Metabolites of tobacco smoking and colorectal cancer risk

Cellular and molecular events in colorectal cancer: biological mechanisms, cell death pathways, drug resistance and signalling network interactions

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide, affecting millions each year. It emerges from the colon or rectum, parts of the digestive system, and is closely linked to both genetic and environmental factors. In CRC, genetic mutations such as APC, KRAS, and TP53, along with epigenetic changes like DNA methylation and histone modifications, play crucial roles in tumor development and treatment responses. This paper delves into the complex biological underpinnings of CRC, highlighting the pivotal roles of genetic alterations, cell death pathways, and the intricate network of signaling interactions that contribute to the disease's progression. It explores the dysregulation of apoptosis, autophagy, and other cell death mechanisms, underscoring the aberrant activation of these pathways in CRC. Additionally, the paper examines how mutations in key molecular pathways, including Wnt, EGFR/MAPK, and PI3K, fuel CRC development, and how these alterations can serve as both diagnostic and prognostic markers. The dual function of autophagy in CRC, acting as a tumor suppressor or promoter depending on the context, is also scrutinized. Through a comprehensive analysis of cellular and molecular events, this research aims to deepen our understanding of CRC and pave the way for more effective diagnostics, prognostics, and therapeutic strategies.

Metabolic profiling of smoking, associations with type 2 diabetes and interaction with genetic susceptibility

BACKGROUND

Smokers are at increased risk of type 2 diabetes (T2D), but the underlying mechanisms are unclear. We investigated if the smoking-T2D association is mediated by alterations in the metabolome and assessed potential interaction with genetic susceptibility to diabetes or insulin resistance.

METHODS

In UK Biobank (n = 93,722), cross-sectional analyses identified 208 metabolites associated with smoking, of which 131 were confirmed in Mendelian Randomization analyses, including glycoprotein acetyls, fatty acids, and lipids. Elastic net regression was applied to create a smoking-related metabolic signature. We estimated hazard ratios (HR) of incident T2D in relation to baseline smoking/metabolic signature and calculated the proportion of the smoking-T2D association mediated by the signature. Additive interaction between the signature and genetic risk scores for T2D (GRS-T2D) and insulin resistance (GRS-IR) on incidence of T2D was assessed as relative excess risk due to interaction (RERI).

FINDINGS

The HR of T2D was 1·73 (95% confidence interval (CI) 1·54 - 1·94) for current versus never smoking, and 38·3% of the excess risk was mediated by the metabolic signature. The metabolic signature and its mediation role were replicated in TwinGene. The metabolic signature was associated with T2D (HR: 1·61, CI 1·46 - 1·77 for values above vs. below median), with evidence of interaction with GRS-T2D (RERI: 0·81, CI: 0·23 - 1·38) and GRS-IR (RERI 0·47, CI: 0·02 - 0·92).

INTERPRETATION

The increased risk of T2D in smokers may be mediated through effects on the metabolome, and the influence of such metabolic alterations on diabetes risk may be amplified in individuals with genetic susceptibility to T2D or insulin resistance.

MASH: MEDIATION ANALYSIS OF SURVIVAL OUTCOME AND HIGH-DIMENSIONAL OMICS MEDIATORS WITH APPLICATION TO COMPLEX DISEASES

Environmental exposures such as cigarette smoking influence health outcomes through intermediate molecular phenotypes, such as the methylome, transcriptome, and metabolome. Mediation analysis is a useful tool for investigating the role of potentially high-dimensional intermediate phenotypes in the relationship between environmental exposures and health outcomes. However, little work has been done on mediation analysis when the mediators are high-dimensional and the outcome is a survival endpoint, and none of it has provided a robust measure of total mediation effect. To this end, we propose an estimation procedure for Mediation Analysis of Survival outcome and High-dimensional omics mediators (MASH) based on sure independence screening for putative mediator variable selection and a second-moment-based measure of total mediation effect for survival data analogous to the R 2 measure in a linear model. Extensive simulations showed good performance of MASH in estimating the total mediation effect and identifying true mediators. By applying MASH to the metabolomics data of 1919 subjects in the Framingham Heart Study, we identified five metabolites as mediators of the effect of cigarette smoking on coronary heart disease risk (total mediation effect, 51.1%) and two metabolites as mediators between smoking and risk of cancer (total mediation effect, 50.7%). Application of MASH to a diffuse large B-cell lymphoma genomics data set identified copy-number variations for eight genes as mediators between the baseline International Prognostic Index score and overall survival.

Characteristics of Cancer Epidemiology Studies That Employ Metabolomics: A Scoping Review

An increasing number of cancer epidemiology studies use metabolomics assays. This scoping review characterizes trends in the literature in terms of study design, population characteristics, and metabolomics approaches and identifies opportunities for future growth and improvement. We searched PubMed/MEDLINE, Embase, Scopus, and Web of Science: Core Collection databases and included research articles that used metabolomics to primarily study cancer, contained a minimum of 100 cases in each main analysis stratum, used an epidemiologic study design, and were published in English from 1998 to June 2021. A total of 2,048 articles were screened, of which 314 full texts were further assessed resulting in 77 included articles. The most well-studied cancers were colorectal (19.5%), prostate (19.5%), and breast (19.5%). Most studies used a nested case-control design to estimate associations between individual metabolites and cancer risk and a liquid chromatography-tandem mass spectrometry untargeted or semi-targeted approach to measure metabolites in blood. Studies were geographically diverse, including countries in Asia, Europe, and North America; 27.3% of studies reported on participant race, the majority reporting White participants. Most studies (70.2%) included fewer than 300 cancer cases in their main analysis. This scoping review identified key areas for improvement, including needs for standardized race and ethnicity reporting, more diverse study populations, and larger studies.

Role of untargeted omics biomarkers of exposure and effect for tobacco research

Tobacco research remains a clear priority to improve individual and population health, and has recently become more complex with emerging combustible and noncombustible tobacco products. The use of omics methods in prevention and cessation studies are intended to identify new biomarkers for risk, compared risks related to other products and never use, and compliance for cessation and reinitation. to assess the relative effects of tobacco products to each other. They are important for the prediction of reinitiation of tobacco use and relapse prevention. In the research setting, both technical and clinical validation is required, which presents a number of complexities in the omics methodologies from biospecimen collection and sample preparation to data collection and analysis. When the results identify differences in omics features, networks or pathways, it is unclear if the results are toxic effects, a healthy response to a toxic exposure or neither. The use of surrogate biospecimens (e.g., urine, blood, sputum or nasal) may or may not reflect target organs such as the lung or bladder. This review describes the approaches for the use of omics in tobacco research and provides examples of prior studies, along with the strengths and limitations of the various methods. To date, there is little consistency in results, likely due to small number of studies, limitations in study size, the variability in the analytic platforms and bioinformatic pipelines, differences in biospecimen collection and/or human subject study design. Given the demonstrated value for the use of omics in clinical medicine, it is anticipated that the use in tobacco research will be similarly productive.

Relationship between metalloproteinase-9 (MMP-9) expression and clinicopathology in colorectal cancer: a cross-sectional study

Introduction

According to the WHO's GLOBOCAN database, ~1,931,590 new colorectal cancer (CRC) cases and 915,607 CRC-related deaths occurred in 2020. The incidence of CRC in Indonesia is 8.6%, making it the fourth most common cancer. With CRC, matrix metalloproteinase-9 (MMP-9) has a role in tumour development and progression, such that patients with a higher MMP-9 expression had poorer survival. This study aimed to analyze the relationship between MMP-9 expression and clinicopathology in CRC patients.

Methods

This was an analytic observational study with a cross-sectional research design. It was conducted from November 2021 to June 2022 with 52 patient tissue samples: these were subjected to MMP-9 immunohistochemistry stain, with the GeneTex (Irvine) MMP-9 monoclonal antibody. Patient data were collected with clinical variables based on medical records and histopathological examination by anatomy pathologists.

Results

Primary tumour location, cancer staging, and histopathology grading were associated with MMP-9 (P=0.016, P=0.001, P=0.049). The more proximal to the primary tumour, the higher the stage of cancer, and the higher the histopathological grade, thus the greater the expression of MMP-9.

Conclusion

A significant relationship existed of primary tumour location, cancer staging, and histopathology grading with MMP-9 expression in CRC patients. MMP-9 expression could be a useful indicator for the clinical assessment of tumour biologic behaviour and prognosis in CRC patients.

Recent advances in nanomedicine preparative methods and their therapeutic potential for colorectal cancer: a critical review

Colorectal cancer (CRC) is a prevalent malignancy that affects a large percentage of the global population. The conventional treatments for CRC have a number of limitations. Nanoparticles have emerged as a promising cancer treatment method due to their ability to directly target cancer cells and regulate drug release, thereby enhancing therapeutic efficacy and minimizing side effects. This compilation examines the use of nanoparticles as drug delivery systems for CRC treatment. Different nanomaterials can be used to administer anticancer drugs, including polymeric nanoparticles, gold nanoparticles, liposomes, and solid lipid nanoparticles. In addition, we discuss recent developments in nanoparticle preparation techniques, such as solvent evaporation, salting-out, ion gelation, and nanoprecipitation. These methods have demonstrated high efficacy in penetrating epithelial cells, a prerequisite for effective drug delivery. This article focuses on the various targeting mechanisms utilized by CRC-targeted nanoparticles and their recent advancements in this field. In addition, the review offers descriptive information regarding numerous nano-preparative procedures for colorectal cancer treatments. We also discuss the outlook for innovative therapeutic techniques in the management of CRC, including the potential application of nanoparticles for targeted drug delivery. The review concludes with a discussion of current nanotechnology patents and clinical studies used to target and diagnose CRC. The results of this investigation suggest that nanoparticles have great potential as a method of drug delivery for the treatment of colorectal cancer.

