Components of the metabolic syndrome and colorectal cancer risk; a prospective study

Inflammation and cancer: friend or foe?

Chronic inflammation plays a crucial role in the onset and progression of pathologies like neurodegenerative and cardiovascular diseases, diabetes, and cancer, since tumor development and chronic inflammation are linked, sharing common signaling pathways. At least 20% of breast and colorectal cancers are associated with chronic inflammation triggered by infections, irritants, or autoimmune diseases. Obesity, chronic inflammation, and cancer interconnection underscore the importance of population-based interventions in maintaining healthy body weight, to disrupt this axis. Given that the dietary inflammatory index is correlated with an increased risk of cancer, adopting an anti-inflammatory diet supplemented with nutraceuticals may be useful for cancer prevention. Natural products and their derivatives offer promising antitumor activity with favorable adverse effect profiles; however, the development of natural bioactive drugs is challenging due to their variability and complexity, requiring rigorous research processes. It has been shown that combining anti-inflammatory products, such as non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins, with plant-derived products demonstrate clinical utility as accessible adjuvants to traditional therapeutic approaches, with known safety profiles. Pharmacological approaches targeting multiple proteins involved in inflammation and cancer pathogenesis emerge as a particularly promising option. Given the systemic and multifactorial nature of inflammation, comprehensive strategies are essential for long term success in cancer therapy. To gain insights into carcinogenic phenomena and discover diagnostic or clinically relevant biomarkers, is pivotal to understand genetic variability, environmental exposure, dietary habits, and TME composition, to establish therapeutic approaches based on molecular and genetic analysis. Furthermore, the use of endocannabinoid, cannabinoid, and prostamide-type compounds as potential therapeutic targets or biomarkers requires further investigation. This review aims to elucidate the role of specific etiological agents and mediators contributing to persistent inflammatory reactions in tumor development. It explores potential therapeutic strategies for cancer treatment, emphasizing the urgent need for cost-effective approaches to address cancer-associated inflammation.

Metabolic syndrome and risk of colorectal cancer: A Mendelian randomization study

Background

Observational studies have previously demonstrated a significant relationship among both metabolic syndrome (Mets) and colorectal cancer (CRC). Whether there is a causal link remains controversial.

Objective

To clarify whether Mets and their components have a causal effect on colorectal cancer, we have carried out a bidirectional Mendelian randomization analysis (MR).

Methods

This study started from genome-wide association data for Mets and its 5 components (hypertension, waist circumference, fasting blood glucose, serum triglycerides, and serum high-density lipoprotein cholesterol) and colorectal cancer. Mendelian randomization (MR) techniques were used in the study to examine their associations.

Results

After Benjamini-Hochberg multiple corrections, genetically predicted significant causal link exists between WC (waist circumference) and CRC. The OR was 1.35 (95 % CI: 1.08-1.69; p = 0.0096). Other Mets components (HBP, FBG, TG, HDL), on the other hand, found no evidence of a genetic link between CRC and Mets. In addition, MR results showed that CRC was not causally related to either Mets or the components. We get the same result in the validated dataset.

Conclusion

According to the bidirectional MR investigation shows a significant causal relationship among obesity and CRC in the Mets component but no causal relationship in the opposite direction.

Association of Measures of Glucose Metabolism with Colorectal Cancer Risk in Older Chinese: A 13-Year Follow-up of the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy and Meta-Analysis

BACKGRUOUND

Abnormal glucose metabolism is a risk factor for colorectal cancer (CRC). However, association of glycosylated hemoglobin (HbA1c) with CRC risk remains under-reported. We examined the association between glycemic indicators (HbA1c, fasting plasma glucose, fasting insulin, 2-hour glucose, 2-hour insulin, and homeostasis model of risk assessment-insulin resistance index) and CRC risk using prospective analysis and meta-analysis.

METHODS

Participants (n=1,915) from the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy were included. CRC events were identified through record linkage. Cox regression was used to assess the associations of glycemic indicators with CRC risk. A meta-analysis was performed to investigate the association between HbA1c and CRC risk.

RESULTS

During an average of 12.9 years follow-up (standard deviation, 2.8), 42 incident CRC cases occurred. After adjusting for potential confounders, the hazard ratio (95% confidence interval [CI]) of CRC for per % increment in HbA1c was 1.28 (95% CI, 1.01 to 1.63) in overall population, 1.51 (95% CI, 1.13 to 2.02) in women and 1.06 (95% CI, 0.68 to 1.68) in men. No significant association of other measures of glycemic indicators and baseline diabetes with CRC risk was found. Meta-analyses of 523,857 participants including our results showed that per % increment of HbA1c was associated with 13% higher risk of CRC, with the pooled risk ratio being 1.13 (95% CI, 1.01 to 1.27). Subgroupanalyses found stronger associations in women, colon cancer, Asians, and case-control studies.

CONCLUSION

Higher HbA1c was a significant predictor of CRC in the general population. Our findings shed light on the pathology of glucose metabolism and CRC, which warrants more in-depth investigation.

Systemic adiponectin levels in colorectal cancer and adenoma: a systematic review and meta-analysis

BACKGROUND

Obesity is a well-established risk factor in the development of colorectal cancer; however, the mechanism mediating this relationship is not well understood. The adipokine, adiponectin, has an inverse relationship with obesity. Experimental studies have shown adiponectin to have dichotomous inflammatory and tumorigenic roles. Its role in the development of colorectal cancer, including the potential effect of its increase following bariatric surgery, is not yet clear. There are conflicting results from studies evaluating this relationship. This study sought to provide a systematic review and meta-analysis to examine the association between systemic adiponectin levels in patients with colorectal cancer and adenoma.

METHODS

An electronic literature search was performed using PubMed, EMBASE, Web of Science as well as gray literature. Articles were screened for inclusion criteria and assessed for quality using the Newcastle-Ottawa Scale. Pooled mean differences were calculated using a random effects model. Subgroup and meta-regression analyses were performed to identify potential sources of heterogeneity.

RESULTS

Thirty-two observational studies comparing systemic adiponectin in colorectal cancer vs healthy controls were included. Colorectal cancer cases had lower systemic adiponectin levels (overall pooled mean difference = -1.05 μg/ml [95% CI: -1.99; -0.12] p = 0.03); however, significant heterogeneity was present (I2 = 95% p < 0.01). Subgroup and meta- regression analyses results could not identify a source of the significant heterogeneity across the studies.

CONCLUSIONS

Studies suggest a trend towards lower systemic adiponectin levels in colorectal cancer patients, but the heterogeneity observed showed current evidence is not sufficient to definitively draw any conclusions. These data, however, suggest rising adiponectin is unlikely to account for the reported observation of increased CRC following bariatric surgery. Further studies with prospective age, race, and BMI-matched cohorts, and standardized adiponectin measurements may provide a better understanding of this relationship.

Alteration of Metabolic Syndrome Is Associated with the Decreased Risk of Colorectal Cancer

Metabolic syndrome (MetS) can be resolved through active control. We aimed to examine the effect of changes in MetS status on colorectal cancer (CRC) risk. A total of 5,704,611 Korean national insurance beneficiaries that received two consecutive biennial mandatory health exams (2009-2011) were followed-up until 2017. MetS was determined as the presence of at least three of five components. Participants were categorized into four groups according to the change in MetS status; MetS-never, -resolved, -developed, or -persistent. A Cox proportional hazards model adjusted for age, sex, smoking, alcohol drinking, and physical exercise was used. Participants who recovered from MetS had a higher risk of CRC than those free of MetS but had a lower risk than those with persistent MetS (HR: 0.91, 95% CI: 0.86-0.95 vs. HR: 0.75, 95% CI: 0.73-0.78; reference: persistence group). Among the five MetS components, resolving high blood pressure, abdominal obesity, and blood sugar had a preventive effect on CRC prevention, while normalization of lipid profile did not reduce CRC risk independently. Resolving MetS could reduce CRC risk compared to having persistent MetS, indicating the necessity of considering control of MetS as a CRC prevention policy.

