Prospective evaluation of dietary and lifestyle pattern indices with risk of colorectal cancer in a cohort of younger women

Dietary patterns and colorectal cancer risk: Global Cancer Update Programme (CUP Global) systematic literature review

BACKGROUND

The 2018 World Cancer Research Fund/American Institute for Cancer Research Third Expert Report, including studies up to 2015, determined limited-no conclusion evidence on dietary patterns and colorectal cancer (CRC) risk due to insufficient data and varying pattern definitions.

OBJECTIVES

This updated review synthesized literature on dietary patterns and CRC risk/mortality.

METHODS

PubMed and Embase were searched through 31 March, 2023, for randomized controlled trials (RCTs) and prospective cohort studies on adulthood dietary patterns. Patterns were categorized by derivation method: a priori, a posteriori, or hybrid, and were then descriptively reviewed in relation to the primary outcomes: CRC risk or mortality. The Global Cancer Update Programme Expert Committee and Expert Panel independently graded the evidence on the likelihood of causality using predefined criteria.

RESULTS

Thirty-two dietary scores from 53 observational studies and 3 RCTs were reviewed. Limited-suggestive evidence was concluded for higher alignment with a priori-derived patterns: Mediterranean, healthful plant-based index, Healthy Eating Index (HEI)/alternate HEI, and Dietary Approaches to Stop Hypertension (DASH), in relation to lower CRC risk. Common features across these diets included high plant-based food intake and limited red/processed meat. Hybrid-derived patterns: the empirical dietary index for hyperinsulinemia (EDIH) and the empirical dietary inflammatory pattern (EDIP), showed strong-probable evidence for increased CRC risk. Evidence for a priori-derived low-fat dietary interventions and a posteriori-derived patterns was graded as limited-no conclusion. By cancer subsite, higher alignment with Mediterranean diet showed limited-suggestive evidence for lower rectal cancer risk, and that with HEI/alternate HEI and DASH showed limited-suggestive evidence for lower colon and rectal cancer risks. EDIH and EDIP showed strong-probable evidence for increased colon cancer risks. All exposure-mortality pairs and other pattern-outcome associations were graded as limited-no conclusion.

CONCLUSIONS

This review highlights the role of dietary patterns in CRC risk/mortality, providing insights for future research and public health strategies. This review was registered at PROSPERO as CRD42022324327 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022324327).

Dietary-Lifestyle Patterns and Colorectal Cancer Risk: Global Cancer Update Programme (CUP Global) Systematic Literature Review

BACKGROUND

Although healthy dietary and lifestyle factors have been individually linked to lower colorectal cancer (CRC) risks, recommendations for whole diet-lifestyle patterns remained unestablished because of limited studies and inconsistent pattern definitions.

OBJECTIVES

This updated review synthesized literature on dietary-lifestyle patterns and CRC risk/mortality.

METHODS

PubMed and Embase were searched through March 31, 2023 for randomized controlled trials and prospective cohort studies examining adulthood dietary patterns combined with modifiable lifestyle factors such as adiposity, smoking, alcohol consumption, physical activity, and/or others. Patterns were categorized by derivation methods: a priori, a posteriori, and a hybrid combining both; and were then descriptively reviewed for the primary outcomes: CRC risk or mortality. The Global Cancer Update Programme Expert Committee and Expert Panel independently graded the evidence on the likelihood of causality using predefined grading criteria.

RESULTS

Thirty-three observational studies were reviewed. "Strong-probable" evidence was concluded for higher levels of alignment with the a priori-derived World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recommendations score and lower CRC risk; and "limited-suggestive" evidence for the American Cancer Society guidelines and Healthy Lifestyle Index with lower CRC risk (mainly because of concerns about risk of bias for confounding). A posteriori-derived patterns lack firm evidence (only 1 study). "Strong-probable" evidence was concluded for higher levels of alignment with the Empirical Lifestyle Index for Hyperinsulinemia hybrid pattern and higher CRC risk. By cancer subsite, only the WCRF/AICR recommendations score showed "strong-probable" evidence with lower colon cancer risk. All exposure-mortality pairs were graded "limited-no conclusion." The evidence for other pattern-outcome associations was graded as "limited-no conclusion."