Identification of plasma metabolites associated with modifiable risk factors and endophenotypes reflecting Alzheimer's disease pathology

Modifiable factors can influence the risk for Alzheimer's disease (AD) and serve as targets for intervention; however, the biological mechanisms linking these factors to AD are unknown. This study aims to identify plasma metabolites associated with modifiable factors for AD, including MIND diet, physical activity, smoking, and caffeine intake, and test their association with AD endophenotypes to identify their potential roles in pathophysiological mechanisms. The association between each of the 757 plasma metabolites and four modifiable factors was tested in the wisconsin registry for Alzheimer's prevention cohort of initially cognitively unimpaired, asymptomatic middle-aged adults. After Bonferroni correction, the significant plasma metabolites were tested for association with each of the AD endophenotypes, including twelve cerebrospinal fluid (CSF) biomarkers, reflecting key pathophysiologies for AD, and four cognitive composite scores. Finally, causal mediation analyses were conducted to evaluate possible mediation effects. Analyses were performed using linear mixed-effects regression. A total of 27, 3, 23, and 24 metabolites were associated with MIND diet, physical activity, smoking, and caffeine intake, respectively. Potential mediation effects include beta-cryptoxanthin in the association between MIND diet and preclinical Alzheimer cognitive composite score, hippurate between MIND diet and immediate learning, glutamate between physical activity and CSF neurofilament light, and beta-cryptoxanthin between smoking and immediate learning. Our study identified several plasma metabolites that are associated with modifiable factors. These metabolites can be employed as biomarkers for tracking these factors, and they provide a potential biological pathway of how modifiable factors influence the human body and AD risk.

Agreement between nicotine metabolites in blood and self-reported smoking status: The Netherlands Epidemiology of Obesity study

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Selfreported smoking status and nicotine metabolites information often agreed.

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In none of never smokers, more than two nicotine metabolites were detected.

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Two or more nicotine metabolites were present in all self-reported regular smokers.

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Metabolic information differed between self-reported regular and occasional smokers.

Introduction

Self-report and nicotine detection are methods to measure smoking exposure and can both lead to misclassification. It is important to highlight discrepancies between these two methods in the context of epidemiological research.

Objective

The aim of this cross-sectional study is to assess the agreements between self-reported smoking status and nicotine metabolite detection.

Methods

Data of 599 participants from the Netherlands Epidemiology of Obesity study were used to compare serum metabolite levels of five nicotine metabolites (cotinine, hydroxy-cotinine, cotinine N-Oxide, norcotinine, 3-hydroxy-cotinine-glucuronide) between self-reported never smokers (n = 245), former smokers (n = 283) and current smokers (n = 71). We assessed whether metabolites were absent or present and used logistic regression to discriminate between current and never smokers based on nicotine metabolite information. A classification tree was derived to classify individuals into current smokers and non/former smokers based on metabolite information.

Results

In 94% of the self-reported current smokers, at least one metabolite was present, versus in 19% of the former smokers and in 10% of the never smokers. In none of the never smokers, cotinine-n-oxide, 3-hydroxy-cotinine-n-glucorinide or norcotinine was present, while at least one of these metabolites was detected in 68% of the self-reported current smokers. The classification tree classified 95% of the participants in accordance to their self-reported smoking status. All self-reported smokers who were classified as non-smokers according to the metabolite profile, had reported to be occasional smokers.

Conclusion

The agreement between self-reported smoking status and metabolite information was high. This indicates that self-reported smoking status is generally reliable.

The risk of colorectal neoplasm in ex- and never-smokers according to urinary cotinine level

To investigate the relationship between urinary cotinine and colorectal neoplasm (CRN).The participants in the health screening cohort of the National Cancer Center who underwent screening colonoscopy between June 2007 and December 2009 were included. A total of 8121 subjects who underwent urinary cotinine measurement within 14 days from the index colonoscopy were included. Cotinine positivity was defined as having a urinary cotinine level ≥50 ng/mL. Follow-up colonoscopy data were collected by reviewing the patients' medical records.Patients were classified according to their urinary cotinine level and self-reported smoking status, and the number of patients with cotinine positivity was 1960 (24.1%). There was no significant difference in the cumulative CRN and advanced CRN (ACRN) risks according to the self-reported smoking status. However, cotinine positivity at the time of index colonoscopy was an independent risk factor for CRN (hazard ratio [HR]= 1.23, P = .006) in follow-up colonoscopy. Moreover, in never- and ex-smokers, cotinine positivity was an independent risk factor for CRN (HR = 1.95, P = .019; HR = 2.12, P = .003, respectively) and ACRN (HR = 8.89, P < .001; HR = 5.03, P = .003) during follow-up colonoscopy. The cumulative incidence of CRN and ACRN was higher in the cotinine-positive never- and ex-smokers than in the cotinine-negative never- and ex-smokers (P < .001 and P = .008, respectively).CRN or ACRN is more likely to occur at follow-up colonoscopy in the urinary cotinine-positive never- and ex-smokers than in the urinary cotinine-negative group. Therefore, urinary cotinine measurements may provide useful information on never- or ex-smokers undergoing screening colonoscopy.

Dysregulated Metabolites Serve as Novel Biomarkers for Metabolic Diseases Caused by E-Cigarette Vaping and Cigarette Smoking

Metabolites are essential intermediate products in metabolism, and metabolism dysregulation indicates different types of diseases. Previous studies have shown that cigarette smoke dysregulated metabolites; however, limited information is available with electronic cigarette (e-cig) vaping. We hypothesized that e-cig vaping and cigarette smoking alters systemic metabolites, and we propose to understand the specific metabolic signature between e-cig users and cigarette smokers. Plasma from non-smoker controls, cigarette smokers, and e-cig users was collected, and metabolites were identified by UPLC-MS (ultra-performance liquid chromatography mass spectrometer). Nicotine degradation was activated by e-cig vaping and cigarette smoking with increased concentrations of cotinine, cotinine N-oxide, (S)-nicotine, and (R)-6-hydroxynicotine. Additionally, we found significantly decreased concentrations in metabolites associated with tricarboxylic acid (TCA) cycle pathways in e-cig users versus cigarette smokers, such as d-glucose, (2R,3S)-2,3-dimethylmalate, (R)-2-hydroxyglutarate, O-phosphoethanolamine, malathion, d-threo-isocitrate, malic acid, and 4-acetamidobutanoic acid. Cigarette smoking significant upregulated sphingolipid metabolites, such as d-sphingosine, ceramide, N-(octadecanoyl)-sphing-4-enine, N-(9Z-octadecenoyl)-sphing-4-enine, and N-[(13Z)-docosenoyl]-sphingosine, versus e-cig vaping. Overall, e-cig vaping dysregulated TCA cycle-related metabolites while cigarette smoking altered sphingolipid metabolites. Both e-cig and cigarette smoke increased nicotinic metabolites. Therefore, specific metabolic signatures altered by e-cig vaping and cigarette smoking could serve as potential systemic biomarkers for early pathogenesis of cardiopulmonary diseases.

Survival of colorectal cancer patients in Brunei Darussalam: comparison between 2002-09 and 2010-17

Background

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. It is the second leading cause of cancer death in men and women in Brunei Darussalam in 2017, posing a major burden on society.

Methods

This retrospective cohort study (n = 1035 patients diagnosed with CRC in Brunei Darussalam from 1st January 2002 until 31st December 2017) aims to compare the overall survival rates of CRC patients (2002–2017), to compare survival rates between two study periods (2002–2009 and 2010–2017) and to identify prognostic factors of CRC. Kaplan-Meier estimator and log-rank tests were performed to analyse the overall survival rates of CRC patients. Multiple Cox regression was performed to determine the prognostic factors of CRC with adjusted hazard ratios (Adj. HRs) reported.

Results

The 1-, 3- and 5-year survival rates of CRC patients are 78.6, 62.5, and 56.0% respectively from 2002 to 2017. The 1-, 3-, and 5-year survival rates of CRC patients for 2002–2009 are 82.2, 69.6, and 64.7%; 77.0, 59.1, and 51.3% for 2010–2017 respectively. A significant difference in CRC patients’ survival rate was observed between the two study periods, age groups, ethnic groups, cancer stages, and sites of cancer (p < 0.05). The Adjusted Hazard Ratios (Adj. HRs) were significantly higher in the 2010–17 period (Adj. HR = 1.78, p < 0.001), older age group ( ≥ 60 years) (Adj. HR = 1.93, p = 0.005), distant cancer (Adj. HR = 4.69, p < 0.010), tumor at transverse colon and splenic flexure of colon (Adj. HR = 2.44, p = 0.009), and lower in the Chinese(Adj. HR = 0.63, p = 0.003).

