Molecular Mechanisms of Alcohol-Induced Colorectal Carcinogenesis

Carbohydrate quality, not quantity, linked to reduced colorectal cancer incidence and mortality in US populations: evidence from a prospective study

BACKGROUND

Carbohydrates have been implicated in colorectal cancer (CRC) risk, but the specific impact of carbohydrate quality and quantity on CRC susceptibility in US populations remains unclear.

METHODS

We followed 101,694 participants from Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The carbohydrate quality index (CQI) and low-carbohydrate diet score (LCDs) were used to evaluate the daily carbohydrate quality and quantity separately, where higher scores indicated greater adherence. Cox proportional hazards regression was used to compute HRs and 95% CIs for incident CRC and related death. Subgroup analyses were conducted to identify potential effect modifiers.

RESULTS

During follow-up, we documented 1085 incident cases of CRC, of whom 311 died from CRC. Individuals in the highest compared with the lowest quartiles of CQI had a lower CRC incidence (Q4 vs Q1: HR 0.80, 95% CI 0.67-0.96, Ptrend = 0.012) and mortality (Q4 vs Q1: HR 0.61, 95% CI 0.44-0.86, Ptrend = 0.004). The inverse association between CQI and CRC risk was observed for distal colon and rectum but not for proximal colon cancer. Regarding mortality, this association was only significant for rectum cancer. Subgroup analyses indicated this inverse association of CQI with CRC risk was only observed in participants with lower LCDs. No significant associations were found between LCDs and CRC incidence or mortality.

CONCLUSIONS

Our findings suggest focusing on higher quality, rather than restricting the quantity, of carbohydrate consumption may be an effective approach to reduce the risk of CRC in the US population, particularly for distal colon and rectal cancers.

Birth Cohort Colorectal Cancer (CRC): Implications for Research and Practice

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity-including and extending beyond rising EOCRC-can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology.

The relationship between physical activity, self-efficacy and quality of life in colorectal cancer survivors: a multicenter cross-sectional study

PURPOSE

This study aimed to investigate the current situation and factors influencing physical activity, self-efficacy, and quality of life in Chinese colorectal cancer survivors. Additionally, this study explored the associations between physical activity, self-efficacy, and quality of life.

METHODS

A multicenter, cross-sectional study was conducted, involving 173 colorectal cancer survivors with a mean age of 59 years. Self-reported data on basic demographic characteristics, physical activity, self-efficacy, and quality of life were collected.

RESULTS

Among 173 colorectal cancer survivors, 90 (52.0%) were engaged in manual work. The self-efficacy score was found to be 25.99 ± 7.10, while the global health status score was 54.96 ± 21.56. Global health status was associated with sex, residence, chemoradiotherapy, and monthly income (p < 0.01). The self-efficacy score exhibited a significant positive correlation with quality of life, while demonstrating a negative correlation with symptom scores (p < 0.01). Recreational PA scores were positively associated with global health status (P < 0.05). Self-efficacy, recreational physical activity during winter, and whether the participants underwent chemoradiotherapy explained 29.3% of the variance in quality of life among colorectal cancer survivors.

CONCLUSIONS

Colorectal cancer survivors exhibited low levels of physical activity, self-efficacy, and quality of life. Their health is influenced by self-efficacy, recreational physical activity, and chemoradiotherapy. When developing intervention plans for colorectal cancer survivorship, it is crucial to consider survivors' self-efficacy and the type of physical activity in which they engage.

Zinc intake, SLC30A8 rs3802177 polymorphism, and colorectal cancer risk in a Korean population: a case-control study

PURPOSE

Zinc is an essential micronutrient involving in multiple enzymatic reactions of human metabolism and biological functions affecting the cancer development. However, the relationship between dietary zinc intake and colorectal cancer (CRC) risk has been unclear. Herein, our study investigated the relationship between dietary zinc intake and CRC risk, and examined how the SLC30A8 rs3802177 genetic variant affects this association.