CONCLUSIONS

Adopting a healthy pattern of diet, maintaining a healthy weight, staying physically active, and embracing health-conscious habits, such as avoiding tobacco and moderating alcohol, are collectively associated with a lower CRC risk. Healthy lifestyle habits are key to primary CRC prevention. This study was registered at PROSPERO as CRD42022324327 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022324327).

Risk Factors and Prevention of Cancer and CVDs: A Chicken and Egg Situation

Cardiovascular diseases and cancer are the two primary causes of mortality worldwide. Although traditionally regarded as distinct pathologies, they share numerous pathophysiological mechanisms and risk factors, including chronic inflammation, insulin resistance, obesity, and metabolic dysregulation. Notably, several cancers have been identified as closely linked to cardiovascular diseases, including lung, breast, prostate, and colorectal cancers, as well as hematological malignancies, such as leukemia and lymphoma. Additionally, renal and pancreatic cancers exhibit a significant association with cardiovascular complications, partly due to shared risk factors and the cardiotoxic effects of cancer therapies. Addressing the overlapping risk factors through lifestyle modifications-such as regular physical activity, a balanced diet, and cessation of smoking and alcohol-has proven effective in reducing both CV and oncological morbidity and mortality. Furthermore, even in patients with established cancer, structured interventions targeting physical activity, nutritional optimization, and smoking cessation have been associated with improved outcomes. Beyond lifestyle modifications, pharmacological strategies play a crucial role in the prevention of both diseases. Several cardiovascular medications, including statins, aspirin, beta-blockers, and metformin, exhibit pleiotropic effects that extend beyond their primary indications, demonstrating potential anti-neoplastic properties in preclinical and observational studies. Recently, novel therapeutic agents have garnered attention for their possible cardioprotective and metabolic benefits. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is), initially developed for managing type 2 diabetes, have shown CV and renal protective effects, alongside emerging evidence of their role in modulating cancer-related metabolic pathways. Inclisiran, a small interfering RNA targeting PCSK9, effectively lowers LDL cholesterol and may contribute to reducing CV risk, with potential implications for tumor biology. Additionally, sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor, has revolutionized heart failure management by improving hemodynamic parameters and exerting anti-inflammatory effects that may have broader implications for chronic disease prevention. Given the intricate interplay between CVD and cancer, further research is essential to clarify the exact mechanisms linking these conditions and assessing the potential of CV therapies in cancer prevention. This review aims to examine shared risk factors, consider the role of pharmacological and lifestyle interventions, and emphasize crucial epidemiological and mechanistic insights into the intersection of CV and oncological health.

Lifestyle scores and their potential to estimate the risk of multiple non-communicable disease-related endpoints: a systematic review

BACKGROUND

Lifestyle scores have emerged as a practical tool to assess the risk of major non-communicable diseases (NCDs). However, most of them are primarily developed for single NCDs. Given the common risk factors for some of the major NCDs, we conducted a systematic review to evaluate the potential of existing lifestyle scores in predicting the risk of multiple NCD-related endpoints.

METHODS

PubMed, Web of Science, the Cochrane Library, Embase, and Google Scholar were searched from inception to October 2024. We included observational studies assessing the association between lifestyle scores and the risk of morbidity or mortality of multiple NCDs, including type 2 diabetes (T2D), cardiovascular disease (CVD), and cancer.

RESULTS

Of 16,138 unique records identified by the search, 56 eligible studies were included in the systematic review, consisting of 48 cohort studies, 5 case-control studies, 2 case-cohort studies, and 1 cross-sectional study from 16 countries. 15 lifestyle scores were identified to estimate the risk of 32 NCDs, with HLIBMI being the most reported score (14/56, 25.0%). Moderate to strong associations were found between the 15 lifestyle scores and the risk of developing and dying from multiple types of cancers, CVDs, and T2D. Healthy lifestyle scores including additional risk factors (i.e., blood pressure, blood glucose, and waist circumference) aside from major risk factors (i.e., Body Mass Index (BMI), smoking, and diet) seemed to have a stronger ability to estimate NCDs risk than scores including only major risk factors.