Conclusion

This study highlights the lower survival rates of CRC patients in 2010–2017, Malays, older patients, distant cancer, and tumors located at the latter half of the proximal colon (transverse colon), and predominantly LCRC (splenic flexure, descending colon, sigmoid colon, overlapping lesion colon and colon (NOS), as well as the rectosigmoid junction and rectum (NOS)). Age, ethnicity, cancer stage, and tumor location are significant prognostic factors for CRC. These findings underscore the importance of public health policies and programmes to enhance awareness on CRC from screening to developing strategies for early detection and management, to reduce CRC-associated mortality.

A review of the role of inositols in conditions of insulin dysregulation and in uncomplicated and pathological pregnancy

Inositols, a group of 6-carbon polyols, are highly bioactive molecules derived from diet and endogenous synthesis. Inositols and their derivatives are involved in glucose and lipid metabolism and participate in insulin-signaling, with perturbations in inositol processing being associated with conditions involving insulin resistance, dysglycemia and dyslipidemia such as polycystic ovary syndrome and diabetes. Pregnancy is similarly characterized by substantial and complex changes in glycemic and lipidomic regulation as part of maternal adaptation and is also associated with physiological alterations in inositol processing. Disruptions in maternal adaptation are postulated to have a critical pathophysiological role in pregnancy complications such as gestational diabetes and pre-eclampsia. Inositol supplementation has shown promise as an intervention for the alleviation of symptoms in conditions of insulin resistance and for gestational diabetes prevention. However, the mechanisms behind these affects are not fully understood. In this review, we explore the role of inositols in conditions of insulin dysregulation and in pregnancy, and identify priority areas for research. We particularly examine the role and function of inositols within the maternal-placental-fetal axis in both uncomplicated and pathological pregnancies. We also discuss how inositols may mediate maternal-placental-fetal cross-talk, and regulate fetal growth and development, and suggest that inositols play a vital role in promoting healthy pregnancy.

Impact of Pre-blood Collection Factors on Plasma Metabolomic Profiles

Demographic, lifestyle and biospecimen-related factors at the time of blood collection can influence metabolite levels in epidemiological studies. Identifying the major influences on metabolite concentrations is critical to designing appropriate sample collection protocols and considering covariate adjustment in metabolomics analyses. We examined the association of age, sex, and other short-term pre-blood collection factors (time of day, season, fasting duration, physical activity, NSAID use, smoking and alcohol consumption in the days prior to collection) with 133 targeted plasma metabolites (acylcarnitines, amino acids, biogenic amines, sphingolipids, glycerophospholipids, and hexoses) among 108 individuals that reported exposures within 48 h before collection. The differences in mean metabolite concentrations were assessed between groups based on pre-collection factors using two-sided t-tests and ANOVA with FDR correction. Percent differences in metabolite concentrations were negligible across season, time of day of collection, fasting status or lifestyle behaviors at the time of collection, including physical activity or the use of tobacco, alcohol or NSAIDs. The metabolites differed in concentration between the age and sex categories for 21.8% and 14.3% metabolites, respectively. In conclusion, extrinsic factors in the short period prior to collection were not meaningfully associated with concentrations of selected endogenous metabolites in a cross-sectional sample, though metabolite concentrations differed by age and sex. Larger studies with more coverage of the human metabolome are warranted.

High placental inositol content associated with suppressed pro-adipogenic effects of maternal glycaemia in offspring: the GUSTO cohort

Background/Objectives

Maternal glycaemia promotes fetal adiposity. Inositol, an insulin sensitizer, has been trialled for gestational diabetes prevention. The placenta has been implicated in how maternal hyperglycaemia generates fetal pathophysiology, but no studies have examined whether placental inositol biology is altered with maternal hyperglycaemia, nor whether such alterations impact fetal physiology. We aimed to investigate whether the effects of maternal glycaemia on offspring birthweight and adiposity at birth differed across placental inositol levels.

Methods

Using longitudinal data from the Growing Up in Singapore Towards healthy Outcomes cohort, maternal fasting glucose (FPG) and 2-hour plasma glucose (2hPG) were obtained in pregnant women by a 75-g oral glucose tolerance test around 26 weeks’ gestation. Relative placental inositol was quantified by liquid chromatography-mass spectrometry. Primary outcomes were birthweight (n = 884) and abdominal adipose tissue (AAT) volumes measured by neonatal MRI scanning in a subset (n = 262) of term singleton pregnancies. Multiple linear regression analyses were performed.

Results

Placental inositol was lower in those with higher 2hPG, no exposure to tobacco smoke antenatally, with vaginal delivery and shorter gestation. Positive associations of FPG with birthweight (adjusted β [95% CI] 164.8 g [109.1, 220.5]) and AAT (17.3 ml [11.9, 22.6] per mmol glucose) were observed, with significant interactions between inositol tertiles and FPG in relation to these outcomes (p < 0.05). Stratification by inositol tertiles showed that each mmol/L increase in FPG was associated with increased birthweight and AAT volume among cases within the lowest (birthweight = 174.2 g [81.2, 267.2], AAT = 21.0 ml [13.1, 28.8]) and middle inositol tertiles (birthweight = 202.0 g [103.8, 300.1], AAT = 19.7 ml [9.7, 29.7]). However, no significant association was found among cases within the highest tertile (birthweight = 81.0 g [−21.2, 183.2], AAT = 0.8 ml [−8.4, 10.0]).

Conclusions

High placental inositol may protect the fetus from the pro-adipogenic effects of maternal glycaemia. Studies are warranted to investigate whether prenatal inositol supplementation can increase placental inositol and reduce fetal adiposity.

Metabolomics Profiles of Smokers from Two Ethnic Groups with Differing Lung Cancer Risk

African American (AA) smokers are at a higher risk of developing lung cancer compared to whites. The variations in the metabolism of nicotine and tobacco-derived carcinogens in these groups were reported previously with the levels of nicotine metabolites and carcinogen-derived metabolites measured using targeted approaches. While useful, these targeted strategies are not able to detect global metabolic changes for use in predicting the detrimental effects of tobacco use and ultimately lung cancer susceptibility among smokers. To address this limitation, we have performed global untargeted metabolomics profiling in urine of AA and white smokers to characterize the pattern of metabolites, identify differentially regulated pathways, and correlate these profiles with the observed variations in lung cancer risk between these two populations. Urine samples from AA (n = 30) and white (n = 30) smokers were used for metabolomics analysis acquired in both positive and negative electrospray ionization modes. LC-MS data were uploaded onto the cloud-based XCMS online (http://xcmsonline.scripps.edu) platform for retention time correction, alignment, feature detection, annotation, statistical analysis, data visualization, and automated systems biology pathway analysis. The latter identified global differences in the metabolic pathways in the two groups including the metabolism of carbohydrates, amino acids, nucleotides, fatty acids, and nicotine. Significant differences in the nicotine degradation pathway (cotinine glucuronidation) in the two groups were observed and confirmed using a targeted LC-MS/MS approach. These results are consistent with previous studies demonstrating AA smokers with lower glucuronidation capacity compared to whites. Furthermore, the d-glucuronate degradation pathway was found to be significantly different between the two populations, with lower amounts of the putative metabolites detected in AA compared to whites. We hypothesize that the differential regulation of the d-glucuronate degradation pathway is a consequence of the variations in the glucuronidation capacity observed in the two groups. Other pathways including the metabolism of amino acids, nucleic acids, and fatty acids were also identified, however, the biological relevance and implications of these differences across ethnic groups need further investigation. Overall, the applied metabolomics approach revealed global differences in the metabolic networks and endogenous metabolites in AA and whites, which could be used and validated as a new potential panel of biomarkers that could be used to predict lung cancer susceptibility among smokers in population-based studies.

The Relationship Between Number of Comorbidities and Age of Colorectal Cancer Diagnosis in US Male Veteran Population: A Single-Center Experience

BACKGROUND

Comorbidities of tobacco and alcohol abuse and obesity are major risk factors for colon carcinogenesis. These risk factors are considered the most prevalent modifiable risk factors linked to malignancies including colorectal cancer (CRC) in both high- and low-income countries. The aim of this study was to investigate the relationship between number of comorbidities and age of CRC diagnosis in US male veteran population.

METHODS

A retrospective single-center study using chart review and the International Classification of Diseases, Ninth Revision (ICD-9) codes to identify patients with a diagnosis of CRC and comorbidities of tobacco abuse, alcohol abuse, hypertension (HTN), diabetes mellitus (DM) and chronic kidney disease (CKD). The primary aim was to study effect of these comorbidities on age of CRC diagnosis. Univariable and then multivariable logistic regression models were fit to age at diagnosis for each patient variable.

RESULTS

A total of 362 patients were included in the study. The mean age of CRC diagnosis was 66.8. Eighty percent were Caucasians, and 20% were African Americans. African Americans were diagnosed with CRC 3.8 years younger compared to Caucasians (P = 0.01). Controlling for other variables in the multivariable model, age at CRC diagnosis was significantly lower for African Americans and for patients with higher total counts for tobacco and alcohol abuse and obesity. HTN, DM and CKD were not associated with a lower age of CRC diagnosis.