Leptin: A Heavyweight Player in Obesity-Related Cancers

Obesity, defined as the abnormal or excessive expansion of white adipose tissue, has reached pandemic proportions and is recognized as an important health concern since it is a common root for several comorbidities, including malignancies. Indeed, the current knowledge of the white adipose tissue, which shifts its role from an energy storage tissue to an important endocrine and metabolic organ, has opened up new avenues for the discovery of obesity's effects on tumor biology. In this review, we will report the epidemiological studies concerning the strong impact of obesity in several types of cancer and describe the mechanisms underlying the heterotypic signals between cancer cell lines and adipocytes, with particular emphasis on inflammation, the insulin/IGF-1 axis, and adipokines. Among the adipokines, we will further describe the in vitro, in vivo, and clinical data concerning the role of leptin, recognized as one of the most important mediators of obesity-associated cancers. In fact, leptin physiologically regulates energy metabolism, appetite, and reproduction, and several studies have also described the role of leptin in affecting cancer development and progression. Finally, we will summarize the newest pharmacological strategies aimed at mitigating the protumorigenic effects of leptin, underlining their mechanisms of action.

Metabolic dysfunction and obesity-related cancer: Results from the cross-sectional National Health and Nutrition Examination Survey

BACKGROUND

Metabolic syndrome (MetS), a group of risk factors that define metabolic dysfunction in adults, is strongly associated with obesity and is an emerging risk factor for cancer. However, the association of MetS and degree of metabolic dysfunction with obesity-related cancer is unknown.

METHODS

Using National Health and Nutrition Examination Survey data from 1999 to 2018, we identified 528 obesity-related cancer cases and 18,972 cancer-free participants. MetS was defined as the presence of or treatment for ≥3 of hyperglycemia, hypertension, hypertriglyceridemia, low HDL-cholesterol, and abdominal obesity. A metabolic syndrome score (MSS) was computed as the total number of abnormal MetS parameters to determine the severity of metabolic dysfunction. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression models, adjusting for sociodemographic and lifestyle factors.

RESULTS

About 45.7% of obesity-related cancer cases were classified as having MetS compared with only 33.0% of cancer-free participants. Overall, MetS and MSS were not associated with obesity-related cancer. However, MSS was associated with higher obesity-related cancer risk among participants under 50 years of age (OR [95% CI] = 1.28 [1.08-1.52]). When evaluating MSS categorically, compared with healthy participants with no abnormal MetS parameters (MSS = 0), participants with one or two abnormal parameters had a statistically significant higher risk of obesity-related cancer (OR [95% CI] = 1.73 [1.06-2.83]).

CONCLUSIONS

Metabolic dysfunction is associated with a higher risk of obesity-related cancer, particularly in young adults under 50 years of age, and among participants with one or two abnormal metabolic parameters. A more accurate indicator of metabolic dysfunction, beyond metabolic syndrome, is needed to better assist in stratifying individuals for obesity-related cancer risk.

Insights behind the Relationship between Colorectal Cancer and Obesity: Is Visceral Adipose Tissue the Missing Link?

Colorectal cancer (CRC) is a major health problem worldwide, with an estimated 1.9 million new cases and 915,880 deaths in 2020 alone. The etiology of CRC is complex and involves both genetic and lifestyle factors. Obesity is a major risk factor for CRC, and the mechanisms underlying this link are still unclear. However, the generalized inflammatory state of adipose tissue in obesity is thought to play a role in the association between CRC risk and development. Visceral adipose tissue (VAT) is a major source of proinflammatory cytokines and other factors that contribute to the characteristic systemic low-grade inflammation associated with obesity. VAT is also closely associated with the tumor microenvironment (TME), and recent evidence suggests that adipocytes within the TME undergo phenotypic changes that contribute to tumor progression. In this review, we aim to summarize the current evidence linking obesity and CRC, with a focus on the role of VAT in tumor etiology and progression.

Synergism between the metabolic syndrome components and cancer incidence: results from a prospective nested case-control study based on the China Health and Retirement Longitudinal Study (CHARLS)

OBJECTIVES

Synergism between the metabolic syndrome (MetSyn) components and cancer incidence still remains inconclusive. We aimed to investigate the unique or joint role of MetSyn components in cancer onset.

DESIGN

We conducted a prospective nested case-control study based on the China Health and Retirement Longitudinal Study.

SETTING

An ongoing national representative longitudinal study included follow-up survey of people aged 45 years and older and their partners living in private households in China.

PARTICIPANTS

There were 17 708 individuals included at baseline. A total of 306 incident cancers was identified during the follow-up. For every case, we used incidence-density sampling to match three concurrent cancer-free controls by age, sex, and both duration and calendar time of follow-up. Exposure of interest was any MetSyn diagnosis at baseline.

RESULTS

We observed elevation in cancer risk associated with MetSyn in a significant way when the number of MetSyn components was over three (OR: 1.88; 95% CI: 1.19 to 2.97), or when components contained any of elevated triglycerides (OR: 1.61; 95% CI: 1.05 to 2.48), reduced high-density lipoprotein (HDL) cholesterol (OR: 2.33; 95% CI: 1.40 to 3.86) or elevated blood pressure (OR: 1.65; 95% CI: 1.04 to 2.59) after consistent multiple adjustments in different models. The highest cancer risk was in the female reproductive system and breast cancer (OR: 4.22; 95% CI: 1.62 to 10.95) followed by digestive system (OR: 1.67; 95% CI: 1.11 to 2.53). Sensitivity analyses showed similar results after first follow-up was excluded. However, any unique MetSyn component was not associated with increased cancer risk. Interestingly, the reduced HDL was observed to be widely associated with over twofold increased risk of cancer, only when together with other MetSyn components.

CONCLUSION

MetSyn components, in a collaborative manner rather than its unique component, were associated with elevated cancer risk. Not only obesity but even subtle metabolic disturbances may give rise to cancer.

Association Between Metabolic Syndrome and the Risk of Colorectal Cancer Diagnosed Before Age 50 Years According to Tumor Location

BACKGROUND & AIMS

The increasing prevalence of obesity at younger ages is concurrent with an increased earlier-onset colorectal cancer (CRC) (before age 50 years) incidence, particularly left-sided colon cancer. We investigated whether obesity and metabolic syndrome (MetS) are associated with increased earlier-onset CRC risk according to tumor location.

METHODS

Our nationwide population-based cohort study enrolled 9,774,081 individuals who underwent health checkups under the Korean National Health Insurance Service from 2009 to 2010, with follow-up until 2019. We collected data on age, sex, lifestyle factors, body mass index (BMI), waist circumference (WC), blood pressure, and laboratory findings. A multivariate Cox proportional hazards regression analysis was performed.

RESULTS

A total of 8320 earlier-onset and 57,257 later-onset CRC cases developed during follow-up. MetS was associated with increased earlier-onset CRC (adjusted hazard ratio, 1.20; 95% CI, 1.14-1.27), similar to later-onset CRC (adjusted hazard ratio, 1.19; 95% CI, 1.17-1.21). The adjusted hazard ratios for earlier-onset CRC with 1, 2, 3, 4, and 5 MetS components were 1.07 (95% CI, 1.01-1.13), 1.13 (95% CI, 1.06-1.21), 1.25 (95% CI, 1.16-1.35), 1.27 (95% CI, 1.15-1.41), and 1.50 (95% CI, 1.26-1.79), respectively (P for trend < .0001). We found that higher body mass index and larger waist circumference were significantly associated with increased earlier-onset CRC (P for trend < .0001). These dose-response associations were significant in distal colon and rectal cancers, although not in proximal colon cancers.

CONCLUSIONS

MetS and obesity are positively associated with CRC before age 50 years with a similar magnitude of association as people diagnosed after age 50 years. Thus, people younger than 50 years with MetS require effective preventive interventions to help reduce CRC risk.

Association between oral cavity cancer and metabolic syndrome

PURPOSE

Few studies have been conducted on the association between oral cavity cancer and metabolic diseases. This study aimed to investigate the relationship between oral cavity cancer and metabolic diseases.

METHODS

This cohort study used the database of the Korean National Health Insurance Service, which contains medical data of 97% of the Korean population. Oral cavity cancer occurred in a total of 2718 patients. Metabolic syndrome was defined according to IDF criteria. The Cox proportional hazard regression model was used.

RESULTS

The HR for oral cavity cancer in patients with metabolic syndrome was 1.113(95% CI 1.006-1.232), which was significantly higher than that in normal patients, especially in males (p = 0.0386). When the number of metabolic syndrome factors was ≥ 3, the HR of oral cavity cancer was 1.191(95% CI 1.026-1.383), which was significantly higher than that of 0 metabolic syndrome factors, especially in males (p = 0.0218). When the number of metabolic syndrome factors was ≥ 3, the HR for oral cavity cancer was 1.439(95% CI 1.066-1.942), which was significantly higher than that of 0 metabolic syndrome factors, especially in males aged < 50 years (p = 0.0173).