METHODS

A total of 1431 CRC cases and 2704 controls were selected to investigate the relationship between dietary zinc intake and CRC risk. After excluding individuals without genotype data, 1097 CRC cases and 1559 controls were used to evaluate the interaction between dietary zinc intake and the rs3802177 polymorphism in CRC risk. The odds ratios (ORs) and 95% confidence intervals (CIs) were measured using unconditional logistic regression models.

RESULTS

Higher dietary zinc intake was inversely associated with the risk of CRC in the total population [adjusted OR (aOR) = 0.80, 95% CI 0.66-0.96, p for trend = 0.018]. In the codominant model, G+ carriers of the SLC30A8 rs3802177 with higher consumption of zinc were observed to have a significantly lower risk of CRC in all participants (p for interaction = 0.020). In females, GG carriers with higher zinc intake showed a stronger protective effect against the development of CRC (p for interaction = 0.008).

CONCLUSIONS

In summary, our findings suggest an inverse association between dietary zinc intake and CRC risk, and this relationship may be modified by SLC30A8 rs3802177 polymorphism.

Factors influencing advanced colorectal neoplasm anatomic site distribution in China: An epidemiological study based on colorectal cancer screening data

OBJECTIVE

Existing studies indicate that advanced colorectal neoplasms exhibit distinct clinical and biological traits based on anatomical sites. However, in China, especially for advanced colorectal neoplasms, there's limited information available on these traits. Our primary objective is to comprehensively study the characteristics of advanced colorectal neoplasm patients in different anatomical sites in China.

METHODS

We selected information from the colorectal cancer screening database in Tianjin, China, since 2010 as the study subject. We chose valid information from 3113 patients with comprehensive data and diagnosed advanced colorectal neoplasms (ANs) from a pool of 19,308 individuals to be included in the study. We then conducted further analysis to examine the correlation between these epidemiological data and tumor location.

RESULTS

Among the 3113 patients, neoplasms in the left side of the colon accounted for the largest proportion, while neoplasms in the right side of the colon had the smallest proportion, followed by rectal neoplasms. The highest proportion of advanced colorectal neoplasms was found among men. In the age group of 39-49 years old, the proportion of left late-stage advanced colon neoplasms was equal to that of right late-stage advanced colon neoplasms, while late-stage advanced rectal neoplasms increased with age. Smoking, drinking, and a history of colon cancer in first-degree relatives showed statistically significant associations with the location distribution of advanced colorectal neoplasms. A history of appendicitis, appendectomy, cholecystitis, or cholecystectomy did not significantly affect the location distribution of advanced colorectal neoplasms. However, among patients with such histories, there was a statistically significant relationship between advanced colon neoplasms on the right and those on the left and in the rectum. Similar results were observed for BMI.

CONCLUSION

Our research findings demonstrate that advanced colorectal neoplasms display unique epidemiological characteristics depending on their anatomical locations, and these distinctions deviate from those observed in Western populations. These insights contribute to a more comprehensive understanding of the topic and offer valuable guidance for future research in China. We advocate for further investigations centered on the anatomical location of colorectal neoplasms to enhance the precision of colorectal cancer (CRC) screening and treatment.

Comprehensive Analysis of Early-onset Colorectal Cancer: A Review

Early-onset colorectal cancer (CRC), which refers to CRC diagnosed in individuals below the age of 50 years, is a growing health concern that presents unique challenges in diagnosis, treatment, and long-term outcomes. Although approximately 70% of early-onset CRC cases are sporadic, with no apparent family history, approximately 25% have a familial component, and up to 20% may be associated with germline mutations, indicating a higher prevalence compared with the general population. Despite the progress in identifying the environmental, molecular, and genetic risk factors of early-onset CRC, the underlying causes for the global increase in its incidence remain unclear. This comprehensive review aims to provide a thorough analysis of early-onset CRC by examining the trends associated with its incidence, clinical and pathological characteristics, risk factors, molecular and genetic profiles, prognosis and screening strategies. By deepening our understanding of early-onset CRC, significant advances related to improving the outcomes and alleviating the burden of this disease on individuals, families, and healthcare systems can be achieved.

