclusion, the present study reports a positive association between MHO and cancer incidence. All individuals with obesity, even in the absence of metabolic dysfunction, should be encouraged to lose weight.

Colorectal Cancer Risks According to Sex Differences in Patients With Type II Diabetes Mellitus: A Korean Nationwide Population-Based Cohort Study

INTRODUCTION:

Developing colorectal cancer (CRC) poses challenges for patients with type II diabetes mellitus (T2DM). We investigated CRC risk factors in patients with T2DM.

METHODS:

We retrospectively collected data from the National Health Insurance Corporation database, comprising approximately 97% of the Korean population. T2DM and CRC were defined according to International Classification of Disease codes (10th Revision) and claims data. Obesity was defined using body mass index (BMI); abdominal obesity was defined according to waist circumference. Other variables were defined using demographic, anthropometric, and laboratory data.

RESULTS:

Overall, 2,591,149 patients with T2DM were analyzed. During the follow-up period (median, 5.4 years), 24,236 CRC cases were identified. Aging (≥70 years), male sex, smoking, alcohol consumption, hypertension, and insulin and/or sulfonylurea use were significant risk factors for CRC. In males, smoking and alcohol consumption were more likely to lead to CRC, whereas a BMI increase was a more significant risk factor in females. Females with a BMI ≥ 25 kg/m² and abdominal obesity were associated with an 18% increased risk of CRC compared with patients with normal weight and normal waist circumference (hazard ratio = 1.184, 95% confidence interval 1.123–1.25), whereas male patients with a BMI ≥ 25 kg/m² and abdominal obesity were associated with an 8% increased risk (hazard ratio = 1.087, 95% confidence interval 1.049–1.127).

DISCUSSION:

Patients had CRC risk factors that differed according to sex. Smoking and heavy alcohol consumption were risks of CRC in males. Female patients with a BMI ≥ 25 kg/m² and abdominal obesity were at a higher risk of developing CRC than males.

Risk factors including night shift work of colorectal polyp

Background

The destruction of circadian rhythms by night shift work affects major circadian genes, which are known to play a role in advancing or killing the cell cycle through tumor suppressor genes. To find out whether night shift work affects the incidence of colorectal cancer, which was found to be associated with long-term night shift work in previous studies, we surveyed effect of night shift work on colorectal polyps that have a higher incidence than colorectal cancer and can progress to colorectal cancer.

Methods

To examine the correlation between rotating night shifts and colorectal polyps, a survey was conducted with 299 men aged 40–60 years from two university hospitals. We examined lifestyle, work history, work patterns, and colonoscopy results. The differences in prevalence among the groups was compared, and prevalence ratio (PR) was calculated via generalized linear modeling.

Results

The prevalence of colorectal polyps in night shift and non-shift workers were 53.0% and 33.5%, respectively. After adjusting for age, smoking status, dietary habits, family history of colorectal cancer, obesity, job type, night shift work (PR: 1.13, 95% CI: 1.02–1.25) was a risk factor of colorectal polyps.

Conclusions

The risk of colorectal polyps was greater in night shift workers than non-shift workers. Also risk of colorectal polyp was higher in older group. Our study investigated colorectal polyp instead of colorectal cancer and lacks information about types and gene mutations of colorectal polyps. Further study is needed to clarify effect of night shift work on development of colorectal cancer.

Temporal trajectories of accompanying comorbidities in patients with type 2 diabetes: a Korean nationwide observational study

Type 2 diabetes mellitus is a major concern globally and well known for increasing risk of complications. However, diabetes complications often remain undiagnosed and untreated in a large number of high-risk patients. In this study based on claims data collected in South Korea, we aimed to explore the diagnostic progression and sex- and age-related differences among patients with type 2 diabetes using time-considered patterns of the incidence of comorbidities that evolved after a diagnosis of type 2 diabetes. This study compared 164,593 patients who met the full criteria for type 2 diabetes with age group-, sex-, encounter type-, and diagnosis date-matched controls who had not been diagnosed with type 2 diabetes. We identified 76,423 significant trajectories of four diagnoses from the dataset. The top 30 trajectories with the highest average relative risks comprised microvascular, macrovascular, and miscellaneous complications. Compared with the trajectories of male groups, those of female groups included relatively fewer second-order nodes and contained hubs. Moreover, the trajectories of male groups contained diagnoses belonging to various categories. Our trajectories provide additional information about sex- and age-related differences in the risks of complications and identifying sequential relationships between type 2 diabetes and potentially complications.