CONCLUSION

Metabolic syndrome increases the risk of oral cavity cancer only in males. In addition, the incidence of oral cavity cancer increased as the number of factors constituting metabolic syndrome increased, only in young males aged < 50 years. Thus, metabolic syndrome is an important risk factor for oral cavity cancer, particularly in young males.

Metabolic dysfunction and obesity-related cancer: Beyond obesity and metabolic syndrome

OBJECTIVES

The metabolic dysfunction driven by obesity, including hyperglycemia and dyslipidemia, increases risk for developing at least 13 cancer types. The concept of "metabolic dysfunction" is often defined by meeting various combinations of criteria for metabolic syndrome. However, the lack of a unified definition of metabolic dysfunction makes it difficult to compare findings across studies. This review summarizes 129 studies that evaluated variable definitions of metabolic dysfunction in relation to obesity-related cancer risk and mortality after a cancer diagnosis. Strategies for metabolic dysfunction management are also discussed.

METHODS

A comprehensive search of relevant publications in MEDLINE (PubMed) and Google Scholar with review of references was conducted.

RESULTS

Metabolic dysfunction, defined as metabolic syndrome diagnosis or any number of metabolic syndrome criteria out of clinical range, inflammatory biomarkers, or markers of metabolic organ function, has been associated with risk for, and mortality from, colorectal, pancreatic, postmenopausal breast, and bladder cancers. Metabolic dysfunction associations with breast and colorectal cancer risk have been observed independently of BMI, with increased risk in individuals with metabolically unhealthy normal weight or overweight/obesity compared with metabolically healthy normal weight.

CONCLUSION

Metabolic dysfunction is a key risk factor for obesity-related cancer, regardless of obesity status. Nonetheless, a harmonized definition of metabolic dysfunction will further clarify the magnitude of the relationship across cancer types, enable better comparisons across studies, and further guide criteria for obesity-related cancer risk stratification.

Metabolic Syndrome as a Risk Factor of Endometrial Cancer: A Nationwide Population-Based Cohort Study of 2.8 Million Women in South Korea

Background

A positive relationship was reported between metabolic syndrome and the risk of endometrial cancer. Studies on the relationship between metabolic syndrome and endometrial cancer have been mainly conducted in post-menopausal women. We aimed to investigate the risk of endometrial cancer according to metabolic syndrome and menopausal status using the Korean nationwide population-based cohort.

Methods

We enrolled 2,824,107 adults (endometrial cancer group; N = 5,604 and control group; N= 2,818,503) from the Korean National Health Insurance Service checkup database from January 1 to December 31, 2009. The median follow-up duration was 8.37 years. Metabolic syndrome was diagnosed as having at least three of the following five components: abdominal obesity, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, raised blood pressure, and hyperglycemia. Multivariate Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to estimate endometrial cancer risk.

Results

The endometrial cancer risk was higher in the metabolic syndrome group than that in the non-metabolic syndrome group (HR, 1.362; 95% CI, 1.281–1.449). The association between metabolic syndrome and endometrial cancer risk was significant in the premenopausal subgroup (HR, 1.543; 95% CI, 1.39–1.713) and postmenopausal subgroup (HR, 1.306; 95% CI, 1.213–1.407). The incidence of endometrial cancer was more closely related to metabolic syndrome components in the pre-menopausal subgroup than those in the post-menopausal subgroup (for waist circumference, blood pressure, triglycerides and high-density lipoprotein cholesterol, all p for interaction <0.0001 respectively, and for fasting blood glucose, p for interaction 0.0188). The incidence of endometrial cancer positively correlated with the number of metabolic syndrome components (log-rank p <0.0001).

Conclusion

Our large population-based cohort study in Korean women suggests that metabolic syndrome and its accumulated components may be risk factors for endometrial cancer, particularly in the pre-menopausal women.

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.

Metabolic syndrome and the risk of colorectal cancer: a systematic review and meta-analysis

PURPOSE

Observational studies have reported an association between metabolic syndrome (MetS) and colorectal cancer risk with inconsistent risk estimates. We conducted this meta-analysis to evaluate the risk of colorectal cancer in individuals with MetS.

METHODS

PubMed, Embase, and Web of Science were searched for related studies from database inception to 21 January 2021. Risk estimates for colorectal cancer were extracted from individual articles and pooled using a fixed-effect or random-effect model according to the heterogeneity.

RESULTS

MetS was significantly associated with a higher risk of colorectal cancer in both sexes (relative risk [RR] 1.36, 95% confidence interval [CI] 1.26-1.47, P < 0.001), men (RR 1.33, 95% CI 1.21-1.47, P < 0.001), and women (RR 1.34, 95% CI 1.19-1.52, P < 0.001). The risk of colorectal cancer seemed to increase as the number of MetS components rose. Moreover, the high body mass index (BMI)/waist circumference (WC) and hyperglycemia were all significantly associated with a higher risk of colorectal cancer (RR 1.28 [1.20-1.37] and 1.31 [1.14-1.50] in both sexes, RR 1.31 [1.19-1.45] and 1.23 [1.03-1.46] in men, and RR 1.22 [1.02-1.46] and 1.63 [1.16-2.28] in women, respectively).

CONCLUSIONS

MetS was significantly associated with a higher risk of colorectal cancer. The high BMI/WC or hyperglycemia might largely account for this association. Further analysis suggested that, as the number of MetS components increased, the risk of colorectal cancer rose.

Visceral Adiposity Index is a predictor of incident colorectal cancer: a population-based longitudinal study

Objective

The Visceral Adiposity Index (VAI) is a marker of visceral fat accumulation and dysfunction. We aimed to investigate the association between VAI and incident colorectal cancer (CRC).

Design

In this historical cohort study of 27 921 (16 434 men and 11 487 women) participants, we divided the participants into tertiles according to VAI. We calculated VAI: men, VAI = (waist circumference (WC)/(39.68+1.88 × body mass index (BMI))) × (triglycerides (TG)/1.03) × (1.31/high-density lipoprotein cholesterol (HDL)); women, VAI = (WC/(36.58+1.89 × BMI)) × (TG/0.81) × (1.52/HDL). We performed Cox proportional hazard models, adjusting for sex, age, smoking, alcohol consumption, exercise, haemoglobin A1c and systolic blood pressure.

Results

During the median 4.4-year follow-up, 116 participants developed CRC. Compared with the lowest tertile, the HRs of incident CRC in the middle and the highest tertiles were 1.30 (95% CI 0.76 to 2.28, p=0.338) and 2.41 (1.50 to 4.02, p<0.001) in univariate analysis. Moreover, the HRs of incident CRC in the middle and the highest tertiles were 1.27 (0.73 to 2.23, p=0.396) and 1.98 (1.15 to 3.39, p=0.013) after adjusting for covariates.

Conclusions

VAI can be a predictor of incident CRC. For early detection, we should encourage people with high VAI to undergo screening for CRC.

Influence of chronic comorbidities on periodic colorectal cancer screening participation: A population-based cohort study

Guidelines recommend regular screening for colorectal cancer (CRC). We examined the effects of chronic comorbidities on periodic CRC testing. Using linked healthcare databases from Ontario, Canada, we assembled a population-based cohort of 50-74-year olds overdue for guideline-recommended CRC screening between April 1, 2004 and March 31, 2016. We implemented multivariable recurrent events models to determine the association between comorbidities and the rate of becoming up-to-date with periodic CRC tests. The cohort included 4,642,422 individuals. CRC testing rates were significantly lower in persons with renal disease on dialysis (hazard ratio, HR 0.66, 95% confidence interval, CI 0.63 to 0.68), heart failure (HR 0.75, CI 0.75 to 0.76), respiratory disease (HR 0.84, CI 0.83 to 0.84), cardiovascular disease (HR 0.85, CI 0.84 to 0.85), diabetes (HR 0.86, 95% CI 0.86 to 0.87) and mental illness (HR 0.88, CI 0.87 to 0.88). There was an inverse association between the number of medical conditions and the rate of CRC testing (5 vs. none: HR 0.30, CI 0.25 to 0.36; 4 vs. none: HR 0.48, CI 0.47 to 0.50; 3 vs. none: HR 0.59, CI 0.58 to 0.60; 2 vs. none: HR 0.72, CI 0.71 to 0.72; 1 vs. none: HR 0.85, CI 0.84 to 0.85). Having both medical and mental comorbidities was associated with lower testing rates than either type of comorbidity alone (HR 0.72, CI 0.71 to 0.72). In summary, chronic comorbidities present a barrier to periodic guideline-recommended CRC testing. Exploration of cancer prevention gaps in these populations is warranted.