Cancer risk based on alcohol consumption levels: a comprehensive systematic review and meta-analysis

OBJECTIVES

Alcohol consumption is a well-established risk factor for cancer. Despite extensive research into the relationship between alcohol consumption and cancer risk, the effect of light alcohol consumption on cancer risk remains a topic of debate. To contribute to this discourse, we conducted a comprehensive systematic review and meta-analysis.

METHODS

Our systematic review aimed to investigate the associations between different levels of alcohol consumption and the risk of several cancer types. We focused on analyzing prospective associations using data from 139 cohort studies. Among them, 106 studies were included in the meta-analysis after a quantitative synthesis.

RESULTS

Our analysis did not find a significant association between light alcohol consumption and all-cause cancer risk (relative risk, 1.02; 95% confidence interval, 0.99 to 1.04), but we observed a dose-response relationship. Light alcohol consumption was significantly associated with higher risks of esophageal, colorectal, and breast cancers. Light to moderate drinking was associated with elevated risks of esophageal, colorectal, laryngeal, and breast cancers. Heavy drinking was also found to contribute to the risk of stomach, liver, pancreas, and prostate cancers, thereby increasing the risk of almost all types of cancer. Additionally, females generally had lower cancer risks compared to males.

CONCLUSIONS

Our findings highlight that cancer risks extend beyond heavy alcohol consumption to include light alcohol consumption as well. These findings suggest that there is no safe level of alcohol consumption associated with cancer risk. Our results underscore the importance of public health interventions addressing alcohol consumption to mitigate cancer risks.

Research Recommendations for Selected IARC-Classified Agents: Impact and Lessons Learned

BACKGROUND

The International Agency for Research on Cancer (IARC) Monographs program assembles expert working groups who publish a critical review and evaluation of data on agents of interest. These comprehensive reviews provide a unique opportunity to identify research needs to address classification uncertainties. A multidisciplinary expert review and workshop held in 2009 identified research gaps and needs for 20 priority occupational chemicals, metals, dusts, and physical agents, with the goal of stimulating advances in epidemiological studies of cancer and carcinogen mechanisms. Overarching issues were also described.

OBJECTIVES

In this commentary we review the current status of the evidence for the 20 priority agents identified in 2009. We examine whether identified Research Recommendations for each agent were addressed and their potential impact on resolving classification uncertainties.

METHODS

We reviewed the IARC classifications of each of the 20 priority agents and identified major new epidemiological and human mechanistic studies published since the last evaluation. Information sources were either the published Monograph for agents that have been reevaluated or, for agents not yet reevaluated, Advisory Group reports and literature searches. Findings are described in view of recent methodological developments in Monographs evidence evaluation processes.

DISCUSSION

The majority of the 20 priority agents were reevaluated by IARC since 2009. The overall carcinogen classifications of 9 agents advanced, and new cancer sites with either "sufficient" or "limited" evidence of carcinogenicity were also identified for 9 agents. Examination of published findings revealed whether evidence gaps and Research Recommendations have been addressed and highlighted remaining uncertainties. During the past decade, new research addressed a range of the 2009 recommendations and supported updated classifications for priority agents. This supports future efforts to systematically apply findings of Monograph reviews to identify research gaps and priorities relevant to evaluation criteria established in the updated IARC Monograph Preamble. https://doi.org/10.1289/EHP12547.

Young-onset colorectal cancer

In the past decades the incidence of colorectal cancer (CRC) in people under the age of 50 years has increased, which is referred to as early-onset CRC or young-onset CRC (YO-CRC). YO-CRC is expected to account for 11% of colon cancers and 23% of rectal cancers by 2030. This trend is observed in different parts of the world and in both men and women. In 20% of patients with YO-CRC, a hereditary cancer syndrome is found as the underlying cause; however, in the majority of patients no genetic predisposition is present. Beginning in the 1950s, major changes in lifestyle such as antibiotic use, low physical activity and obesity have affected the gut microbiome and may be an important factor in YO-CRC development. Owing to a lack of screening, patients with YO-CRC are often diagnosed with advanced-stage disease. Long-term treatment-related complications should be taken into account in these younger patients, making the more traditional sequential approaches of drug therapy not always the most appropriate option. To better understand the underlying mechanism and define relationships between environmental factors and YO-CRC development, long-term prospective studies are needed with lifestyle data collected from childhood.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