CONCLUSIONS

Tobacco and alcohol abuse and obesity have negative cumulative effect on age of CRC diagnosis in US male veteran population. Patients with increasing number of these comorbidities are associated with significantly lower age of CRC diagnosis. It is important to identify veterans with these comorbidities and encourage CRC screening.

Effect of Cotinine-Verified Change in Smoking Status on Risk of Metachronous Colorectal Neoplasia After Polypectomy

BACKGROUND & AIMS

Previous assessments of colorectal neoplasia (CRN) recurrence after polypectomy used self-report to determine smoking status. We evaluated the association between change in smoking status and metachronous CRN risk after polypectomy using cotinine level in urine to determine tobacco exposure.

METHODS

We performed a retrospective study of participants in the Kangbuk Samsung Health Study in Korea who underwent a screening colonoscopy examination and measurement of cotinine in urine samples. Our analysis included 4762 patients who had 1 or more adenomas detected in an index colonoscopy performed between January 2010 and December 2014, and underwent a surveillance colonoscopy, 6 or more months later, until December 2017.

RESULTS

Patients were classified into 4 groups based on the change in cotinine-verified smoking status from index to follow-up colonoscopy (mean interval, 3.2 ± 1.3 y), as follows: remained nonsmokers (n = 2962; group 1), smokers changed to nonsmokers (n = 600; group 2), nonsmokers changed to smokers (n = 138; group 3), and remained smokers (n = 1062; group 4). After adjustment for confounding factors, group 4 had a significantly higher risk of metachronous CRN than group 1 (hazard ratio [HR], 1.54; 95% CI, 1.36-1.73) and group 2 (HR, 1.63; 95% CI, 1.39-1.99). Group 4 also had a higher risk of metachronous advanced CRN than group 1 (HR, 2.84; 95% CI, 1.79-4.53) and group 2 (HR, 2.10; 95% CI, 1.13-3.89). Group 3 had a higher risk of metachronous CRN than group 1 (HR, 1.50; 95% CI, 1.14-1.97) and group 2 (HR, 1.62; 95% CI, 1.20-2.20).

CONCLUSIONS

In a retrospective study of individuals with at least 1 adenoma, we found that cotinine-verified changes in smoking status between index and follow-up colonoscopy are associated with a risk of metachronous CRN. Helping patients quit smoking is important for effective prevention of colorectal cancer.

Association Between Cotinine-verified Smoking Status and Risk of Colorectal Neoplasia

GOALS

We evaluated the association of urinary cotinine-verified smoking status with the risk of colorectal neoplasia (CRN).

BACKGROUND

Many studies have reported the association between the risk of CRN and smoking status, based on self-reported questionnaires. Although self-reported smoking status may be inaccurate, to our knowledge, no study has yet assessed the association between objective biomarkers of tobacco exposure and the risk of CRN.

STUDY

A cross-sectional study was conducted on 96,806 asymptomatic examinees who underwent colonoscopy and urinary cotinine measurements as part of a health check-up. Cotinine-verified current smokers were participants having a urinary cotinine level ≥50 ng/mL.

RESULTS

The mean participant age was 38.4 years, and the proportion of cotinine-verified current smokers was 23.0%. Cotinine-verified current smoking was an independent risk factor for CRN [adjusted odds ratio (AOR), 1.49; 95% confidence interval (CI), 1.42-1.56] and advanced CRN (ACRN) (AOR, 1.79; 95% CI, 1.57-2.05). Moreover, the risk of CRN and ACRN increased with increasing cotinine levels. Among self-reported never smokers, cotinine-verified current smokers had a higher risk of CRN (AOR, 1.77; 95% CI, 1.57-2.00) and ACRN (AOR, 1.94; 95% CI, 1.37-2.74) than cotinine-verified never smokers did, whereas among self-reported current smokers, cotinine-verified never smokers had a lower risk of CRN (AOR, 0.78; 95% CI, 0.70-0.87) and ACRN (AOR, 0.71; 95% CI, 0.52-0.98) than cotinine-verified current smokers did.

CONCLUSIONS

Cotinine-captured smoking status and metabolic variation exhibit associations with CRN more accurately and objectively than self-reporting does, providing clearer evidence for the role of tobacco in the development of CRN.

Deep molecular phenotypes link complex disorders and physiological insult to CpG methylation

Epigenetic regulation of cellular function provides a mechanism for rapid organismal adaptation to changes in health, lifestyle and environment. Associations of cytosine-guanine di-nucleotide (CpG) methylation with clinical endpoints that overlap with metabolic phenotypes suggest a regulatory role for these CpG sites in the body's response to disease or environmental stress. We previously identified 20 CpG sites in an epigenome-wide association study (EWAS) with metabolomics that were also associated in recent EWASs with diabetes-, obesity-, and smoking-related endpoints. To elucidate the molecular pathways that connect these potentially regulatory CpG sites to the associated disease or lifestyle factors, we conducted a multi-omics association study including 2474 mass-spectrometry-based metabolites in plasma, urine and saliva, 225 NMR-based lipid and metabolite measures in blood, 1124 blood-circulating proteins using aptamer technology, 113 plasma protein N-glycans and 60 IgG-glyans, using 359 samples from the multi-ethnic Qatar Metabolomics Study on Diabetes (QMDiab). We report 138 multi-omics associations at these CpG sites, including diabetes biomarkers at the diabetes-associated TXNIP locus, and smoking-specific metabolites and proteins at multiple smoking-associated loci, including AHRR. Mendelian randomization suggests a causal effect of metabolite levels on methylation of obesity-associated CpG sites, i.e. of glycerophospholipid PC(O-36: 5), glycine and a very low-density lipoprotein (VLDL-A) on the methylation of the obesity-associated CpG loci DHCR24, MYO5C and CPT1A, respectively. Taken together, our study suggests that multi-omics-associated CpG methylation can provide functional read-outs for the underlying regulatory response mechanisms to disease or environmental insults.

Targeting regulation of tryptophan metabolism for colorectal cancer therapy: a systematic review

Colorectal cancer (CRC) is one of the most malignant cancers resulting from abnormal metabolism alterations. As one of the essential amino acids, tryptophan has a variety of physiological functions, closely related to regulation of immune system, central nervous system, gastrointestinal nervous system and intestinal microflora. Colorectal cancer, a type of high-grade malignancy disease, stems from a variety of factors and often accompanies inflammatory reactions, dysbacteriosis, and metabolic disorders. Colorectal cancer accompanies inflammation and imbalance of intestinal microbiota and affects tryptophan metabolism. It is known that metabolites, rate-limiting enzymes, and ARH in tryptophan metabolism are associated with the development of CRC. Specifically, IDO1 may be a potential therapeutic target in colorectal cancer treatment. Furthermore, the reduction of tryptophan amount is proportional to the poor quality of life for colorectal cancer patients. This paper aims to discuss the role of tryptophan metabolism in a normal organism and investigate the relationship between this amino acid and colorectal cancer. This study is expected to provide theoretical support for research related to targeted therapy for colorectal cancer. Furthermore, strategies that modify tryptophan metabolism, effectively inhibiting tumor progression, may be more effective for CRC treatment.

Colorectal cancer (CRC) is one of the most malignant cancers resulting from abnormal metabolism alterations.

Surveillance for Cancers Associated with Tobacco Use - United States, 2010-2014

PROBLEM/CONDITION

Tobacco use is the leading preventable cause of cancer, contributing to at least 12 types of cancer, including acute myeloid leukemia (AML) and cancers of the oral cavity and pharynx; esophagus; stomach; colon and rectum; liver; pancreas; larynx; lung, bronchus, and trachea; kidney and renal pelvis; urinary bladder; and cervix. This report provides a comprehensive assessment of recent tobacco-associated cancer incidence for each cancer type by sex, age, race/ethnicity, metropolitan county classification, tumor characteristics, U.S. census region, and state. These data are important for initiation, monitoring, and evaluation of tobacco prevention and control measures.

PERIOD COVERED

2010-2014.

DESCRIPTION OF SYSTEM

Cancer incidence data from CDC's National Program of Cancer Registries and the National Cancer Institute's Surveillance, Epidemiology, and End Results program were used to calculate average annual age-adjusted incidence rates for 2010-2014 and trends in annual age-adjusted incidence rates for 2010-2014. These cancer incidence data cover approximately 99% of the U.S.

POPULATION

This report provides age-adjusted cancer incidence rates for each of the 12 cancer types known to be causally associated with tobacco use, including liver and colorectal cancer, which were deemed to be causally associated with tobacco use by the U.S. Surgeon General in 2014. Findings are reported by demographic and geographic characteristics, percentage distributions for tumor characteristics, and trends in cancer incidence by sex.