Association of circulating leptin and adiponectin levels with colorectal cancer risk: A systematic review and meta-analysis of case-control studies

PURPOSE

Leptin and adiponectin are adipokines which have been commonly implicated in carcinogenesis. As such, many studies have investigated the association of circulating leptin and adiponectin levels with colorectal cancer (CRC) risk. However, the results remained inconsistent.

METHODS

In this work, we performed a systematic review and meta-analysis to precisely examine the association between circulating levels of leptin and adiponectin and CRC risk. A systematic literature search was performed in PubMed/MEDLINE, Scopus, Web of Science, and EMBASE databases from inception until October 2020. The pooled effect size was then estimated by calculating the odds ratio (OR).

RESULTS

A total of 23 records (comprising 26 studies) were included in the meta-analysis. The overall analysis found that circulating levels of leptin and adiponectin were not significantly associated with CRC risk (P > 0.05). Interestingly, subgroup analysis revealed that a higher level of adiponectin was significantly associated with an increased CRC risk among overweight individuals (OR = 1.16; 95 % CI: 1.02, 1.32), and a decreased CRC risk among normal weight individuals (OR = 0.76; 95 % CI: 0.62, 0.92). Besides, a higher level of adiponectin was also significantly associated with a decreased risk of CRC in men (OR = 0.76; 95 % CI: 0.59, 0.98).

CONCLUSIONS

In conclusion, circulating leptin level was not associated with CRC risk, but that of adiponectin was associated with CRC risk only in specific subgroups.

Early age onset colorectal cancer

The incidence and mortality associated with colorectal cancer (CRC) diagnosed in patients under the age of 50 have been steadily increasing. The exact etiology of these epidemiologic trends is unclear. This chapter will provide a comprehensive review on the topic of early age onset colorectal cancer (EAO-CRC), defined as colorectal cancer (CRC) diagnosed in patients under the age of 50. Topics reviewed will include the epidemiology of EAO-CRC around the world, clinical and pathological features of EAO-CRC in contrast to later age onset CRC (CRC diagnosed on those over the age of 50) and the observed molecular and somatic characteristics. This chapter will review the etiologies to EAO-CRC and the established, as well as proposed risk factors for disease. Evidence-based approaches to prevention, early detection, treatment and survivorship will be presented.

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.

The association of Metabolic Syndrome and its Components with the Incidence and Survival of Colorectal Cancer: A Systematic Review and Meta-analysis

Background: This meta-analysis was aimed to quantitatively assess the associations of metabolic syndrome (MetS) and its components with colorectal cancer (CRC). Methods: PubMed, EMBASE and Web of Science databases were systematically searched for eligible studies. A total of 18 studies for CRC incidence and 12 studies for CRC mortality were identified. Results: MetS was associated with an increased risk of CRC incidence and mortality in male (RR: 1.28, 95 % CI 1.16-1.39, and 1.24, 1.18-1.31, respectively) and correlated with an increased risk of CRC incidence in female (RR: 1.21, 1.13-1.30), but not with CRC mortality in female. MetS increased the risk of cancer-specific mortality (RR: 1.72, 1.03-2.42), but not overall mortality. The risk estimates of CRC incidence changed little depending on age, sex, cancer site, the type of studies, ethnicity, publication year, or definition of MetS. As for CRC mortality, further stratified analyses indicated statistical significance in studies with assessing cancer-specific survival outcome, in male, a cohort design, ethnicity of non-Chinese or with definition of MetS as ≥ 3 metabolic abnormalities. Obesity and hyperglycemia are risk factors of CRC incidence in both male and female. Only dysglycemia is the risk factor for CRC mortality. Conclusions: MetS is associated with an increased risk of CRC incidence and cancer-specific mortality, but not overall mortality. In addition, MetS may increase the CRC mortality in male rather than in female. However, since most of the studies on CRC mortality were conducted in Chinese, further studies are needed to clarify this connection.

Triglyceride-glucose index (TyG index) is a predictor of incident colorectal cancer: a population-based longitudinal study

BACKGROUND

Colorectal cancer (CRC), which is related with insulin resistance, is a one of the most common cancers. Triglyceride-glucose index (TyG index) was made for a marker of insulin resistance. We conducted the investigation of association between TyG index and incident CRC.

METHODS

We examined the affect of TyG index on incident CRC in this historical cohort study of 27,944 (16,454 men and 11,490 women) participants. TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. The impact of TyG index on incident CRC was investigated using Cox proportional hazard models, adjusting for sex, age, body mass index, smoking status, alcohol consumption, exercise, systolic blood pressure and creatinine. The covariate-adjusted receiver operating characteristic (ROC) curve calculated the area under the curve (AUC) and cut-off value of TyG index for the incidence of CRC.

RESULTS

During the median 4.4-year follow-up, 116 participants were diagnosed as CRC. The cumulative incidence rate of CRC were 0.4%. In Cox proportional hazard model, the HRs of TyG index were 1.38 (95% Confidence interval (CI), 1.00-1.91, p = 0.049) after adjusting for covariates. In the covariate-adjusted ROC curve analysis, the cut-off value of TyG index for incident CRC was 8.272 (AUC 0.687 (95%CI, 0.637-737, sensitivity = 0.620, specificity = 0.668, p < 0.001)).

CONCLUSIONS

TyG index can predict the onset of CRC. For early detection of CRC, we should encourage people with high TyG index to undergo screening for CRC.

Investigation of the Risk Factors and Associated Co-Morbid Conditions among Patients with Colorectal Cancer in Trinidad

Colorectal cancer (CRC) is the third most common cancer, and the fourth most common cause of cancer mortality worldwide. In Trinidad and Tobago, it is the third most common type of cancer in both sexes. Since there is scanty research on the risk factors associated with CRC, this study was conducted to determine the correlation between risk factors, including associated comorbid conditions, and CRC in Trinidad. A cross-sectional study was conducted amongst diagnosed CRC patients (>18 years) using a pre-tested questionnaire consisting of sections on demographic data, lifestyle before diagnosis, quality of life, and depression status. Additional information such as recurrence of cancer, Body Mass Index (BMI), Hypertension (HT), blood glucose levels and family history of cancer were collected from the medical records. Of the total participants, the majority were males (58%), and the mean age of diagnosis in both sexes was 65 years. The retrospective chart review showed that 68% were found to have a comorbid condition (Diabetes or HT). Upon review of the medical records, 93.2% of the subjects did not have a familial history. However, the questionnaire data showed that 73% of subjects had a family history. Around 50% of CRC patients were alcohol consumers and 30% were cigarette smokers prior to their cancer diagnosis. Interestingly, a majority of patients (91%) had never been screened for CRC prior to their diagnosis. Subjects with CRC displayed minimal depression, indicating that being diagnosed with CRC did not have a grave impact on their state of mind or quality of life. Our findings showed that prevalence of CRC was higher in males and amongst individuals of African descent. However, larger prospective studies may be warranted to fully demonstrate this effect.

The relationship between metabolic syndrome and the incidence of colorectal cancer

OBJECTIVES

This study evaluated the incidence of colorectal cancer (CRC) according to the number of metabolic syndrome (MetS) components.

METHODS

Using health checkup and insurance claims data of 6,365,409 subjects, the occurrence of CRC according to stage of MetS by sex was determined from the date of the health checkup in 2009 until December 31, 2018.

RESULTS

Cumulative incidence rates (CIR) of CRC in men and women was 3.9 and 2.8 per 1000 (p < 0.001), respectively. CIR of CRC for the normal, pre-MetS, and MetS groups in men was 2.6, 3.9, and 5.5 per 1000 (p < 0.001) and CIR in women was 2.1, 2.9, and 4.5 per 1000 (p < 0.001), respectively. Compared with the normal group, the hazard ratio (HR) of CRC for the pre-MetS group was 1.25 (95% CI 1.17-1.33) in men and 1.09 (95% CI 1.02-1.17) in women, and the HR of CRC for the MetS group was 1.54 (95% CI 1.43-1.65) in men and 1.39 (95% CI 1.26-1.53) in women after adjustment.

CONCLUSIONS

We found that MetS is a risk factor for CRC in this study. Therefore, the prevention and active management of MetS would contribute to the prevention of CRC.