Associations between Folate and Alcohol Consumption with Colorectal Tumor Ki67 Expression in the Southern Community Cohort Study

Folate is hypothesized to accelerate cell proliferation in colorectal cancer (CRC) by supporting DNA synthesis, while alcohol is also linked to gastrointestinal epithelial proliferation, despite biological antagonism of folate. We report associations between folate and alcohol consumption with the proliferation marker Ki67 in CRC tumors from the Southern Community Cohort Study. Tumor samples were obtained from formalin-fixed paraffin-embedded tissue blocks. The percentage of cells expressing Ki67 was measured immunohistochemically. Exposures were assessed via questionnaire pre-diagnosis. Associations were assessed via linear regression. In 248 cases (40-78 years), neither dietary folate, folic acid supplements, nor total folate intake were associated with Ki67. Folic acid supplement use was associated with Ki67 in distal/rectal tumors (β [95% confidence interval]: 7.5 [1.2-13.8], p = .02) but not proximal tumors (-1.4 [-7.1-4.3], p=.62). A positive trend for total folate was observed for distal/rectal tumors (1.6 [0.0-3.3] per 200 μcg, p-trend=.05). Heavy drinking (women: ≥1 drink/day, men: ≥2 drinks/day) was associated with higher Ki67 (6.4 [1.0-11.9], vs. nondrinkers, p=.02), especially for distal/rectal tumors (10.4 [1.6-19.1], p=.02). Negative interaction between alcohol, total folate was observed for distal/rectal tumors (p-interaction=.06). Modest associations between folate, alcohol consumption and distal/rectal tumor Ki67 expression suggest accelerated proliferation, consistent with folate's role in DNA synthesis.

Capacity of a Microbial Synbiotic To Rescue the In Vitro Metabolic Activity of the Gut Microbiome following Perturbation with Alcohol or Antibiotics

The human gut microbiome contributes crucial bioactive metabolites that support human health and is sensitive to perturbations from the ingestion of alcohol and antibiotics. We interrogated the response and recovery of human gut microbes after acute alcohol or broad-spectrum antibiotic administration in a gut model simulating the luminal and mucosal colonic environment with an inoculated human microbiome. Both alcohol and antibiotic treatments reduced the production of major short-chain fatty acids (SCFAs) (acetate, propionate, and butyrate), which are established modulators of human health. Treatment with a microbial synbiotic restored and enhanced gut function. Butyrate and acetate production increased by up to 29.7% and 18.6%, respectively, relative to untreated, dysbiotic samples. In parallel, treatment led to increases in the relative abundances of beneficial commensal organisms not found in the synbiotic (e.g., Faecalibacterium prausnitzii and the urolithin-producing organism Gordonibacter pamelaeae) as well as species present in the synbiotic (e.g., Bifidobacterium infantis), suggesting synergistic interactions between supplemented and native microorganisms. These results lead us to conclude that functional shifts in the microbiome, evaluated by both metabolite production and specific taxonomic compositional changes, are an appropriate metric to assess microbiome "recovery" following a dysbiosis-inducing disruption. Overall, these findings support the execution of randomized clinical studies to determine whether a microbial synbiotic can help restore microbiome function after a disruption. IMPORTANCE The human gut microbiome is sensitive to disruptions by common stressors such as alcohol consumption and antibiotic treatment. In this study, we used an in vitro system modeling the gut microbiome to investigate whether treatment with a microbial synbiotic can help restore microbiome function after stress. We find that a complex gut community treated with alcohol or antibiotics showed reduced levels of production of short-chain fatty acids, which are critical beneficial molecules produced by a healthy gut microbiota. Treatment of stressed communities with a microbial synbiotic resulted in the recovery of SCFA production as well as an increase in the abundance of beneficial commensal organisms. Our results suggest that treatment with a microbial synbiotic has the potential to restore healthy gut microbiome function after stress and merits further investigation in clinical studies.