Risk Factors for Colorectal Cancer in Korea: A Population-Based Retrospective Cohort Study

Purpose

The incidence of colorectal cancer in Korea has recently increased, making it the second most common cancer in men and the third most common cancer in women. Risk factors for colorectal cancer have been studied worldwide, but risk factors specific for the Korean population have not been established. In this study, we investigated incidence trends and risk factors of colorectal cancer in Korea.

Methods

A total of 8,846,749 subjects were included. Colorectal cancer incidence was investigated using Korea National Health Insurance Service claim data from 2004 to 2014. Colorectal cancer diagnoses were obtained by evaluating colorectal cancer diagnostic codes and the cancer registry for cost sharing. Risk factor identification for colorectal cancer was obtained from National Health Examination data from 2004 to 2005. Cox proportional hazard model statistical analysis was used to determine risk factors of colorectal cancer.

Results

The incidence of colorectal cancer gradually increased from 2006 to 2014 (from 45.4/100,000 to 54.5/100,000). There was a predominance among men (1.47:1), but incidence trends were similar in both sexes. Old age, high body mass index, and no history of colonoscopy were identified as risk factors in both sexes. High fasting blood glucose, familial history of cancer, frequent alcohol intake, and current smoker were identified as risk factors, especially in men.

Conclusion

The incidence of colorectal cancer has been increasing in Korea. Colonoscopy screening was a protective factor for colorectal cancer, and active use of colonoscopy may reduce incidence. Early diagnosis and care are important, particularly for the high-risk group.

Accuracy of an administrative database for pancreatic cancer by international classification of disease 10th codes: A retrospective large-cohort study

BACKGROUND

Korean National Health Insurance (NHI) claims database provides large-cohort. However, studies regarding accuracy of administrative database for pancreatic cancer (PC) have not been reported. We aimed to identify accuracy of NHI database regarding PC classified by international classification of disease (ICD)-10 codes.

AIM

To identify the accuracy and usefulness of administrative database in PC and the accurate ICD codes for PC with location.

METHODS

Study and control groups were collected from 2003 to 2016 at Seoul National University Bundang Hospital. Cases of PC were identified in NHI database by international classification of diseases, 10th revision edition (ICD-10 codes) supported with V codes. V code is issued by medical doctors for covering 95% of medical cost by Korean government. According to pathologic reports, definite or possible diagnoses were defined using medical records, images, and pathology.

RESULTS

A total of 1846 cases with PC and controls were collected. Among PC, only 410 (22.2%) cases were identified as specific cancer sites including head in 234 (12.7%) cases, tail in 104 (5.6%) cases and body in 72 (3.9%) cases. Among PC, 910 (49.3%) cases were diagnosed by definite criteria. Most of these were adenocarcinoma (98.0%). The rates of definite diagnosis of PC were highest in head (70.1%) followed by body (47.2%) and tail (43.3%). False-positive cases were pancreatic cystic neoplasm and metastasis to the pancreas. In terms of the overall diagnosis of PC, sensitivity, specificity, positive predictive value, and negative predictive value were 99.95%, 98.72%, 98.70%, and 99.95%, respectively. Diagnostic accuracy was similar both in terms of diagnostic criteria and tumor locations.

CONCLUSION

Korean NHI claims database collected according to ICD-10 code with V code for PC showed good accuracy.

Impact of obesity and metabolic abnormalities on the risk of metachronous colorectal neoplasia after polypectomy in men

BACKGROUND AND AIM

Obesity and metabolic syndrome are well-known risk factors for the development of metachronous colorectal neoplasia (CRN). However, data on the risks of metachronous CRN among subgroups according to obesity and metabolic status are scarce. Therefore, we aimed to compare the risk of metachronous CRN among men with different obesity and metabolic status.