Mendelian randomisation: A powerful and inexpensive method for identifying and excluding non-genetic risk factors for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in economically developed countries and a major cause of cancer-related mortality. The importance of lifestyle and diet as major determinants of CRC risk is suggested by differences in CRC incidence between countries and in migration studies. Previous observational epidemiological studies have identified associations between modifiable environmental risk factors and CRC, but these studies can be susceptible to reverse causation and confounding, and their results can therefore conflict. Mendelian randomisation (MR) analysis represents an approach complementary to conventional observational studies examining associations between exposures and disease. The MR strategy employs allelic variants as instrumental variables (IVs), which act as proxies for non-genetic exposures. These allelic variants are randomly assigned during meiosis and can therefore inform on life-long exposure, whilst not being subject to reverse causation. In previous studies MR frameworks have associated several modifiable factors with CRC risk, including adiposity, hyperlipidaemia, fatty acid profile and alcohol consumption. In this review we detail the use of MR to investigate and discover CRC risk factors, and its future applications.

Metabolic syndrome and risk of cancer: a study protocol of case-control study using data from the Information System for the Development of Research in Primary Care (SIDIAP) in Catalonia

BACKGROUND

Metabolic syndrome (MS) is defined by the clustering of specific metabolic disorders in one subject. MS is highly prevalent globally and currently considered a growing public health concern. MS comprises obesity, hypertension, dyslipidaemia and insulin resistance. Mechanisms linking MS with cancer are poorly understood, and it is as yet unknown if MS confers a greater risk than the risk entailed by each of its separate components. The main objective of this study is to compare the association between MS and 14 site-specific cancer against the association between one or two individual components of MS and cancer. The secondary objective is to evaluate the time elapsed since the diagnosis of MS and the subsequent onset of cancer within the 2006-2017 period by sex.

METHODS AND ANALYSIS

A case-control study will be conducted for the main objective and a cohort of patients with MS will be followed for the evaluation of the second objective. Incident cases of fourteen types of cancer in patients ≥40 years of age diagnosed prospectively will be selected from electronic primary care records in the Information System for Research in Primary Care (SIDIAP database; www.sidiap.org). The SIDIAP database includes anonymous data from 6 million people (80% of the Catalan population) registered in 286 primary healthcare centres. Each matched control (four controls for each case) will have the same inclusion date, the same sex and age (±1 year) than the paired case. Logistic regression and a descriptive analysis and Kaplan-Meier analysis will be performed, in accordance with the objectives.

ETHICS AND DISSEMINATION

The protocol of the study was approved by the IDIAP Jordi Gol Clinical Research Ethics Committee (protocol P17/212). The study's findings will be published in a peer-reviewed journal and disseminated at national and international conferences and oral presentations to researchers, clinicians and policy makers.

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.

Metabolic Syndrome in Endometrial Cancer Patients: Systematic Review

Large numbers of previously published studies show the importance of Metabolic syndrome (MetS) in the development of endometrial cancer (EC), the most common gynecologic malignancy in the United States. Defining the association between EC and MetS is complicated by inconsistencies among the MetS definitions used in EC. The aim of this study was to identify the MetS definition that is most practical for EC patients, as well as to estimate the prevalence of MetS using each definition in EC patients. A systematic literature search of PubMed and Embase was conducted to identify studies published between 1988 and 2018 and reporting the components of MetS in EC patients. Relevant studies were selected based on the presence of key MetS components, including central obesity, dyslipidemia, elevated blood pressure, and impaired glucose metabolism. Two independent reviewers extracted information from these articles. Our literature search has identified 400 articles, 8 of which were used for the final analyses. In this systematic review, the prevalence of MetS in EC patients varied based on the definition used, ranging from 6% for International Diabetes Federation (IDF) to 62% for Harmonized. IDF and Harmonized of MetS were the most practical definitions for women with EC. While our review included different approaches to diagnosing MetS and linking it to EC, we argue that there is a need for single and practical MetS definition criteria to improve diagnostics, decrease the inconsistencies across the future EC studies, and foster a cohesive understanding of the evidence regarding the association between MetS and EC.

A Comparative Study Evaluating the Incidence of Colorectal Neoplasia(s) in Candidates for Bariatric Surgery by Screening Colonoscopy, 40-49 Versus 50-65 Years Old: a Preliminary Study

INTRODUCTION

Obesity and metabolic syndrome (MetS) are associated with colorectal neoplasia (CRN) and carcinoma (CRC). Whether such subjects must undergo screening colonoscopy (SC) earlier, is unknown. Incidences of CRNs in 40-49- versus 50-65-year-old bariatric patients were compared by SC. No prospective data on SC is available in morbidly obese/MetS.

MATERIAL AND METHODS

Surgical weight loss candidates over 39 years of age, asymptomatic, and average-risk for CRC offered SC. Those giving written informed consent were enrolled. Colonoscopies were done by the same surgeon. Smoking/drinking history, fasting blood glucose (FBG), insulin, C-peptide, triglyceride, high density lipoprotein, vitamin D, HbA1c, and insulin resistance parameters were recorded. CRN rate and the distribution of variables in patients 40-49 years of age were compared with 50-65. Student's t and Chi-square tests were used as appropriate. P < 0.05 was regarded as statistically significant.

RESULTS

Among 168 SCs, 47 had CRNs (27.9%). Including carcinoma, 15 had an advanced CRN (aCRN) (8.9% aCRN and 0.6% CRC). CRN rate was 35.6% in ≥ 50 years old whereas 22.1% in 40-49 (p = 0.053). aCRN rates (8.4% in 40-49 versus 9.6% in 50-65) were similar (p = 0.792). Metabolic parameters and smoking-drinking history were equally distributed between the groups except FBG and HbA1c as their mean levels were slightly higher in the 50-65 age group (p < 0.05).

CONCLUSIONS

Presented results warrant routine SC in the 40-49-year-old morbidly obese and/or MetS patient population with average risk, and in aged > 50, it certainly must be enforced and included in the preoperative check-list if not done before.

Plasma C-peptide and glycated albumin and subsequent risk of cancer: From a large prospective case-cohort study in Japan

To elucidate the individual impacts of insulin and blood glucose on cancer risk, we investigated the association of plasma C-peptide, a surrogated marker of insulin and glycated albumin (GA), a more stable marker of blood glucose, with all-site and site-specific cancer risk by mutually accounting for their confounding effects. The study was prospectively conducted with nearly 4,000 cancer cases arising in our population-based cohort of 33,736 subjects who answered the baseline questionnaire and supplied blood samples. After exclusion of subjects with apparent DM, analysis was done in 3,036 cancer cases and 3,667 subcohort subjects. Among men and women combined, highest levels of C-peptide were statistically significantly associated with an increased risk of all-site [Hazard ratio (HR): 1.21; 95% confidence interval: 1.02-1.42], colon [1.73; 1.20-2.47], liver [3.23; 1.76-5.91], kidney, renal pelvis and ureter cancers [2.47; 1.07-5.69], compared to the respective lowest levels, after adjustment for GA levels. Among these C-peptide-related cancers, colon and liver cancers also showed an increased risk associated with elevated GA levels independently of C-peptide levels. The corresponding HRs for colon and liver cancers compared to the highest and lowest GA levels were 1.43 [1.02-2.00] and 2.02 [1.15-3.55], respectively. Effect modification by gender was only evident for the association between C-peptide and colon cancer (p for interaction = 0.04). Higher insulin levels, independently of higher blood glucose levels, may be relevant to DM-related carcinogenesis for several cancer sites. Examination of circulating insulin levels is a plausible option in evaluating cancer risk even in individuals who have not developed DM.

Metabolic syndrome is a risk factor for colorectal adenoma and cancer: a study in a White population using the harmonized criteria

BACKGROUND

Metabolic syndrome (MetS) has been associated with colorectal adenomas and cancer. However, MetS definitions have changed over time, leading to a heterogeneity of patients included in previous studies and a substantial inextensibility of observations across time or eastern and western populations. Our aim was to evaluate the association of 'harmonized' criteria-defined MetS and its individual components with colorectal neoplasia and cancer in a western population.

METHODS

In this multicenter, cross-sectional study, we prospectively evaluated consecutive outpatients who underwent open-access colonoscopy over a 3-month period. MetS was diagnosed according to the 2009 'harmonized' criteria.

RESULTS

Out of 5707 patients enrolled, we found 213 cancers (3.7%), 1614 polyps (28.3%), 240 nonpolypoid lesions (4.2%), 95 laterally spreading tumors (1.6%). Polyps presented histological low-grade dysplasia in 72.9% of samples, while in 9.8%, high-grade dysplasia or in situ carcinoma was present; dysplasia rates for nonpolypoid lesions were 66.2% (low-grade) and 2.9% (high-grade/in situ carcinoma), while for laterally spreading tumors, 29.6% and 37%, respectively. Overall, MetS prevalence was 41.6%. MetS correlated with both adenomas [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.54-2.00] and cancer (OR: 1.92, 95% CI 1.42-2.58). MetS was the only risk factor for such colonic lesions in subjects younger than 50 years. For all colonic neoplasia, we found MetS and not its individual components to be significantly associated.