CONCLUSION

All 15 simple lifestyle scores were shown to estimate the risk of multiple NCDs endpoints, although some scores were originally developed to estimate the risk of single diseases only. Therefore, further research is required to identify which lifestyle score is most effective for assessing the risk of multiple NCD-related endpoints in a head-to-head comparison.

Allura Red AC is a xenobiotic. Is it also a carcinogen?

Merriam-Webster and Oxford define a xenobiotic as any substance foreign to living systems. Allura Red AC (a.k.a., E129; FD&C Red No. 40), a synthetic food dye extensively used in manufacturing ultra-processed foods and therefore highly prevalent in our food supply, falls under this category. The surge in synthetic food dye consumption during the 70s and 80s was followed by an epidemic of metabolic diseases and the emergence of early-onset colorectal cancer in the 1990s. This temporal association raises significant concerns, particularly given the widespread inclusion of synthetic food dyes in ultra-processed products, notably those marketed toward children. Given its interactions with key contributors to colorectal carcinogenesis such as inflammatory mediators, the microbiome, and DNA damage, there is growing interest in understanding Allura Red AC's potential impact on colon health as a putative carcinogen. This review discusses the history of Allura Red AC, current research on its effects on the colon and rectum, potential mechanisms underlying its impact on colon health, and provides future considerations. Indeed, although no governing agencies classify Allura Red AC as a carcinogen, its interaction with key guardians of carcinogenesis makes it suspect and worthy of further molecular investigation. The goal of this review is to inspire research into the impact of synthetic food dyes on colon health.

Metabolic Dysregulation and Cancer Risk Program (MeDOC): a transdisciplinary approach to obesity-associated cancers

With the escalating prevalence of obesity, the association between obesity and cancer is a growing public health concern. Obesity will soon surpass tobacco smoking as the most important preventable cause of cancer. Obesity-driven mechanisms can alter cell functions to induce metabolic changes, chronic inflammation, and insulin resistance that are believed to contribute to cancer risk and development; yet the specific underlying biological mechanisms of obesity-related cancer development are largely unknown. The Metabolic Dysregulation and Cancer Risk Program: a transdisciplinary approach to obesity-associated cancers (MeDOC) is a trans-National Cancer Institute research initiative supported by the Division of Cancer Control and Population Sciences, the Division of Cancer Biology, the Division of Cancer Prevention, and the Center to Reduce Cancer Health Disparities. The overall purpose of the MeDOC Program is to advance our understanding of the underlying mechanisms that connect obesity, metabolic dysregulation, and increased obesity cancer risk as well as identify markers that will enhance cancer risk prediction, improve screening for high-risk individuals, and identify targets for preventive and therapeutic interventions for cancer interception or treatment. This report describes the funded research projects, the Coordinating Center, and the goals of the MeDOC program.

Dietary and Lifestyle Insulinemic Potential Indices and Risk Factors of Metabolic Syndrome Among Overweight and Obese Individuals: A Cross-Sectional Study

Background

As a worldwide pandemic, metabolic syndrome (MetS) is related with high disease burden. The emergence of multiple chronic diseases can be attributed to unfavorable dietary and lifestyle choices made by individuals, with hyperinsulinemia and insulin resistance as the underlying causes. Current study sought to assess the relationship between the Empirical Dietary Index for Hyperinsulinemia (EDIH) and the Empirical Lifestyle Index for Hyperinsulinemia (ELIH) and MetS risk factors.

Methods

This cross-sectional study involved 339 individuals between the ages of 20 and 50, who were either obese or overweight, and were recruited from Tabriz, Iran. In this study, a validated semi-quantitative Food Frequency Questionnaire (FFQ) with 168 questions was used to assess individuals' food consumption. Blood tests were performed to assess total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG) levels, as well as blood glucose and insulin levels.