METHODS

In total, 8059 asymptomatic men who underwent ≥ 1 adenoma removal between 2010 and 2014 and follow-up colonoscopic surveillance until 2017 were categorized into four groups according to obesity and metabolic status: metabolically healthy non-obese (MHNO), metabolically healthy obese (MHO), metabolically unhealthy non-obese (MUNO), and metabolically unhealthy obese (MUO).

RESULTS

Of the 8059 men, 2389 (29.6%), 351 (4.4%), 1986 (24.6%), and 3333 (41.4%) subjects were assigned to the MHNO, MHO, MUNO, and MUO groups, respectively. The mean surveillance interval was 3.5 ± 1.4 years. Compared to the MHNO group, the risk of metachronous advanced CRN was significantly increased in the MUO group (adjusted hazard ratio [HR] = 1.50; 95% confidence interval [CI]: 1.02-2.19), but not in the MHO and MUNO groups, while the risk of metachronous overall CRN significantly increased in the MUNO (adjusted HR = 1.12; 95% CI: 1.01-1.24) and MUO groups (adjusted HR = 1.17; 95% CI: 1.07-1.29), but not in the MHO group.

CONCLUSIONS

Men who had both obesity and poor metabolic health were found to be at an increased risk of metachronous advanced CRN, suggesting that MUO men may need to undergo more intensive surveillance colonoscopy after polypectomy.

Prevalence and risk factors of colorectal cancer in Asia

Globally, colorectal cancer (CRC) is a substantial public health burden, and it is increasingly affecting populations in Asian countries. The overall prevalence of CRC is reported to be low in Asia when compared with that in Western nations, yet it had the highest number of prevalent cases. This review described the prevalence of CRC in Asia according to the International Agency for Research on Cancer from World Health Organization (WHO) database and summarized its major risk factors. Non-modifiable factors include genetic factors, ethnicity, age, gender, family history and body height; smoking, alcohol drinking, weight, Westernized diet, physical inactivity, chronic diseases and microbiota were involved in environmental factors. These risk factors were separately discussed in this review according to published literature from Asian countries. CRC screening has been playing an important role in reducing its disease burden. Some recommendations on its screening practices have been formulated in guidelines for Asia Pacific countries.

Complementing conventional infectious disease surveillance with national health insurance claims data in the Republic of Korea

Surveillance remains an important tool for timely outbreak detection and response. Many countries, including Korea, have established national infectious disease surveillance systems with clinical notification. We aimed to evaluate the National Health Insurance Claims-based Surveillance (NHICS) compared to conventional passive report-based National Infectious Diseases Surveillance (NIDS). Reported to claimed cases ratios (R/C ratio) were evaluated from monthly notifiable disease cases captured by NIDS and NHICS. The relationships between 26 infectious diseases and each surveillance system were analysed using Pearson's correlation analysis and linear regression. There was an overall increase in R/C ratio from 2010-2017 (0.37 to 0.78). In 22 infectious diseases, there was a correlation between NIDS and NHICS. Moreover, claim-based surveillance showed less fluctuating disease incidence rates than report-based surveillance for specific infectious diseases, such as varicella, mumps, and scarlet fever. However, for infectious diseases with episodic outbreaks or low incidence, it was difficult to assess NHICS usefulness. Claim-based surveillance is less affected by limitations of conventional report-based surveillance systems, such as reporting rate. Given delays in claim systems, a claim-based surveillance is expected to be complementary to conventional systems for the detection of various infectious diseases with the advancement of bio-information technology.