RESULTS

During 2010-2014, approximately 3.3 million new tobacco-associated cancer cases were reported in the United States, approximately 667,000 per year. Age-adjusted incidence rates ranged from 4.2 AML cases per 100,000 persons to 61.3 lung cancer cases per 100,000 persons. By cancer type, incidence rates were higher among men than women (excluding cervical cancer), higher among non-Hispanics than Hispanics (for all cancers except stomach, liver, kidney, and cervical), higher among persons in nonmetropolitan counties than those in metropolitan counties (for all cancers except stomach, liver, pancreatic, and AML), and lower in the West than in other U.S. census regions (all except stomach, liver, bladder, and AML). Compared with other racial/ethnic groups, certain cancer rates were highest among whites (oral cavity and pharyngeal, esophageal, bladder, and AML), blacks (colon and rectal, pancreatic, laryngeal, lung and bronchial, cervical, and kidney), and Asians/Pacific Islanders (stomach and liver). During 2010-2014, the rate of all tobacco-associated cancers combined decreased 1.2% per year, influenced largely by decreases in cancers of the larynx (3.0%), lung (2.2%), colon and rectum (2.1%), and bladder (1.3%).

INTERPRETATION

Although tobacco-associated cancer incidence decreased overall during 2010-2014, the incidence remains high in several states and subgroups, including among men, whites, blacks, non-Hispanics, and persons in nonmetropolitan counties. These disproportionately high rates of tobacco-related cancer incidence reflect overall demographic patterns of cancer incidence in the United States and also reflect patterns of tobacco use.

PUBLIC HEALTH ACTION

Tobacco-associated cancer incidence can be reduced through prevention and control of tobacco use and comprehensive cancer-control efforts focused on reducing cancer risk, detecting cancer early, and better assisting communities disproportionately affected by cancer. Ongoing surveillance to monitor cancer incidence can identify populations with a high incidence of tobacco-associated cancers and evaluate the effectiveness of tobacco control programs and policies. Implementation research can be conducted to achieve wider adoption of existing evidence-based cancer prevention and screening programs and tobacco control measures, especially to reach groups with the largest disparities in cancer rates.

Reproducibility of non-fasting plasma metabolomics measurements across processing delays

INTRODUCTION

Processing delays after blood collection is a common pre-analytical condition in large epidemiologic studies. It is critical to evaluate the suitability of blood samples with processing delays for metabolomics analysis as it is a potential source of variation that could attenuate associations between metabolites and disease outcomes.

OBJECTIVES

We aimed to evaluate the reproducibility of metabolites over extended processing delays up to 48 h. We also aimed to test the reproducibility of the metabolomics platform.

METHODS

Blood samples were collected from 18 healthy volunteers. Blood was stored in the refrigerator and processed for plasma at 0, 15, 30, and 48 h after collection. Plasma samples were metabolically profiled using an untargeted, ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) platform. Reproducibility of 1012 metabolites over processing delays and reproducibility of the platform were determined by intraclass correlation coefficients (ICCs) with variance components estimated from mixed-effects models.

RESULTS

The majority of metabolites (approximately 70% of 1012) were highly reproducible (ICCs ≥ 0.75) over 15-, 30- or 48-h processing delays. Nucleotides, energy-related metabolites, peptides, and carbohydrates were most affected by processing delays. The platform was highly reproducible with a median technical ICC of 0.84 (interquartile range 0.68-0.93).

CONCLUSION

Most metabolites measured by the UPLC-MS/MS platform show acceptable reproducibility up to 48-h processing delays. Metabolites of certain pathways need to be interpreted cautiously in relation to outcomes in epidemiologic studies with prolonged processing delays.

Association between cotinine-verified smoking status and risk of nonalcoholic fatty liver disease

BACKGROUND & AIMS

The relationship between cigarette smoking and nonalcoholic fatty liver disease (NAFLD) has been controversial. Most relevant studies have relied on self-reported questionnaires. We aimed to elucidate the association between smoking status and NAFLD using an objective biomarker of tobacco exposure (urinary cotinine) and self-reported questionnaire.

METHODS

A cross-sectional study was conducted on 160 862 asymptomatic examinees who underwent abdominal ultrasonography and urinary cotinine measurements between April 2011 and December 2015. Cotinine-verified current smokers were defined as participants with urinary cotinine levels ≥50 ng/mL.

RESULTS

The mean age of the study population was 36.1 years, and the proportion of men was 51.7%. The proportions of self-reported and cotinine-verified current smokers were 17.6% and 17.7% respectively. After adjusting for confounding factors, self-reported current smoking was associated with an increased risk of NAFLD (adjusted odds ratio [AOR], 1.10; 95% confidence interval [CI], 1.06-1.14). Moreover, among the current smokers, the risk of NAFLD increased with an increase in the amount of cigarette smoking (<10 and ≥10 pack-years vs never smokers; AOR, 1.04 and 1.11; 95% CI, 1.01-1.08 and 1.05-1.16 respectively). Cotinine-verified current smoking was also associated with an increased risk of NAFLD (AOR, 1.10; 95% CI, 1.06-1.14).

CONCLUSIONS

Cotinine-verified current smoking and self-reported current smoking were independent risk factors for NAFLD. Further longitudinal studies are needed to more clearly elucidate the impact of smoking on the development of NAFLD.

Metabolomics Biomarkers for Detection of Colorectal Neoplasms: A Systematic Review

BACKGROUND

Several approaches have been suggested to be useful in the early detection of colorectal neoplasms. Since metabolites are closely related to the phenotype and are available from different human bio-fluids, metabolomics are candidates for non-invasive early detection of colorectal neoplasms.

OBJECTIVES

We aimed to summarize current knowledge on performance characteristics of metabolomics biomarkers that are potentially applicable in a screening setting for the early detection of colorectal neoplasms.

DESIGN

We conducted a systematic literature search in PubMed and Web of Science and searched for biomarkers for the early detection of colorectal neoplasms in easy-to-collect human bio-fluids. Information on study design and performance characteristics for diagnostic accuracy was extracted.

RESULTS

Finally, we included 41 studies in our analysis investigating biomarkers in different bio-fluids (blood, urine, and feces). Although single metabolites mostly had limited ability to distinguish people with and without colorectal neoplasms, promising results were reported for metabolite panels, especially amino acid panels in blood samples, as well as nucleosides in urine samples in several studies. However, validation of the results is limited.

CONCLUSIONS

Panels of metabolites consisting of amino acids in blood and nucleosides in urinary samples might be useful biomarkers for early detection of advanced colorectal neoplasms. However, to make metabolomic biomarkers clinically applicable, future research in larger studies and external validation of the results is required.

Priority and prejudice: does low socioeconomic status bias waiting time for endoscopy? A blinded, randomized survey

INTRODUCTION

An unwanted socioeconomic health gap is observed in Western countries with easily accessible, government-financed health care systems. Survival rates from several malignancies differ between socioeconomic clusters and the disparities remain after adjusting for major co-morbidities and health related behavior. The possibility of biased conduct among health care workers has been proposed as a contributing factor, but evidence is sparse.

METHODS

A blinded, randomized online questionnaire survey was conducted among specialists in gastroenterology in Norway. Each respondent was asked to give priority for colonoscopy to three different referrals. By randomized sequence, half the referrals contained a discreet piece of information indicating low socioeconomic status (SES). The SES information given was focused on known low-status clusters in Norway, namely the morbidly obese and receivers of disability pensions.

RESULTS

There were 107 respondents giving a response rate of 67%. A lower priority was consistently given to the referrals containing information on low SES, but the difference only reached statistical significance (p = .018) for one of the referrals.

CONCLUSION

Information on low SES may influence how referrals for endoscopy are prioritized.

Low serum ω-3 and ω-6 polyunsaturated fatty acids and other metabolites are associated with poor linear growth in young children from rural Malawi

Background: Stunting affects ∼25% of children <5 y of age and is associated with impaired cognitive and motor development and increased morbidity and mortality. The pathogenesis of stunting is poorly understood.Objective: The purpose of this study was to identify altered metabolic pathways associated with child stunting.Design: We measured 677 serum metabolites using liquid chromatography-tandem mass spectrometry in a cross-sectional study of 400 Malawian children aged 12-59 mo, of whom 62% were stunted.Results: A low height-for-age z score (HAZ) was associated with lower serum concentrations of 1) ω-3 (n-3) and ω-6 (n-6) polyunsaturated fatty acids (PUFAs), 2) sulfated neurosteroids, which play a role in brain development, 3) carnitine, a conditionally essential nutrient with an important role in the carnitine shuttle for the metabolism of fatty acids and energy production, and 4) γ-glutamyl amino acids, which represent an altered γ-glutamyl cycle of glutathione metabolism. A low HAZ was associated with significantly higher serum concentrations of 5 biomarkers related to cigarette smoke exposure.Conclusions: This metabolomics study shows a cross-sectional association between stunting and low serum ω-3 and ω-6 long-chain PUFAs, which are essential for growth and development; low sulfated neurosteroids, which play a role in brain development; low carnitine, which is essential for β-oxidation of fatty acids; alterations in glutathione metabolism; and increased serum metabolites that are associated with secondhand tobacco smoke exposure. This trial was registered at www.controlled-trials.com as ISRCTN14597012.