CONCLUSIONS

MetS is risk factor for cancer and adenoma in Whites, especially when younger than 50 years. MetS patients might be considered as a high-risk population also in colorectal cancer screening programs.

Abdominal obesity, glucose intolerance and decreased high-density lipoprotein cholesterol as components of the metabolic syndrome are associated with the development of colorectal cancer

Metabolic syndrome (MetS) and its components has been thought to be involved in the development of colorectal cancer (CRC). However, the results is often inconsistent according to gender or anatomical location of tumor. This study aimed to investigate the association between MetS and its components and CRC development by gender and tumor location. We evaluated the data of 22,809,722 Korean individuals of the National semi-compulsive cohort who underwent regular health check-ups between 2009 and 2012. Compared to subjects without MetS components, the hazard ratio for CRC development in patients with MetS was 1.22 (95% Confidence Interval [CI] 1.20-1.24) and this association was more prominent in men than in women (HR 1.41 95% CI 1.37-1.44 vs. HR 1.23 95% CI 1.20-1.27, P for interaction < 0.001). Left-sided colon cancers were more associated with MetS among men compared to women (HR 1.70, 95% CI 1.61-1.80 vs. HR 1.43, 95% CI 1.33-1.54), while right colon cancers showed a stronger association with MetS among women than men (HR 1.63, 95% CI 1.49-1.78 vs. HR 1.34, 95% CI 1.24-1.44) (all P for interaction < 0.001, respectively). Having two MetS components was still associated with CRC development and the association was the highest when two of glucose intolerance, abdominal obesity and low high-density lipoprotein cholesterol (HDL-C) combined. Individuals with glucose intolerance, abdominal obesity or low HDL-C levels, may need to undergo thorough screening for CRC even if they do not meet the diagnostic MetS criteria.

The combined effect of non-alcoholic fatty liver disease and metabolic syndrome on colorectal carcinoma mortality: a retrospective in Chinese females

BACKGROUND

This research aimed to investigate whether metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) had both individual and synergistic effects on the prognosis for female colorectal carcinoma (CRC) patients.

METHODS

The relationship between CRC prognosis and NAFLD as well as MetS was evaluated in 764 female participants. Based on the NAFLD level, patients were divided into significant NAFLD (SNAFLD), "moderate" and "severe" level, and non-SNAFLD, "non" and "mild" level. All the patients were categorized into four subgroups according to the status of SNAFLD and MetS and then a comparison of CRC prognosis among those four groups was performed.

RESULTS

NAFLD, SNAFLD, and MetS were independent factors for CRC-specific mortality with the adjustment of age and other confounders. The hazard ratio (HR) of CRC-specific mortality in MetS (+) SNAFLD (+) group was significantly higher than that in other three groups. Relative excess risk of interaction (RERI) was 2.203 with 95% CI ranged from 0.197 to 4.210, attributable proportion (AP) was 0.444 with range from 0.222 to 0.667, and synergy index (SI) of 2.256 with 95% CI from 1.252 to 4.065, indicating SNAFLD and MetS had a significant synergic effect on CRC-specific mortality.

CONCLUSIONS

SNAFLD and MetS are independent risk factors for CRC-specific mortality in females. Moreover, those two diseases have a synergistic effect on promoting CRC-specific mortality.

Low circulating total adiponectin, especially its non-high-molecular weight fraction, represents a promising risk factor for colorectal cancer: a meta-analysis

Aim

The principal goal of this meta-analysis is to test the hypothesis that circulating total adiponectin or certain fractions may represent a promising biological candidate in modulating the risk of colorectal cancer.

Methods

The processes of paper identification, paper selection and data extraction were accomplished independently by two authors. Effect-size estimates were expressed as weighted mean difference (WMD) and 95% confidence interval (95% CI). A total of 31 papers including 48 qualified studies (7,554 patients with colorectal cancer and 9,798 controls) were meta-analyzed.

Results

Pooling all studies found that circulating total adiponectin was significantly lower in patients with colorectal cancer than in controls (WMD: −0.76 µg/mL, 95% CI: −1.20 to −0.32, p=0.001), with significant heterogeneity (I²: 94.2%) and low publication bias (Egger’s p=0.336). By adiponectin fractions, the difference in high-molecular weight (HMW) adiponectin was comparable between the two groups (WMD: −0.22 µg/mL, 95% CI: −0.70 to 0.25, p=0.350), while non-HMW adiponectin was significantly lower in patients with colorectal cancer than in controls (WMD: −0.27 µg/mL, 95% CI: −0.35 to −0.19, p<0.001), with marginal heterogeneity (I²: 52.3%). Subgroup analysis revealed that effect-size estimates were heterogeneous when grouping studies by cancer subtype, region, study design, matching status, gender and obesity. Further meta-regression analysis indicated that age and gender were significant potential sources of heterogeneity. The results showed the studied subgroups were not subject to publication bias (Egger’s p<0.1).

Conclusion

Our data collectively indicate that low circulating total adiponectin, especially its non-HMW fraction, represents a promising risk factor for colorectal cancer. Further studies are needed to explore underlying mechanisms.

Circulating adiponectin levels in various malignancies: an updated meta-analysis of 107 studies

Early detection of cancers is challenging for lack of specific biomarkers. Adiponectin is an adipokine predominantly derived from adipocytes and hypoadiponectinemia has been reported to associate with risk of many types of cancers. However, available evidence is controversial. Some studies show that increased adiponectin levels correlate with cancer risk. Therefore, we performed a meta-analysis of the association between circulating adiponectin levels and cancer development. A systematic search of PubMed, EMBASE, Wiley Online Library and Cochrane Library was conducted for eligible studies involving circulating adiponectin and malignancies from inception to August 8, 2015. Standard mean differences (SMDs) with 95% confidence intervals (95% CIs) were calculated by use of a random-effect model. Funnel plot and Egger's linear regression test were conducted to examine the risk of publication bias. 107 studies were included with 19,319 cases and 25,675 controls. The pooled analysis indicated that circulating adiponectin levels were lower in patients with various cancers than in controls, with a pooled SMD of −0.334 μg/ml (95% CI, −0.465 to −0.203, P = 0.000). No evidence of publication bias was observed. Circulating high molecular weight adiponectin levels were also lower in cancer patients than in controls, with a pooled SMD of −0.502 μg/ml (95% CI, −0.957 to −0.047, P = 0.000). This meta-analysis provides further evidence that decreased adiponectin levels is associated with risk of various cancers. Hypoadiponectinemia may represent a useful biomarker for early detection of cancers.

Adiponectin, Leptin, IGF-1, and Tumor Necrosis Factor Alpha As Potential Serum Biomarkers for Non-Invasive Diagnosis of Colorectal Adenoma in African Americans

The potential role of adiponectin, leptin, IGF-1, and tumor necrosis factor alpha (TNF-α) as biomarkers in colorectal adenoma is not clear. Therefore, we aimed to investigate the blood serum levels of these biomarkers in colorectal adenoma. The case-control study consisted of serum from 180 African American patients with colon adenoma (cases) and 198 healthy African Americans (controls) at Howard University Hospital. We used ELISA for adiponectin, leptin, IGF-1, and TNF-α detection and quantification. Statistical analysis was performed by t-test and multivariate logistic regression. The respective differences in median leptin, adiponectin, IGF-1, and TNF-α levels between control and case groups (13.9 vs. 16.4), (11.3 vs. 46.0), (4.5 vs. 12.9), and (71.4 vs. 130.8) were statistically significant (P < 0.05). In a multivariate model, the odds ratio for adiponectin, TNF-α, and IGF-1 were 2.0 (95% CI = 1.6-2.5; P < 0.001), 1.5 (95% CI = 1.5(1.1-2.0); P = 0.004), and 1.6 (95% CI = 1.3-2.0; P < 0.001), respectively. There was a positive correlation between serum adiponectin and IGF-1 concentrations with age (r = 0.17, P < 0.001 and r = 0.13, P = 0.009), TNF-α, IGF-1, and leptin concentration with body mass index (BMI) (r = 0.44, P < 0.001; r = 0.11, P = 0.03; and r = 0.48, P < 0.001), respectively. Also, there was a negative correlation between adiponectin and leptin concentrations with BMI (r = -0.40, P < 0.001), respectively. These data support the hypothesis that adiponectin, IGF-1, and TNF-α high levels correlate with higher risk of colon adenoma and can thus be used for colorectal adenomas risk assessment.