Association between blood pressure and risk of cancer development: a systematic review and meta-analysis of observational studies

With the exception of renal cell carcinoma, studies assessing the association between hypertension and other cancers are inconsistent. We conducted a meta-analysis to assess this evidence. We included observational studies investigating the association between any definition of hypertension or systolic and diastolic blood pressure and risk of any cancer, after searching PubMed until November 2017. We calculated summary relative risks (RR) and 95% confidence intervals (CI) using inverse-variance weighted random effects methods. A total of 148 eligible publications were identified out of 39,891 initially screened citations. Considering only evidence from 85 prospective studies, positive associations were observed between hypertension and kidney, colorectal and breast cancer. Positive associations between hypertension and risk of oesophageal adenocarcinoma and squamous cell carcinoma, liver and endometrial cancer were also observed, but the majority of studies did not perform comprehensive multivariable adjustments. Systolic and diastolic blood pressure were positively associated with risk of kidney cancer but not with other cancers. In addition to the previously well-described association between hypertension and risk of kidney cancer, the current meta-analysis suggested that hypertensive individuals may also be at higher risk of colorectal and breast cancer. However, careful interpretation is required as most meta-analyses included relatively small number of studies, several relative risks had weak or moderate magnitude and maybe affected by residual confounding.

Incidence and Risk Factors for Venous Thromboembolism After Spine Surgery in Korean Patients

BACKGROUND

Data regarding the incidence of venous thromboembolism (VTE) after spine surgery are scarce. Identifying ideal candidates for pharmacologic thromboprophylaxis and balancing the risk of thromboembolic complications against the risk of permanent neurologic deficits from a spinal epidural hematoma (SEH) are difficult. Even guidelines cannot suggest the standard of thromboprophylaxis.

OBJECTIVES

This study aimed to identify the incidence of and risk factors for VTE after spine surgery in the Korean population. In addition, the rate of pharmacoprophylaxis and the incidence of SEH after spine surgery were analyzed.

METHODS

The study cohort was generated by extracting patients with disease codes of spine surgery and VTE from the Health Insurance Review & Assessment Service National Inpatient Sample in 2014. After analyzing the incidence of VTE after spine surgery, a univariate comparison was performed to examine the possible relationship between the incidence of VTE and the independent variable. Variables found to be significant were included in a multivariable analysis model for further analysis.

RESULTS

The incidence of VTE was 2.09% among all 21,261 patients who had spine surgery, and prophylaxis was applied to 7.89% of all patients who had spine surgery. Comorbidities and surgery-related risk factors were venous disease, cancer, respiratory disease, prolonged surgery hours, and increased total blood loss. Hospital-related risk factors were the location and hospital size.

CONCLUSIONS

On the basis of the incidence of VTE and the risk factors, more active prophylaxis is suggested for patients in the Korean population who undergo spine surgery.

Optimal Starting Age for Colorectal Cancer Screening in an Era of Increased Metabolic Unhealthiness: A Nationwide Korean Cross-Sectional Study

Background/Aims

The association between metabolic syndrome and colorectal cancer (CRC) has been suggested as one of causes for the increasing incidence of CRC, particularly in younger age groups. The present study examined whether the current age threshold (50 years) for CRC screening in Korea requires modification when considering increased metabolic syndrome.

Methods

We analyzed data from the National Health Insurance Corporation database, which covers ~97% of the population in Korea. CRC risk was evaluated with stratification based on age and the presence/absence of relevant metabolic syndrome components (diabetes, dyslipidemia, and hypertension).

Results

A total of 51,612,316 subjects enrolled during 2014 to 2015 were analyzed. Among them, 19.3% had diabetes, hypertension, dyslipidemia, or some combination thereof. This population had a higher incidence of CRC than did those without these conditions, and this was more prominent in subjects <40 years of age. The optimal cutoff age for detecting CRC, based on the highest Youden index, was 45 years among individuals without diabetes, dyslipidemia, and hypertension. Individuals with at least one of these components of metabolic syndrome had the highest Youden index at 62 years old, but the value was only 0.2. Resetting the cutoff age from 50 years to 45 years achieved a 6% increase in sensitivity for CRC detection among the total population.

Conclusions

Starting CRC screening earlier, namely, at 45 rather than at 50 years of age, may improve secondary prevention of CRC in Korea.

Overweight as an Additional Risk Factor for Colorectal Neoplasia in Lean Population

Background:

Overweight in Thailand is not as common as in Western countries. We sought to evaluate overweight as the additional risk factor that can increase the prediction of colorectal neoplasia (CRN) detection in Thais apart from the Asia-Pacific Colorectal Screening (APCS) score.