Colorectal Cancer Incidence Trend and Projections in Tunisia (1994 - 2024)

Objectives: The aim of this study was to describe trends of colorectal cancer incidence during the period 1994-2009 and to generate projections until 2024. Methods: The North-Tunisia Cancer Registry (NTCR) was the source of data for patients with CRC. This registry lists, since 1994, cases of malignant tumors in people living in North Tunisia, including the District of Tunis, the north east and the north west. Cases were classified using the International Classification of Diseases for Oncology. Data were analyzed using R software and Joinpoint one was employed to analyse trends. Projections were performed using the Age Period Cohort based on poisson regression. Results: During the period 1994 to 2009, 6,909 new cases of CRC were registered in Northern Tunisia. The age standardized incidence rate (ASR) increased significantly from 6.4/100,000 in 1994 to 12.4/100,000 in 2009. Trends in CRC incidence was significantly rising with an annual percentage change (APC) of + 3,9% [2.8% -5.1%]. Without effective interventions, the predicted CRC ASR would be 39.3/100,000 [CI 95%: 32,9/100,000 - 48,8/100,000] in 2024. Conclusion: The incidence of colorectal cancer is clearly increasing in Tunisia. Strengthening of screening and primary prevention measures is to be recommended.

Global and targeted serum metabolic profiling of colorectal cancer progression

BACKGROUND

Patients with colorectal adenoma polyps (PLPs) are at higher risk for developing colorectal cancer (CRC). However, the development of improved and robust biomarkers to enable the screening, surveillance, and early detection of PLPs and CRC continues to be a challenge. The aim of this study was to identify biomarkers of progression to CRC through metabolomic profiling of human serum samples with a multistage approach.

METHODS

Metabolomic profiling was conducted with the Metabolon platform for 30 CRC patients, 30 PLP patients, and 30 control subjects, and this was followed by the targeted validation of the top metabolites in an additional set of 50 CRC patients, 50 PLP patients, and 50 controls with liquid chromatography-tandem mass spectrometry. Unconditional multivariate logistic regression models, adjusted for covariates, were used to evaluate associations with PLP and CRC risk.

RESULTS

For the discovery phase, 404 serum metabolites were detected, with 50 metabolites showing differential levels between CRC patients, PLP patients, and controls (P for trend < .05). After validation, the 3 top metabolites (xanthine, hypoxanthine, and d-mannose) were validated: lower levels of xanthine and hypoxanthine and higher levels of d-mannose were found in PLP and CRC cases versus controls. A further exploratory analysis of metabolic pathways revealed key roles for the urea cycle and caffeine metabolism associated with PLP and CRC risk. In addition, a joint effect of the top metabolites with smoking and a significant interaction with the body mass index were observed. An analysis of the ratio of hypoxanthine levels to xanthine levels indicated an association with CRC progression.

CONCLUSIONS

These results suggest the potential utility of circulating metabolites as novel biomarkers for the early detection of CRC. Cancer 2017;123:4066-74. © 2017 American Cancer Society.

Cancer incidence in eastern Morocco: cancer patterns and incidence trends, 2005-2012

BACKGROUND

Cancer is one of the major health problems worldwide. In this article, we present for the first time the cancer incidence trends, the distribution and the socioeconomic profile of incident cancer cases in Eastern Morocco over a period of eight years.

METHODS

Retrospective descriptive study of patients diagnosed with cancer at the Hassan II Regional Oncology Center (ROC) since it was created in October 2005 until December 2012. During the study period, the ROC was the only hospital specialized in cancer care in Eastern Morocco.

RESULTS

A total of 7872 incident cases of cancer were registered in Eastern Morocco. Among these incident cases 5220 cases were women and 2652 were men, with a female to male ratio of 1.97. The mean age at diagnosis was 58 years for males and 52 for females and 94% of the patients aged over 30 years. For both sexes combined and for all cancer sites, breast cancer was the commonest followed by cervix uteri, colon-rectum, lung, nasopharynx, and stomach cancers. The most common cancer in women was breast cancer, followed respectively by cervix uteri cancer, colon-rectum cancer, ovary cancer, and stomach cancer. In men, the lung cancer ranked first, followed respectively by colon-rectum cancer, nasopharynx cancer, prostate cancer, and stomach cancer. For most cancers, crude incidence rates (CR) have increased significantly. The CR for all cancers combined has increased from 56.6 to 80.3 per 100,000 females and from 32.3 to 42.6 per 100,000 males during the study period. Patients profile analysis showed that 79% of cancer patients were from urban areas, 83% were unemployed and 85% had no health insurance.

CONCLUSIONS

The distribution of cancers in Eastern Morocco is different from those observed in other regions of Morocco. Unlike most countries, women were much more affected with cancer than men in Eastern Morocco. More importantly, the rates of many cancers are rising. Therefore, our data justify the need to develop effective programs for cancer control and prevention in Eastern Morocco. A better access to cancer care should be a priority of the health policies, given that the majority of cancer patients in Eastern Morocco are unemployed, and do not have medical care coverage.

Mucin expression patterns in histological grades of colonic cancers in Ghanaian population

Introduction

Myriad roles of mucins in normal tissues have been well documented, including lubrication of the epithelial surfaces; protection from physical damage; facilitation in cell-cell signaling and suppression of inflammatory activity. Pathological expression of mucins has been noted in cancer development and progression. This study sought to identify and quantify the types of mucins produced during various histological grades of colon cancer and to assess the diagnostic significance.

Methods

Formalin fixed, paraffin-embedded tissue blocks, comprising three (3) normal colon and twenty-two (22) colon cancer tissues, were retrieved from the archives of the histopathology department of the Komfo Anokye Teaching Hospital. They were stained with Haematoxylin and eosin (H&E) for diagnosis and grading of tumours. Tissues were pre-digested with diastase and stained with Alcian blue (pH 2.5)/Periodic Acid Schiff to characterize the mucin variants present.

Results

Our findings indicated that normal colonic tissues expressed exceptionally high amount of acid mucin and low amount of neutral mucin. However, there was a general decrease in mucin expression in colon cancers compared to normal colon tissues. Additional findings suggested that as cancer progresses from low grade to high grade of adenocarcinoma of the colon, there was generally a considerable decrease in the acid mucin production and an increase in the neutral mucin expression. In contrast, a sizeable subpopulation of high-grade adenocarcinomas of colon showed a rather opposite mucin expression pattern- increase in acid mucin and a decrease in neutral mucin.

Conclusion

As colonic cancer progresses, there are corresponding changes in the mucin types and content such that there are decrease in acid mucin and increase in neutral mucin expressions.

Sex-specific metabolic profiles of androgens and its main binding protein SHBG in a middle aged population without diabetes

The role of androgens in metabolism with respect to sex-specific disease associations is poorly understood. Therefore, we aimed to provide molecular signatures in plasma and urine of androgen action in a sex-specific manner using state-of-the-art metabolomics techniques. Our study population consisted of 430 men and 343 women, aged 20-80 years, who were recruited for the cross-sectional population-based Study of Health in Pomerania (SHIP-TREND), Germany. We used linear regression models to identify associations between testosterone, androstenedione and dehydroepiandrosterone-sulfate (DHEAS) as well as sex hormone-binding globulin and plasma or urine metabolites measured by mass spectrometry. The analyses revealed major sex-specific differences in androgen-associated metabolites, particularly for levels of urate, lipids and metabolic surrogates of lifestyle factors, like cotinine or piperine. In women, in particular in the postmenopausal state, androgens showed a greater impact on the metabolome than in men (especially DHEAS and lipids were highly related in women). We observed a novel association of androstenedione on the metabolism of biogenic amines and only a small sex-overlap of associations within steroid metabolism. The present study yields new insights in the interaction between androgens and metabolism, especially about their implication in female metabolism.

Dietary flavonoid intake and colorectal cancer risk in the European prospective investigation into cancer and nutrition (EPIC) cohort

Flavonoids have been shown to inhibit colon cancer cell proliferation in vitro and protect against colorectal carcinogenesis in animal models. However, epidemiological evidence on the potential role of flavonoid intake in colorectal cancer (CRC) development remains sparse and inconsistent. We evaluated the association between dietary intakes of total flavonoids and their subclasses and risk of development of CRC, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. A cohort of 477,312 adult men and women were recruited in 10 European countries. At baseline, dietary intakes of total flavonoids and individual subclasses were estimated using centre-specific validated dietary questionnaires and composition data from the Phenol-Explorer database. During an average of 11 years of follow-up, 4,517 new cases of primary CRC were identified, of which 2,869 were colon (proximal = 1,298 and distal = 1,266) and 1,648 rectal tumours. No association was found between total flavonoid intake and the risk of overall CRC (HR for comparison of extreme quintiles 1.05, 95% CI 0.93-1.18; p-trend = 0.58) or any CRC subtype. No association was also observed with any intake of individual flavonoid subclasses. Similar results were observed for flavonoid intake expressed as glycosides or aglycone equivalents. Intake of total flavonoids and flavonoid subclasses, as estimated from dietary questionnaires, did not show any association with risk of CRC development.

Identifying biomarkers of dietary patterns by using metabolomics

BACKGROUND

Healthy dietary patterns that conform to national dietary guidelines are related to lower chronic disease incidence and longer life span. However, the precise mechanisms involved are unclear. Identifying biomarkers of dietary patterns may provide tools to validate diet quality measurement and determine underlying metabolic pathways influenced by diet quality.