The comparison of risk factors for colorectal neoplasms at different anatomical sites

AIM

Both the clinical manifestation and molecular characteristics of colorectal cancer (CRC) vary according to the anatomical site. We explored the risk factors for four groups of colorectal neoplasms (CRN) at different anatomical sites.

METHODS

We extracted data from the database of Tianjin Colorectal Cancer Screening Program from 2010 to 2020. According to the CRN anatomical sites, patients were divided into four groups: the proximal colon group, the distal colon group, the rectum group, and the multiple colorectal sites. Binary logistic regression analysis was used to explore the differences in risk factors of CRN at different anatomical sites.

RESULTS

The numbers of patients with CRN in the proximal colon, distal colon, rectum, and multiple colorectal sites were 4023, 6920, 3657, and 7938, respectively. Male sex was associated with a higher risk from the proximal colon to the rectum. Advanced age and obesity were also significantly associated with overall colorectal CRN risk, but there were some differences between men and women. Smoking was associated with CRN risk only in the distal colon and rectum in both men and women. Frequent alcohol consumption and family history of CRC in first-degree relatives (FDRs) were associated with the risk of multisite colorectal CRN only in males.

CONCLUSIONS

We observed differences in advanced age, obesity, smoking, alcohol consumption, and family history of colorectal cancer at different anatomical sites of colorectal neoplasms. These factors vary by gender.

A novel prognostic model based on urea cycle-related gene signature for colorectal cancer

Background

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the world. This study aimed to develop a urea cycle (UC)-related gene signature that provides a theoretical foundation for the prognosis and treatment of patients with CRC.

Methods

Differentially expressed UC-related genes in CRC were confirmed using differential analysis and Venn diagrams. Univariate Cox and least absolute shrinkage and selection operator regression analyses were performed to identify UC-related prognostic genes. A UC-related signature was created and confirmed using distinct datasets. Independent prognostic predictors were authenticated using Cox analysis. The Cell-type Identification by Estimating Relative Subsets of RNA Transcripts algorithm and Spearman method were applied to probe the linkage between UC-related prognostic genes and tumor immune-infiltrating cells. The Human Protein Atlas database was used to determine the protein expression levels of prognostic genes in CRC and normal tissues. Verification of the expression levels of UC-related prognostic genes in clinical tissue samples was performed using real-time quantitative polymerase chain reaction (qPCR).

Results

A total of 49 DEUCRGs in CRC were mined. Eight prognostic genes (TIMP1, FABP4, MMP3, MMP1, CD177, CA2, S100P, and SPP1) were identified to construct a UC-related gene signature. The signature was then affirmed using an external validation set. The risk score was demonstrated to be a credible independent prognostic predictor using Cox regression analysis. Functional enrichment analysis revealed that focal adhesion, ECM-receptor interaction, IL-17 signaling pathway, and nitrogen metabolism were associated with the UC-related gene signature. Immune infiltration and correlation analyses revealed a significant correlation between UC-related prognostic genes and differential immune cells between the two risk subgroups. Finally, the qPCR results of clinical samples further confirmed the results of the public database.

Conclusion

Taken together, this study authenticated UC-related prognostic genes and developed a gene signature for the prognosis of CRC, which will be of great significance in the identification of prognostic molecular biomarkers, clinical prognosis prediction, and development of treatment strategies for patients with CRC.

The research progress in the interaction between Candida albicans and cancers

Candida albicans is an opportunistic pathogenic fungus, which tends to infect the host with defective immune function including cancer patients. A growing number of studies have shown that C. albicans infection increases the host susceptibility to cancer such as oral, gastric, and colorectal cancer. Cancer and anti-cancer treatment may also affect the colonization of C. albicans. C. albicans may promote the development of cancer by damaging mucosal epithelium, inducing the production of carcinogens, triggering chronic inflammation including Th17 cell-mediated immune response. In this article, we aim to elaborate the interaction between C. albicans and cancers development and summarize the potential molecular mechanisms, so as to provide theoretical basis for prevention, diagnosis and treatment of cancers.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.