Methods:

We prospectively enrolled asymptomatic 338 subjects who underwent screening colonoscopy between November 2016 and September 2017. All risk factors according to APCS, BMI and the presence of metabolic syndrome were collected. Overweight was defined as BMI ≥23 kg/m². By APCS score, subjects were categorized into 1) high-risk and 2) average-risk. Using the combination of APCS score and overweight, subjects were stratified into 4 groups; high-risk with overweight (G1), average-risk with overweight (G2), high-risk with normal weight (G3) average-risk and with normal weight (G4). Logistic regression analysis was used to estimate the risk of detecting CRN.

Results:

The prevalence of CRN in the high-risk subjects was higher than that of in the average-risk subjects (49%vs.32%; OR, 2.00; 95%CI, 1.17-3.41). After adjustment for APCS risk factors and metabolic syndrome, overweight significantly increased the risk of detecting CRN (OR, 2.52; 95%CI, 1.57-4.05). Among the 4 groups, the detection rates of CRN were significantly different (G1=64%, G2=40%, G3=32% and G4=21%, p<0.01). The relative risk of detecting CRN increased when G1 (OR 6.49; 95%CI, 2.87-14.67), and G2 (2.42; 1.39-4.21) were compared with G4.

Conclusions:

In addition to the APCS score, overweight is an independent risk factor for detecting CRN. In Thai population, combining overweight and APCS score may be useful to improve the prediction for CRN.

Validation of Administrative Big Database for Colorectal Cancer Searched by International Classification of Disease 10th Codes in Korean: A Retrospective Big-cohort Study

Background

As the number of big-cohort studies increases, validation becomes increasingly more important. We aimed to validate administrative database categorized as colorectal cancer (CRC) by the International Classification of Disease (ICD) 10th code.

Methods

Big-cohort was collected from Clinical Data Warehouse using ICD 10th codes from May 1, 2003 to November 30, 2016 at Seoul National University Bundang Hospital. The patients in the study group had been diagnosed with cancer and were recorded in the ICD 10th code of CRC by the National Health Insurance Service. Subjects with codes of inflammatory bowel disease or tuberculosis colitis were selected for the control group. For the accuracy of registered CRC codes (C18-21), the chart, imaging results, and pathologic findings were examined by two reviewers. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CRC were calculated.

Results

A total of 6,780 subjects with CRC and 1,899 control subjects were enrolled. Of these patients, 22 subjects did not have evidence of CRC by colonoscopy, computed tomography, magnetic resonance imaging, or positron emission tomography. The sensitivity and specificity of hospitalization data for identifying CRC were 100.00% and 98.86%, respectively. PPV and NPV were 99.68% and 100.00%, respectively.

Conclusions

The big-cohort database using the ICD 10th code for CRC appears to be accurate.

Type 2 diabetes and risk of colorectal cancer in two large U.S. prospective cohorts

Background

Previous studies have shown a positive association between type 2 diabetes (T2D) and colorectal cancer (CRC) risk. However, it is uncertain whether this association differs by duration of T2D or sex. We thus investigated the associations of T2D and its duration with the risk of incident CRC.

Methods

We followed 87,523 women from the Nurses’ Health Study (1980–2012) and 47,240 men from the Health Professionals Follow-up Study (1986–2012). Data on physician-diagnosed T2D was collected at baseline with a questionnaire and updated biennially. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

We documented 3000 CRC cases during up to 32 years of follow-up. Among men, T2D was associated with increased risk of CRC compared to those without T2D (HR: 1.42; 95% CI: 1.12–1.81). This positive association persisted in sensitivity analyses by excluding CRC identified within 1 year of diabetes diagnosis and patients with T2D who used hypoglycaemic medications. Among women, T2D was positively, but not statistically significantly, associated with CRC risk (HR: 1.17; 95% CI: 0.98–1.39).

Conclusions

Our findings support that T2D was associated with a moderately higher risk of developing CRC in men; a weaker, nonsignificant positive association was observed in women.