OBJECTIVE

The objective of this study was to examine the correlation of 4 diet quality indexes [the Healthy Eating Index (HEI) 2010, the Alternate Mediterranean Diet Score (aMED), the WHO Healthy Diet Indicator (HDI), and the Baltic Sea Diet (BSD)] with serum metabolites.

DESIGN

We evaluated dietary patterns and metabolites in male Finnish smokers (n = 1336) from 5 nested case-control studies within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Participants completed a validated food-frequency questionnaire and provided a fasting serum sample before study randomization (1985-1988). Metabolites were measured with the use of mass spectrometry. We analyzed cross-sectional partial correlations of 1316 metabolites with 4 diet quality indexes, adjusting for age, body mass index, smoking, energy intake, education, and physical activity. We pooled estimates across studies with the use of fixed-effects meta-analysis with Bonferroni correction for multiple comparisons, and conducted metabolic pathway analyses.

RESULTS

The HEI-2010, aMED, HDI, and BSD were associated with 23, 46, 23, and 33 metabolites, respectively (17, 21, 11, and 10 metabolites, respectively, were chemically identified; r-range: -0.30 to 0.20; P = 6 × 10-15 to 8 × 10-6). Food-based diet indexes (HEI-2010, aMED, and BSD) were associated with metabolites correlated with most components used to score adherence (e.g., fruit, vegetables, whole grains, fish, and unsaturated fat). HDI correlated with metabolites related to polyunsaturated fat and fiber components, but not other macro- or micronutrients (e.g., percentages of protein and cholesterol). The lysolipid and food and plant xenobiotic pathways were most strongly associated with diet quality.

CONCLUSIONS

Diet quality, measured by healthy diet indexes, is associated with serum metabolites, with the specific metabolite profile of each diet index related to the diet components used to score adherence. This trial was registered at clinicaltrials.gov as NCT00342992.

Colorectal Carcinoma: A General Overview and Future Perspectives in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death. Most cases of CRC are detected in Western countries, with its incidence increasing year by year. The probability of suffering from colorectal cancer is about 4%–5% and the risk for developing CRC is associated with personal features or habits such as age, chronic disease history and lifestyle. In this context, the gut microbiota has a relevant role, and dysbiosis situations can induce colonic carcinogenesis through a chronic inflammation mechanism. Some of the bacteria responsible for this multiphase process include Fusobacterium spp, Bacteroides fragilis and enteropathogenic Escherichia coli. CRC is caused by mutations that target oncogenes, tumour suppressor genes and genes related to DNA repair mechanisms. Depending on the origin of the mutation, colorectal carcinomas can be classified as sporadic (70%); inherited (5%) and familial (25%). The pathogenic mechanisms leading to this situation can be included in three types, namely chromosomal instability (CIN), microsatellite instability (MSI) and CpG island methylator phenotype (CIMP). Within these types of CRC, common mutations, chromosomal changes and translocations have been reported to affect important pathways (WNT, MAPK/PI3K, TGF-β, TP53), and mutations; in particular, genes such as c-MYC, KRAS, BRAF, PIK3CA, PTEN, SMAD2 and SMAD4 can be used as predictive markers for patient outcome. In addition to gene mutations, alterations in ncRNAs, such as lncRNA or miRNA, can also contribute to different steps of the carcinogenesis process and have a predictive value when used as biomarkers. In consequence, different panels of genes and mRNA are being developed to improve prognosis and treatment selection. The choice of first-line treatment in CRC follows a multimodal approach based on tumour-related characteristics and usually comprises surgical resection followed by chemotherapy combined with monoclonal antibodies or proteins against vascular endothelial growth factor (VEGF) and epidermal growth receptor (EGFR). Besides traditional chemotherapy, alternative therapies (such as agarose tumour macrobeads, anti-inflammatory drugs, probiotics, and gold-based drugs) are currently being studied to increase treatment effectiveness and reduce side effects.

Comparison of Collection Methods for Fecal Samples for Discovery Metabolomics in Epidemiologic Studies

BACKGROUND

The gut metabolome may be associated with the incidence and progression of numerous diseases. The composition of the gut metabolome can be captured by measuring metabolite levels in the feces. However, there are little data describing the effect of fecal sample collection methods on metabolomic measures.

METHODS

We collected fecal samples from 18 volunteers using four methods: no solution, 95% ethanol, fecal occult blood test (FOBT) cards, and fecal immunochemical test (FIT). One set of samples was frozen after collection (day 0), and for 95% ethanol, FOBT, and FIT, a second set was frozen after 96 hours at room temperature. We evaluated (i) technical reproducibility within sample replicates, (ii) stability after 96 hours at room temperature for 95% ethanol, FOBT, and FIT, and (iii) concordance of metabolite measures with the putative "gold standard," day 0 samples without solution.

RESULTS

Intraclass correlation coefficients (ICC) estimating technical reproducibility were high for replicate samples for each collection method. ICCs estimating stability at room temperature were high for 95% ethanol and FOBT (median ICC > 0.87) but not FIT (median ICC = 0.52). Similarly, Spearman correlation coefficients (rs) estimating metabolite concordance with the "gold standard" were higher for 95% ethanol (median rs = 0.82) and FOBT (median rs = 0.70) than for FIT (median rs = 0.40).

CONCLUSIONS

Metabolomic measurements appear reproducible and stable in fecal samples collected with 95% ethanol or FOBT. Concordance with the "gold standard" is highest with 95% ethanol and acceptable with FOBT.

IMPACT

Future epidemiologic studies should collect feces using 95% ethanol or FOBT if interested in studying fecal metabolomics. Cancer Epidemiol Biomarkers Prev; 25(11); 1483-90. ©2016 AACR.

Serum Metabolomic Response to Long-Term Supplementation with all-rac-α-Tocopheryl Acetate in a Randomized Controlled Trial

Background. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized controlled cancer prevention trial, showed a 32% reduction in prostate cancer incidence in response to vitamin E supplementation. Two other trials were not confirmatory, however. Objective. We compared the change in serum metabolome of the ATBC Study participants randomized to receive vitamin E to those who were not by randomly selecting 50 men from each of the intervention groups (50 mg/day all-rac-α-tocopheryl acetate (ATA), 20 mg/day β-carotene, both, placebo). Methods. Metabolomic profiling was conducted on baseline and follow-up fasting serum (Metabolon, Inc.). Results. After correction for multiple comparisons, five metabolites were statistically significantly altered (β is the change in metabolite level expressed as number of standard deviations on the log scale): α-CEHC sulfate (β = 1.51, p = 1.45 × 10⁻³⁸), α-CEHC glucuronide (β = 1.41, p = 1.02 × 10⁻³¹), α-tocopherol (β = 0.97, p = 2.22 × 10⁻¹³), γ-tocopherol (β = −0.90, p = 1.76 × 10⁻¹¹), and β-tocopherol (β = −0.73, p = 9.40 × 10⁻⁸). Glutarylcarnitine, beta-alanine, ornithine, and N6-acetyllysine were also decreased by ATA supplementation (β range 0.40 to −0.36), but not statistically significantly. Conclusions. Comparison of the observed metabolite alterations resulting from ATA supplementation to those in other vitamin E trials of different populations, dosages, or formulations may shed light on the apparently discordant vitamin E-prostate cancer risk findings.

Cigarette smoking behaviour and blood metabolomics

BACKGROUND

Identifying circulating metabolites related to cigarette smoking may provide insight into the biological mechanisms of smoking-related diseases and the nature of addiction. However, previous studies are limited, generally small, and have largely targeted a priori metabolites.

METHODS

We examined associations between cigarette smoking and metabolites using an untargeted metabolomics approach in 892 men and women from four studies including participants from Italy, USA, China and Finland. We examined associations between individual log-transformed metabolites and two key smoking phenotypes (current smoking status and cigarettes per day [cig/day]) using linear regression. Fixed-effect meta-analysis was used to combine results across studies. Strict Bonferroni thresholds were used as our significance criteria. We further examined associated metabolites with other metrics of smoking behaviuor (current versus former, former versus never, smoking duration and years since quitting) in the US study.

RESULTS

We identified a total of 25 metabolites associated with smoking behaviours; 24 were associated with current smoking status and eight with cig/day. In addition to three well-established nicotine metabolites (cotinine, hydroxycotinine, cotinine N-oxide), we found an additional 12 xenobiotic metabolites involved in benzoatic (e.g. 3-ethylphenylsulphate) or xanthine metabolism (e.g. 1-methylurate), three amino acids (o-cresol sulphate, serotonin, indolepropionate), two lipids (scyllo-inositol, pregnenolone sulphate), four vitamins or cofactors [e.g. bilirubin (Z,Z)], and one carbohydrate (oxalate).

CONCLUSIONS

We identified associations between cigarette smoking and a diverse range of metabolites. Our findings, with further validation in future studies, have implications regarding aetiology and study design of smoking-related diseases.

Comparing metabolite profiles of habitual diet in serum and urine

BACKGROUND

Diet plays an important role in chronic disease etiology, but some diet-disease associations remain inconclusive because of methodologic limitations in dietary assessment. Metabolomics is a novel method for identifying objective dietary biomarkers, although it is unclear what dietary information is captured from metabolites found in serum compared with urine.