Results

After multivariable adjustment, among tertiles of EDIH, systolic blood pressure (SBP) and TG were significantly different. Also, SBP, diastolic blood pressure (DBP), and HDL-C significantly differed across tertiles of ELIH. In multivariate-adjusted models, individuals classified in the highest tertile of EDIH demonstrated elevated ORs in relation to FBG levels [OR: 1.035 (1.004-1.068; P < .05)], and the second tertile of ELIH was inversely associated with SBP [OR: 0.966 (0.935-0.999; P < .05)], DBP [OR: 0.972 (0.948-0.997; P < .05)], TG in the model I [OR: 0.991 (0.983-0.999; P < .05)], and model II [OR: 0.991 (0.983-0.999; P < .05)].

Conclusion

Considering the findings of our study, higher insulinemic dietary potential, indicated by EDIH, can be related to higher odds of FBG and decreased odds of TG as risk factors of MetS. Furthermore, our findings suggest that individuals with a higher ELIH may potentially exhibit lower SBP and DBP levels. Nevertheless, further experimental and long-term investigations are necessary to fully comprehend this association.

The global burden and trends analysis of early-onset colorectal cancer attributable to dietary risk factors in 204 countries and territories, 1990-2019: a secondary analysis for the global burden of disease study 2019

Background

Rising trends in early-onset colorectal cancer (CRC) burden have been observed, but the distribution and temporal patterns of early-onset CRC attributable to dietary risks remain unclear.

Objectives

This study aimed to estimate the burden of early-onset CRC attributable to dietary risk factors globally, regionally, and nationally, by age and sex, from 1990 to 2019.

Methods

The absolute number and age-specific rates (ASR) of diet-related early-onset CRC burden, as well as summary exposure value (SEV) of attributable dietary risk factors, were extracted from the Global Burden of Disease (GBD) Study 2019. The temporal changes in the burden between 1990 and 2019 were analyzed by calculating the percentage change in the absolute number of burden and the estimated annual percentage change (EAPC) in ASR of burden. The annualized rates of change (ARC) were calculated to evaluate the variation trend of SEV.

Results

In 2019, diet-related early-onset CRC caused 30,096 (95% UI: 23,148 to 36,091) death cases and 1,465,755 (95% UI: 1,126,489 to 1,761,661) DALYs worldwide, accounting for 34.8% deaths and 34.4% DALYs of overall early-onset CRC, respectively. Moreover, a diet low in milk (responsible for 16.5% [95% UI: 11.1 to 21.9%] of DALYs in 2019), low in whole grains (15.2% [95% UI: 5.9 to 19.9%]), low in calcium (14.3% [95% UI: 10.7 to 18.9%]), high in red meat (5.3% [95% UI: 1.7 to 9.5%]), high in processed meat (2.5% [95% UI: 0.9 to 4.0%]), and low in fiber (2.3% [95% UI: 0.9 to 4.2%]) were early-onset CRC attributable dietary risk factors. The age-specific DALYs rate of early-onset CRC attributable to each dietary risk factor generally showed an increasing trend globally between 1990 and 2019, except for low intake of fiber (EAPC = -0.57, 95% CI: -0.76 to -0.38). In addition, from 1990 to 2019, males have a higher burden than females and this gap may continue to widen due to the increasing difference between the sexes in most dietary risk factors. Furthermore, dietary risks-attributable early-onset CRC burden has shifted from regions with high socio-demographic index (SDI) to high-middle and middle SDI quintiles with uncontrolled dietary risks.

Conclusion

Early-onset CRC remains a concerning issue globally, and effective prevention and modification of dietary risk factors holds great promise to reduce early-onset CRC-related burden. Prioritizing diet improvement for males is critical and urgent for CRC control efforts, particularly for those living in developing countries with ongoing dietary pattern transition.