Influence of Obesity and Metabolic Abnormalities on the Risk of Developing Colorectal Neoplasia

BACKGROUND

Obesity and metabolic syndrome are risk factors for colorectal neoplasia (CRN). However, the association between metabolically healthy obese (MHO) or metabolically unhealthy non-obese (MUNO) status and the risk of CRN remains unclear.

AIMS

We aimed to elucidate the association between MHO or MUNO status and the risk of CRN.

METHODS

A total of 139,023 asymptomatic subjects who underwent a primary screening colonoscopy were categorized into 4 groups according to obesity and metabolic status: metabolically healthy non-obese (MHNO), MHO, MUNO, and metabolically unhealthy obese (MUO).

RESULTS

Mean participant age was 41.0 years, and the proportion of men was 65.3%. Among men, the risk of overall CRN increased in MHO (adjusted odds ratio [AOR] 1.22, 95% confidence intervals [CI] 1.12-1.33), MUNO (AOR 1.25, 95% CI 1.18-1.31), and MUO groups (AOR 1.47, 95% CI 1.40-1.54) compared with the MHNO group, whereas the risk of advanced CRN (ACRN) increased in MUNO (AOR 1.16, 95% CI 1.002-1.33) and MUO groups (AOR 1.49, 95% CI 1.31-1.70), but not in the MHO group (AOR 0.92, 95% CI 0.70-1.21). Moreover, among non-obese men, the risk of overall CRN and ACRN linearly increased with an increasing number of metabolic abnormalities. However, among women, only the MUO group had an increased risk of overall CRN (AOR 1.34, 95% CI 1.21-1.47) and no other significant associations were observed.

CONCLUSIONS

Poor metabolic health, regardless of obesity, is an independent risk factor for CRN in men. Our results suggest that men with metabolic abnormalities should be considered as a high-risk group for colorectal cancer, even if they are not obese.

Secondary Breast, Ovarian, and Uterine Cancers After Colorectal Cancer: A Nationwide Population-Based Cohort Study in Korea

BACKGROUND

The risk of a second primary cancer has increased along with the increasing life expectancies of colorectal cancer survivors.

OBJECTIVE

We aimed to evaluate the incidence rate and risk factors of breast and gynecological (ovarian, uterine cervix/corpus) cancers among female colorectal cancer survivors.

DESIGN

This is a retrospective population-based cohort study.

SETTINGS

This study used data from the National Health Insurance Corporation of Korea.

PATIENTS

Each patient with colorectal cancer diagnosed from 2007 to 2012 was followed until 2015 and compared with age-matched women without colorectal cancer at a 1:5 ratio.

MAIN OUTCOME MEASURES

The primary outcome was de novo breast/gynecological cancer. Patients with available medical checkup data were included in an additional analysis.

RESULTS

We analyzed 56,682 patients with colorectal cancer and 288,119 age-matched noncolorectal cancer controls. The risk of breast/gynecological cancer was higher among patients with colorectal cancer than among controls (HR, 2.91; p < 0.001). The association with colorectal cancer was the highest for ovarian cancer (HR, 6.72), followed by uterine corpus cancer (HR, 3.99), cervical cancer (HR, 2.82), and breast cancer (HR, 1.85). This association remained consistent in the subgroup analysis of medical checkup data (14,190 patients with colorectal cancer, 71,933 controls). Among patients with colorectal cancer, those aged <55 years had a higher risk of breast/gynecological cancers than those aged >55 years (HR, 3.51 vs 2.59), and those with dyslipidemia had a higher risk of breast cancer than those without dyslipidemia (HR, 2.66 vs 2.06).

LIMITATIONS

This was a retrospective, population-based study. A prospectively designed study is needed to validate our conclusions.

CONCLUSIONS

Compared with the general population, patients with colorectal cancer carry a higher risk of developing secondary breast, ovarian, and uterine cancers. See Video Abstract at http://links.lww.com/DCR/A731.

Diabetes, plasma glucose and incidence of colorectal cancer in Chinese adults: a prospective study of 0.5 million people

Background

Diabetes is associated with higher risk of colorectal cancer (CRC). Uncertainty remains about the relevance of duration of diabetes and about the association of blood glucose with CRC risk among individuals without diabetes.