OBJECTIVE

We compared metabolite profiles of habitual diet measured from serum with those measured from urine.

DESIGN

We first estimated correlations between consumption of 56 foods, beverages, and supplements assessed by a food-frequency questionnaire, with 676 serum and 848 urine metabolites identified by untargeted liquid chromatography mass spectrometry, ultra-high performance liquid chromatography tandem mass spectrometry, and gas chromatography mass spectrometry in a colon adenoma case-control study (n = 125 cases and 128 controls) while adjusting for age, sex, smoking, fasting, case-control status, body mass index, physical activity, education, and caloric intake. We controlled for multiple comparisons with the use of a false discovery rate of <0.1. Next, we created serum and urine multiple-metabolite models to predict food intake with the use of 10-fold crossvalidation least absolute shrinkage and selection operator regression for 80% of the data; predicted values were created in the remaining 20%. Finally, we compared predicted values with estimates obtained from self-reported intake for metabolites measured in serum and urine.

RESULTS

We identified metabolites associated with 46 of 56 dietary items; 417 urine and 105 serum metabolites were correlated with ≥1 food, beverage, or supplement. More metabolites in urine (n = 154) than in serum (n = 39) were associated uniquely with one food. We found previously unreported metabolite associations with leafy green vegetables, sugar-sweetened beverages, citrus, added sugar, red meat, shellfish, desserts, and wine. Prediction of dietary intake from multiple-metabolite profiles was similar between biofluids.

CONCLUSIONS

Candidate metabolite biomarkers of habitual diet are identifiable in both serum and urine. Urine samples offer a valid alternative or complement to serum for metabolite biomarkers of diet in large-scale clinical or epidemiologic studies.

Three components of cigarette smoke altered the growth and apoptosis of metastatic colon cancer cells via inducing the synthesis of reactive oxygen species and endoplasmic reticulum stress

Cigarette smoke (CS) is a well-known risk factor for carcinogenesis and has been found to be related to the occurrence and development of colon cancer. In this study, the effect of formaldehyde (FA), benzene (Bz), and isoprene (IP), which are included in main components of CS, on cell viability and apoptosis of SW620 colorectal cancer cells was examined to identify the connection between CS components and colon cancer. In cell viability assay, FA, Bz, and IP decreased cell viability of SW620 cells in a dose dependent manner. In Western blot assay, the protein expression of cell cycle related genes, cyclin D1 & E1, was decreased by FA, Bz, and IP, which corresponded to their inhibitory effect on cell viability. In addition, FA, Bz, and IP increased the protein expression of pro-apoptotic genes, C/EBP homologous protein (CHOP) and Bax, and reduced the protein expression of anti-apoptotic gene, Bcl-2. In reactive oxygen species (ROS) assay using dichlorofluorescin diacetate (DCFH-DA), FA, Bz, and IP increased the ROS production in SW620 cells. In the measurement of apoptotic cells, the numbers of apoptotic cells were increased by the treatment of FA, Bz, and IP. As CHOP is an endoplasmic reticulum (ER)-stress related apoptosis marker of which production is induced by ROS, it was considered that these CS components induce apoptosis of SW620 cells by increasing ROS synthesis and ER-stress. Taken together, these results showed that CS components, i.e., FA, Bz, and IP, inhibited the cell viability of SW620 cells by down-regulating the protein expression of cyclin D1 & E1 and induced apoptosis of SW620 cells by increasing ROS production and simultaneously activating ER-stress.

Alcohol Consumption-Related Metabolites in Relation to Colorectal Cancer and Adenoma: Two Case-Control Studies Using Serum Biomarkers

Alcohol is a known carcinogen that may be associated with colorectal cancer. However, most epidemiologic studies assess alcoholic beverage consumption using self-reported data, leading to potential exposure misclassification. Biomarkers of alcohol consumption may provide an alternative, complementary approach that reduces misclassification and incorporates individual differences in alcohol metabolism. Therefore, we evaluated the relationship between previously identified alcohol consumption-related metabolites and colorectal cancer and adenoma using serum metabolomics data from two studies. Data on colorectal cancer were obtained from a nested case-control study of 502 US adults (252 cases, 250 controls) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Data on colorectal adenoma were obtained from a case-control study of 197 US adults (120 cases, 77 controls) from the Navy Colon Adenoma Study. Unconditional multivariable logistic regression models were fit to calculate odds ratios (OR) and 95% confidence intervals (CI) for eight alcohol consumption-related metabolites identified in a previous analysis: ethyl glucuronide; 4-androstene-3beta,17beta-diol disulfate 1; 5-alpha-androstan-3beta,17beta-diol disulfate; 16-hydroxypalmitate; bilirubin (E,Z or Z,E); cyclo (-leu-pro); dihomo-linoleate (20:2n6); and palmitoleate (16:1n7). We found no clear association between these alcohol consumption-related metabolites and either endpoint. However, we did observe an inverse association between cyclo (-leu-pro) and colorectal adenoma that was only observed in the highest metabolite quantile (OR _{4th vs. 1st Quantile} = 0.30, 95% CI: 0.12–0.78; P-trend = 0.047), but no association for colorectal cancer. In conclusion, there were no adverse associations between alcohol consumption-related metabolites and colorectal cancer or adenoma.

Influence of residential environment and lifestyle on multiple primary malignancies in Taiwan

BACKGROUND

Multiple primary malignancies (MPM) have become increasingly prevalent worldwide. This investigation was aimed at establishing the clinicopathological characteristics of MPM patients and evaluating the impact of the living environment on MPM in the Taiwanese population.

MATERIALS AND METHODS

From January 2009 to December 2013, a total of 8,268 cancer patients were identified in our institutional center. Of these, 125 were diagnosed as MPM and thus enrolled. Data for clinicopathological features and treatment approaches for these MPM patients living in urban or suburb zone were obtained. Findings for the air pollution status in Taiwan were also collected.

RESULTS

The most common cancer match of MPM was esophageal cancer with hypopharyngeal cancer (12.8%), followed by colorectal cancer with gastric cancer (6.4%) and colorectal cancer with breast cancer (5.6%). The air quality was significantly worse in the urban than in the suburban zone and there was a remarkably higher portion of MPM patients in the urban zone suffering from grade III and IV post-chemotherapeutic neutropenia (30.8% vs 15.1%, P=0.036).

CONCLUSIONS

The tumor frequency and site distribution should be taken into the clinical evaluation because there is a relatively high risk of developing MPM. This study also highlighted the potential influence of environmental factors on post-chemotherapeutic neutropenia for patients with MPM.

Metabolomic analysis of prostate cancer risk in a prospective cohort: The alpha-tocolpherol, beta-carotene cancer prevention (ATBC) study

Despite decades of concerted epidemiological research, relatively little is known about the etiology of prostate cancer. As genome-wide association studies have identified numerous genetic variants, so metabolomic profiling of blood and other tissues represents an agnostic, "broad-spectrum" approach for examining potential metabolic biomarkers of prostate cancer risk. To this end, we conducted a prospective analysis of prostate cancer within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort based on 200 cases (100 aggressive) and 200 controls (age- and blood collection date-matched) with fasting serum collected up to 20 years prior to case diagnoses. Ultrahigh performance liquid chromatography/mass spectroscopy and gas chromatography/mass spectroscopy identified 626 compounds detected in >95% of the men and the odds ratio per 1-standard deviation increase in log-metabolite levels and risk were estimated using conditional logistic regression. We observed strong inverse associations between energy and lipid metabolites and aggressive cancer (p = 0.018 and p = 0.041, respectively, for chemical class over-representation). Inositol-1-phosphate showed the strongest association (OR = 0.56, 95% CI = 0.39-0.81, p = 0.002) and glycerophospholipids and fatty acids were heavily represented; e.g., oleoyl-linoleoyl-glycerophosphoinositol (OR = 0.64, p = 0.004), 1-stearoylglycerophosphoglycerol (OR=0.65, p = 0.025), stearate (OR=0.65, p = 0.010) and docosadienoate (OR = 0.66, p = 0.014). Both alpha-ketoglutarate and citrate were associated with aggressive disease risk (OR = 0.69, 95% CI = 0.51-0.94, p = 0.02; OR = 0.69, 95% CI = 0.50-0.95, p = 0.02), as were elevated thyroxine and trimethylamine oxide (OR = 1.65, 95% CI = 1.08-2.54, p = 0.021; and OR = 1.36, 95% CI = 1.02-1.81, p = 0.039). Serum PSA adjustment did not alter the findings. Our data reveal several metabolomic leads that may have pathophysiological relevance to prostate carcinogenesis and should be examined through additional research.

The Microbiome and Cancer: Is the 'Oncobiome' Mirage Real?

Investigations focused on the interplay between the human microbiome and cancer development, herein termed the 'oncobiome', have been growing at a rapid rate. However, these studies to date have primarily demonstrated associative relationships rather than causative ones. We pose the question of whether this emerging field of research is a 'mirage' without a clear picture, or truly represents a paradigm shift for cancer research. We propose the necessary steps needed to answer crucial questions and push the field forward to bring the mirage into a tangible reality.

Refining and validating a two-stage and web-based cancer risk assessment tool for village doctors in China

The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web- based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..