Unraveling the complexities of early-onset colorectal cancer: a perspective on dietary and microbial influences

While advances in screening have resulted in declining rates of colorectal cancer (CRC) among adults ≥50 years of age since the mid-2000s, the incidence of early-onset CRC (EOCRC) has steadily increased over the last decade. This increase is not fully accounted for by hereditary factors, and the hypothesis that a sedentary lifestyle and obesity are the primary culprits is not fully supported by recent reports indicating that many affected individuals lead active lifestyles, maintain normal weight, and are otherwise healthy. Attention has shifted toward dietary patterns, notably the consumption of processed and ultra-processed foods found in Western diets, which are suspected of disrupting the gut microbiome balance that potentially leads to EOCRC. The impact of antibiotic use on the gut microbiome is also posited as a contributing factor, given its rising prevalence in medical and agricultural practices. We propose that a paradigm shift is necessary for EOCRC research, moving beyond metabolic factors to a broader exploration of dietary and microbial influences. Future research must prioritize understanding the relationship between dietary habits, particularly processed food intake, antibiotic exposure, and gut microbiome dynamics, to unravel the complex etiology of EOCRC. This will be crucial in developing comprehensive preventive strategies to address the increasing incidence of this malignancy in younger populations.

A Perspective Review on Diet Quality, Excess Adiposity, and Chronic Psychosocial Stress and Implications for Early-Onset Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although the overall incidence of CRC has been decreasing over the past 40 y, early-onset colorectal cancer (EOCRC), which is defined as a CRC diagnosis in patients aged >50 y has increased. In this Perspective, we highlight and summarize the association between diet quality and excess adiposity, and EOCRC. We also explore chronic psychosocial stress (CPS), a less investigated modifiable risk factor, and EOCRC. We were able to show that a poor-quality diet, characterized by a high intake of sugary beverages and a Western diet pattern (high intake of red and processed meats, refined grains, and foods with added sugars) can promote risk factors associated with EOCRC development, such as an imbalance in the composition and function of the gut microbiome, presence of chronic inflammation, and insulin resistance. Excess adiposity, particularly obesity onset in early adulthood, is a likely contributor of EOCRC. Although the research is sparse examining CPS and CRC/EOCRC, we describe likely pathways linking CPS to tumorigenesis. Although additional research is needed to understand what factors are driving the uptick in EOCRC, managing body weight, improving diet quality, and mitigating psychosocial stress, may play an important role in reducing an individual's risk of EOCRC.

Dietary consumption trend and its correlation with global cancer burden: A quantitative and comprehensive analysis from 1990 to 2019

OBJECTIVE

The aim of this study was to estimate the effect of dietary consumption on cancer burden and formulate an effective solution.

METHODS

Dietary consumption, number of cancer deaths, disability-adjusted life years, and corresponding age-standardized rates were extracted from the Global Burden of Disease Study 2019. The annual percentage change was used to quantify the temporal trends in cancer burden and dietary consumption. Age, sex, location, and sociodemographic index were stratified to further analyze the discrepancy in cancer burden attributable to dietary intake.

RESULTS

Five cancers (breast, colon and rectal, tracheal, bronchus and lung, esophageal, and stomach) were documented to be associated with dietary consumption in the Global Burden of Disease database. The age-standardized death rate and age-standardized disability-adjusted life years rate in 2019 were 7.56 and 1168.77 per 100 000 population, respectively. For most cancers, the age-standardized death rate and age-standardized disability-adjusted life years rate displayed a decreasing tendency, with annual percentage change varying from -3.60 to -0.29 and from -3.64 to -0.03 from 1990 to 2019, respectively. The age-standardized death rate and age-standardized standardized disability-adjusted life years rate were higher in men than in women (9.68 vs 5.79 and 213.16 vs 129.18, respectively). In addition, the diet-related cancer burden in higher sociodemographic index regions exceeded that in lower sociodemographic index regions.

CONCLUSION

Dietary consumption has a considerable influence on cancer burden, among which colon and rectal cancer burden account for the largest proportion. Increasing the intake of whole grains, milk, fiber, calcium, vegetables, and fruits and reducing the consumption of processed meat and sodium are instrumental in lowering the disease burden of cancer. The quantitative analysis of dietary consumption would provide a more detailed reference for diet-related decision makers and raise awareness of healthy dietary habits in diet management departments, food production enterprises, and the general public.

Dietary and lifestyle indices for hyperinsulinemia and colorectal cancer risk: a case-control study

BACKGROUND

The incidence of colorectal cancer (CRC) has increased in Iran, and determining the dietary patterns that can contribute to reducing or increasing the risk of CRC will help better control this disease. Therefore, in the current study, we assessed the association between the empirical lifestyle index for hyperinsulinemia (ELIH) and the empirical dietary index for hyperinsulinemia (EDIH) with the CRC odds.