Methods

The prospective China Kadoorie Biobank recruited 512 713 participants in 2004–2008 from 10 diverse areas in China. After 10 years of follow-up, 3024 incident cases of CRC (1745 colon, 1716 rectal) were recorded among 510 136 participants without prior cancer at baseline. Cox regression was used to estimate adjusted HRs for CRC associated with diabetes (previously diagnosed or screen-detected) and, among those without previously diagnosed diabetes, with levels of random plasma glucose (RPG).

Results

Overall 5.8% of participants had diabetes at baseline. Individuals with diabetes had an adjusted HR of 1.18 (95% CI 1.04 to 1.33) for CRC, with similar risk for colon and rectal cancer (1.19 [1.01 to 1.39] vs 1.14 [0.96 to 1.35]). The HRs decreased with longer duration of diabetes (p for trend 0.03). Among those without previously diagnosed diabetes, RPG was positively associated with CRC, with adjusted HRs per 1 mmol/L higher baseline RPG of 1.04 (1.02 to 1.05) for CRC, again similar for colon and rectal cancer (1.03 [1.01to 1.05] and 1.04 [1.02 to 1.06], respectively). The associations of diabetes and RPG appeared stronger in men than in women, but the differences were non-significant (p for heterogeneity 0.3 and 0.2).

Discussion

Among Chinese adults, diabetes and higher blood glucose levels among those without known diabetes are associated with higher risk of CRC.

Updates on Cancer Epidemiology in Korea, 2018

Cancer is a major cause of morbidity and the most common cause of death in Korea. There are currently approximately 200,000 incident cancer cases and 78,000 individuals die from cancer every year. The factors directly related to cancer incidence, including aging, smoking, obesity, and Westernized dietary habits, have been increasing during the past several decades. Since 1999, trends toward increased incidence have been observed for thyroid, breast (in women), colorectal, and prostate cancer. Currently, these trends have changed direction, and the incidence of stomach and liver cancer in both sexes, and cervical cancer in women have continually declined. Although the number of cancer deaths increased by a factor of 2.7 from 1983 to 2016, the age-standardized mortality associated with cancer has been decreasing by 3% every year. The 5-year relative survival rate (RSR) has also improved over the past several decades, especially for stomach, prostate, and breast cancer, which had 5-year RSRs greater than 90% in the most recent report.

Downregulation of RPN2 induces apoptosis and inhibits migration and invasion in colon carcinoma

The morbidity of colorectal cancer (CRC) increases annualy, which accounts to higher mortality worldwide. Therefore, it is important to study the pathogenesis of colon cancer. Ribophorin II (RPN2), part of the N-oligosaccharyltransferase complex, is highly expressed in CRC. In the present study, we investigated whether RPN2 can regulate apoptosis, migration and invasion by RNA interference in CRC and sought to clarify the molecular mechanism involved. Based on previous research, an abnormal high expression of RPN2 was observed in CRC tissues and cell lines by real-time (RT)-PCR, immunohistochemistry (IHC) and western blot analysis. RPN2 knockdown via small RNA interference (siRNA) strategy attenuated the expression of RPN2 at the mRNA and protein levels in vivo, leading to decreased cell viability and increased cell apoptosis. In addition, RNAi-RPN2 effectively arrested the cell cycle at the G0/G1-phase in SW1116 and SW480 cells. Furthermore, the Transwell assay demonstrated that cell migration and invasion abilities were significantly inhibited after cell transfection with RPN2 interference plasmid. The apoptosis-related protein (caspase-3) expression was increased and the cell cycle-related protein (cyclin D1) expression was decreased in the siRNA-RPN2 group. RT-PCR and western blot analysis results indicated that migration- and invasion-related proteins including E-cadherin, matrix metalloproteinases (MMP)-2 and TIMP-2 were markedly regulated by RPN2 siRNA. Phosphorylation levels of signal transducer and activator of transcription (STAT)3 and Janus kinase (JAK)2 were inhibited by RPN2 siRNA. These findings indicated a novel pathway of tumor-promoting activity by RPN2 in CRC, with significant implications for unraveling the tumorigenesis of CRC.