Breast Cancer Epidemiology, Prevention, and Screening

Globally, breast cancer is both the most commonly occurring cancer and the commonest cause of cancer death among women. Available data suggest that incidence and mortality in high-resource countries has been declining whereas incidence and mortality in low-resource countries has been increasing. This pattern is likely to be due to changing risk factor profiles and differences in access to breast cancer early detection and treatment. Risk factors for breast cancer include increasing age, race, menarche history, breast characteristics, reproductive patterns, hormone use, alcohol use, tobacco use, diet, physical activity, and body habitus. Mutations in the BRCA 1 and BRCA 2 tumor suppressor genes are significantly associated with the development of breast and ovarian cancer by the age of 70. Survival depends on both stage and molecular subtype. As there are few signs and symptoms early on, early detection is an important strategy to improve outcomes. Major professional organizations in the United States and elsewhere recommend screening with mammography with appropriate follow up for an abnormal screening test, although they differ somewhat by recommended ages and frequency of screening. Studies suggest a 15%-40% mortality reduction secondary to screening, however, there are also concerns about harms, such as overdiagnosis (5%-54%) and overtreatment leading to long term complications, and false negatives (6%-46%). Identification of women at risk for BRCA1 and BRCA 2 mutations is also recommended with referral for genetic testing. Preventive interventions, such as lifestyle, medical, and surgical options are available for women testing positive for BRCA mutations.

Obesity Increases Prevalence of Colonic Adenomas at Screening Colonoscopy: A Canadian Community-Based Study

BACKGROUND AND AIMS

Obesity is a risk factor for colorectal neoplasia. We examined the influence of obesity and metabolic syndrome (MetS) on prevalence of neoplasia at screening colonoscopy.

METHODS

We evaluated 2020 subjects undergoing first screening colonoscopy. Body mass index (BMI) was calculated at enrolment. Hyperlipidemia (HL), hypertension (HT), and diabetes mellitus (DM) were identified. Details of colonoscopy, polypectomy, and histology were recorded. Odds for adenomas (A) and advanced adenomas (ADV) in overweight (BMI 25.1-30) and obese (BMI > 30) subjects were assessed by multinomial regression, adjusted for covariates. Analyses included relationships between HL, HT, DM, age, tobacco usage, and neoplasia. Discriminatory power of HT, HL, DM, and BMI for neoplasia was assessed by binary logistic regression. Odds were calculated for neoplasia in each colonic segment related to BMI.

RESULTS

A and ADV were commoner in overweight and obese males, obese females, older subjects, and smokers. HL, HT, and DM were associated with increased odds for neoplasia, significantly for A with hypertension. BMI alone predicted neoplasia as well as HT, HL, DM, or combinations thereof. All segments of the colon were affected. Multiple polyps were particularly prevalent in the obese.

CONCLUSIONS

Obesity and MetS are risk factors for colonic neoplasia in a Canadian population.

The fat and the bad: Mature adipocytes, key actors in tumor progression and resistance

Growing evidence has raised the important roles of adipocytes as an active player in the tumor microenvironment. In many tumors adipocytes are in close contact with cancer cells. They secrete various factors that can mediate local and systemic effects. The adipocyte-cancer cell crosstalk leads to phenotypical and functional changes of both cell types, which can further enhance tumor progression. Moreover, obesity, which is associated with an increase in adipose mass and an alteration of adipose tissue, has been established as a risk factor for cancer incidence and cancer-related mortality. In this review, we summarize the mechanisms of the adipocyte-cancer cell crosstalk in both obese and lean conditions as well as its impact on cancer cell growth, local invasion, metastatic spread and resistance to treatments. Better characterization of cancer-associated adipocytes and the key molecular events in the adipocyte-cancer cell crosstalk will provide insights into tumor biology and suggest efficient therapeutic opportunities.

Association of Metabolic Syndrome and Human Papillomavirus Infection in Men and Women Residing in the United States

Background: An estimated 33% of adults in the United States have metabolic syndrome (MetS), which has been associated with an increased risk for various cancer types. Theories of synergism among components of MetS that increase cancer risk via chronic inflammation and oxidative stress have been proposed. We hypothesize that men and women with MetS may have compromised immunological response resulting in increased risk for persistent human papillomavirus (HPV) infection. The goal of this study is to determine the association of MetS with HPV types 6, 11, 16, and 18 and to explore variation of these associations by gender using data from a national survey.Methods: We conducted a retrospective cross-sectional study using data from the National Health and Nutrition Examination Survey.Results: Thirty-two percent of the population sampled met the criteria for MetS (16% men and 33% women). Nineteen percent tested positive for HPV (6, 11, 16, and 18). Prevalence of HPV infection was estimated at 13% for men and 30% for females. MetS was found to be significantly associated with increased risk of HPV6, 11, 16, or 18 in the entire cohort [RR = 1.24; 95% confidence interval (CI), 1.03-1.48] and in females (RR = 1.26; 95% CI, 1.02-1.56). Although the adjusted risk of HPV+ve status was found to be 21% higher in men with MetS compared with those without, this difference did not attain statistical significance.Conclusions: We observed a significant association between metabolic syndrome and HPV sero-positivity among the overall population and among females. Although not significant, a similar effect was noted in men. Further prospective studies are needed to better understand this relationship.Impact: To the best of our knowledge, this is the first study evaluating the impact of metabolic syndrome on HPV positivity in both males and females. Cancer Epidemiol Biomarkers Prev; 26(8); 1321-7. ©2017 AACR.

Increased Risk of Advanced Colorectal Neoplasia Among Korean Men With Metabolic Abnormality and Obesity

BACKGROUND & AIMS

Obesity and metabolic abnormality are risk factors for colorectal cancer and adenoma. We evaluated the risk of advanced colorectal neoplasm (AN) according to metabolic status and obesity in Koreans.

METHODS

We performed a retrospective cross-sectional study of 70,428 individuals in Korea who underwent colonoscopy and whose metabolic state and body mass index were examined, from 2003 through 2012, at Kangbuk Samsung Hospital in Korea. We calculated odds ratios (ORs) for AN in people who were metabolically healthy but obese, people with metabolic abnormality who were not obese, and people with metabolic abnormality who were obese. The reference group was metabolically healthy nonobese peoples. AN was defined as adenoma ≥10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.

RESULTS

No increased risk of AN was observed in the metabolically healthy but obese (OR, 0.99; 95% confidence interval [CI], 0.67-1.46; P = .825) and metabolic abnormality who were not obese groups (OR, 1.01; 95% CI, 0.85-1.21; P = .765). In contrast, risk of AN was increased in the metabolic abnormality who were obese group (OR, 1.33; 95% CI, 1.12-1.58; P = .006). In men, risk of AN showed a greater increase in the metabolic abnormality who were obese group (OR, 1.48; 95% CI, 1.20-1.83; P = .001). This association was not observed in women (OR, 1.21; 95% CI, 0.84-1.75; P = .476).

CONCLUSIONS

Men with 1 or more metabolic abnormality and obesity are at increased risk for AN.

Obesity and cancer: inflammation bridges the two

Obesity is a growing public health problem and affects 35% US adults. Obesity increases the risk of many cancer types and is associated with poor outcomes. Clinical management of cancer patients has been essentially the same between normal weight and obese individuals. Understanding causal mechanisms by which obesity drives cancer initiation and progression is essential for the development of novel precision therapy for obese cancer patients. One caveat is that various mechanisms have been proposed for different cancer types for their progression under obesity. Since obesity is known to have global impact on inflammation, here we will summarize recent literature and discuss the potential of inflammation being the common causal mechanism to promote cancer promotion across cancer types.

Association of adiponectin receptor 1 gene - 106 C > T variant with susceptibility to colorectal cancer

Background

Colorectal cancer (CRC) is the fourth leading cause of cancer-related death around the world and accumulated evidence indicates the association between CRC and obesity and insulin resistance.

Objectives

Regarding the role of adiponectin in obesity and insulin resistance, we explored whether genetic variants in adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) are associated with CRC risk.

Materials and methods

ADIPOQ (rs2241766) and ADIPOR1 (rs2275738) gene variants were genotyped in 261 cases with CRC and 339 controls using PCR-RFLP method.

Results

In this study, no significant difference was observed for ADIPOQ gene rs2241766 variant between the cases and controls. However, carriers of the ADIPOR1 (rs2275738) “CC + CT” genotype compared with “TT” genotype occurred more frequently in the cases with CRC than the controls, and the difference remained significant after adjustment for age, BMI, sex, smoking status, NSAID use, and family history of CRC (P = 0.048; OR = 1.49, 95%CI = 1.01–2.20). Interestingly, after adjustment for confounding factors the ADIPOR1 “CC + TC” genotype compared with “TT” genotype was also associated with an increased risk for obesity in the cases (P = 0.040; OR = 1.86, 95%CI = 1.03–3.36).

Conclusions

Our findings suggest for the first time that the − 106 C > T (rs2275738) variant of ADIPOR1 gene may be a genetic contributor to CRC and obesity risk in the cases with CRC. However, further studies with bigger sample size are needed to validate these findings.

Association between markers of glucose metabolism and risk of colorectal cancer

OBJECTIVES

Independent epidemiological studies have evaluated the association between markers of glucose metabolism (including fasting glucose, fasting insulin, homeostasis model of risk assessment-insulin resistance (HOMA-IR), glycated haemoglobin (HbA1c) and C peptide) and the risk of colorectal cancer (CRC). However, such associations have not been systematically analysed and no clear conclusions have been drawn. Therefore, we addressed this issue using a meta-analysis approach.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed and EMBASE were searched up to May 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

Either a fixed-effects or random-effects model was adopted to estimate overall ORs for the association between markers of glucose metabolism and the risk of CRC. In addition, dose-response, meta-regression, subgroup and publication bias analyses were conducted.

RESULTS

35 studies involving 25 566 patients and 5 706 361 participants were included. Higher levels of fasting glucose, fasting insulin, HOMA-IR, HbA1c and C peptide were all significantly associated with increased risk of CRC (fasting glucose, pooled OR=1.12, 95% CI 1.06 to 1.18; fasting insulin, pooled OR=1.42, 95% CI 1.19 to 1.69; HOMA-IR, pooled OR=1.47, 95% CI 1.24 to 1.74; HbA1c, pooled OR=1.22, 95% CI 1.02 to 1.47 (with borderline significance); C peptide, pooled OR=1.27, 95% CI 1.08 to 1.49). Subgroup analysis suggested that a higher HOMA-IR value was significantly associated with CRC risk in all subgroups, including gender, study design and geographic region. For the relative long-term markers, the association was significant for HbA1c in case-control studies, while C peptide was significantly associated with CRC risk in both the male group and colon cancer.

CONCLUSIONS

The real-time composite index HOMA-IR is a better indicator for CRC risk than are fasting glucose and fasting insulin. The relative long-term markers, HbA1c and C peptide, are also valid predictors for CRC risk. Considering the included case-control studies in the current analysis, more cohort studies are warranted to enhance future analysis.

Genetic Variations in Leptin and Leptin Receptor and Susceptibility to Colorectal Cancer and Obesity

Background

Colorectal cancer (CRC) is the second most commonly diagnosed cancer and the fourth leading cause of cancer-related mortality around the world.

Objectives

With regard to the role of obesity in colorectal cancer (CRC) and the role of leptin in obesity, we investigated whether leptin (LEP) and leptin receptor (LEPR) gene variants are associated with CRC risk.

Patients and Methods

We evaluated LEP (rs7799039) and LEPR (rs1137101) gene variants by using PCR-RFLP method in 261 cases with CRC and 339 controls.

Results

No significant difference was found for rs7799039 and rs1137101gene variants between the cases with CRC and controls. However, the LEPR rs1137101 “GG” genotype compared with “AA” genotype and “AA + AG” genotype was associated with increased risks for obesity, and the differences remained significant after adjustment for confounding factors including age, sex, smoking status, and NSAID use (P = 0.015; OR = 2.42, 95%CI = 1.19 - 4.93 and P = 0.016; OR = 2.28, 95%CI = 1.17 - 4.48, respectively). In addition, the LEPR “G” allele compared with the “A” allele was associated with an increased risk for obesity (P = 0.024; OR = 1.44, 95%CI = 1.05 - 1.98).

Conclusions

Consistent with most previous studies, our findings found no association between LEP (rs7799039) and LEPR (rs1137101) gene variants and CRC risk. However, the LEPR rs1137101 “GG” genotype compared with the “AA” genotype and “AA+AG” genotype was associated with a 2.42-fold and a 2.28-fold increased risk for obesity, respectively.

The impact of BMI on early colorectal neoplastic lesions and the role of endoscopic diagnosis:. An Italian observational study

INTRODUCTION

CRC often arises from polyps: an early detection and resection are effective in decreasing both incidence and mortality rate. Relation between risk factors, adenomas and CRC have been showed, but there is little evidence for overweight association with preneoplastic lesions. This study analyzed the correlation between body mass index (BMI) and primitive site of polyps.

METHODS

We performed a retrospective study, in a period between January 2010 and October 2014. Subjects aged 50 years and older who underwent their first-time screening colonoscopy were included. Reports regarding characteristic of the polyps were collected.

RESULTS

142 patients were enrolled and they were divided into two groups: group I - patients with left sided colonic polyps, and group II - patients who right sided colonic polyps. The ANOVA test-one way, documents a difference between the BMI and the colon localization of polyps.

CONCLUSIONS

Patients with overweight had a higher risk to develop lesions in the left colon compared to patients with normal weight. Despite the fact that Italian epidemiological studies have found a prevalence of polyps of 44-53% in rectal-sigmoid segment, 32-36% in transverse segment and of 14-20% in right segment, we showed an incidence of 26.05% for right sided polyps, which maybe related with the eating habits of the territory.

Association of perioperative blood pressure with long-term survival in rectal cancer patients

Background

Several studies suggested that hypertension is positively related to cancer incidence and mortality. In this study, we investigated the association between perioperative blood pressure (BP) and long-term survival outcomes in patients with rectal cancer.

Methods

This study included a cohort of 358 patients with stages I–III rectal cancer who underwent a curative resection between June 2007 and June 2011. Both pre- and postoperative BPs were measured, by which patients were grouped (low BP: <120/80 mmHg; high BP: ≥120/80 mmHg). The survival outcomes were compared between these two groups. The primary endpoints were disease-free survival (DFS) and cancer-specific survival (CSS).

Results

Univariate analysis showed that patients with high preoperative systolic BP had lower 3-year DFS (67.2% vs. 82.1%, P = 0.041) and CSS rates (81.9% vs. 94.8%, P = 0.003) than patients with low preoperative systolic BP, and the associations remained significant in the Cox multivariate analysis, with the adjusted hazard ratios equal to 1.97 [95% confidence interval (CI) = 1.08–3.60, P = 0.028] and 2.85 (95% CI = 1.00–8.25, P = 0.050), respectively. Similarly, in postoperative evaluation, patients with high systolic BP had significantly lower 3-year CSS rates than those with low systolic BP (78.3% vs. 88.9%, P = 0.032) in univariate analysis. Moreover, high pre- and/or postoperative systolic BP presented as risk factors for CSS in the subgroups of patients who did not have a history of hypertension, with and/or without perioperative administration of antihypertensive drugs.

Conclusions

High preoperative systolic BP was an independent risk factor for both CSS and DFS rates, and high postoperative systolic BP was significantly associated with a low CSS rate in rectal cancer patients. Additionally, our results suggest that rectal cancer patients may get survival benefit from BP control in perioperative care. However, further studies should be conducted to determine the association between BP and CSS and targets of BP control.

Adiponectin and colorectal cancer

Colorectal cancer is an obesity-related malignancy. Adiponectin is an adipokine produced exclusively by adipose tissue, and its concentration in the serum is reduced in obesity. A low serum level of adiponectin is associated with an increased risk of various types of malignancies including colorectal cancer. These facts suggest that the epidemiological link between obesity and cancer may have a significant association with adiponectin. Although numerous studies of colorectal cancer have been reported, the results are conflicting about the anti-cancer effect of adiponectin, and how adiponectin affects carcinogenesis or cancer development remains controversial. Because adiponectin has multiple systemic effects and exists as a high serum concentration protein, the main role of adiponectin should be regulation of homeostasis, and it would not likely act as an anti-cancerous hormone. However, as epidemiological evidence shows, a low adiponectin level may be a basic risk factor for colorectal cancer. We speculate that when the colonic epithelium is stimulated or damaged by another carcinogen under the condition of a low adiponectin level, carcinogenesis is promoted and cancer development is facilitated. In this report, we summarize recent findings of the correlation between adiponectin and colorectal cancer and investigate the effect of adiponectin on colorectal cancer.