METHODS

The present case (n = 71)-control (n = 142) study was carried out in several CRC surgical units of hospitals in Tehran, Iran. A semi-quantitative food frequency questionnaire containing 168 items was used to assess participants' dietary intakes. The EDIH and ELIH scores were calculated by food groups and some variables such as body mass index and physical activity. Logistic regression models were applied to evaluate the association between the EDIH and ELIH scores with CRC odds.

RESULTS

According to baseline features of the study participants, there were significant differences between the controls and cases in ELIH score, fiber intake, taking aspirin, and family history of CRC in first- and second-degree relatives. Also, we found that the odds of CRC increased significantly in the last tertile compared to the first tertile in EDIH and ELIH in the adjusted model (odds ratio (OR) = 3.12; 95% confidence interval (CI): 1.30-7.48 and OR = 4.72; 95% CI: 1.15-19.39, respectively).

CONCLUSIONS

In conclusion, the result of this study indicated that CRC odds was significantly greater in subjects with higher EDIH and ELIH scores. Also, according to the results of this study, lifestyle and diet with insulinemic potential can influence the CRC risk.

The synthetic food dye, Red 40, causes DNA damage, causes colonic inflammation, and impacts the microbiome in mice

The incidence of colorectal cancer (CRC) among young people has been on the rise for the past four decades and its underlying causes are only just starting to be uncovered. Recent studies suggest that consuming ultra-processed foods and pro-inflammatory diets may be contributing factors. The increase in the use of synthetic food colors in such foods over the past 40 years, including the common synthetic food dye Allura Red AC (Red 40), coincides with the rise of early-onset colorectal cancer (EOCRC). As these ultra-processed foods are particularly appealing to children, there is a growing concern about the impact of synthetic food dyes on the development of CRC. Our study aimed to investigate the effects of Red 40 on DNA damage, the microbiome, and colonic inflammation. Despite a lack of prior research, high levels of human exposure to pro-inflammatory foods containing Red 40 highlight the urgency of exploring this issue. Our results show that Red 40 damages DNA both in vitro and in vivo and that consumption of Red 40 in the presence of a high-fat diet for 10 months leads to dysbiosis and low-grade colonic inflammation in mice. This evidence supports the hypothesis that Red 40 is a dangerous compound that dysregulates key players involved in the development of EOCRC.

Plant-based dietary patterns, genetic predisposition and risk of colorectal cancer: a prospective study from the UK Biobank

BACKGROUND

Plant-based dietary patterns may affect colorectal cancer (CRC) related outcomes, while risks differ in the quality of plant foods. We aimed to examine the association of plant-based diet quality with risks of CRC incidence and mortality and whether this association was modified by genetic risk.

METHODS

This prospective cohort study included 186,675 participants free of cancer when the last dietary recall was completed. We calculated three plant-based diet indices (PDIs), i.e., the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI) representing adherence to plant-based diets with diverse quality. Genetic risk was characterized using a weighted polygenic risk score (PRS), capturing overall risk variants associated with CRC. Hazard ratios (HR) and 95% confidential intervals (CI) were estimated by the cause-specific Cox proportional hazards model.

RESULTS

Over a follow-up of 9.5 years, 2163 cases and 466 deaths from CRC were documented. The HR of CRC incidence was 0.88 (95% CI, 0.81-0.96) and 0.91 (95% CI, 0.84-0.99) per 10-score increase in PDI and hPDI, respectively. Compared to the lowest quartile, PDI, hPDI, and uPDI in the highest quartile were associated with a 13% decrease, a 15% decrease, and a 14% increase in risk of incident CRC, respectively. We found a joint association of genetic risk and PDIs with incident CRC, with the highest hazard observed in those carrying higher PRS and adhering to lower-quality PDIs. The inverse association of PDI and hPDI with CRC mortality was pronounced in males.

CONCLUSIONS

Our results suggested that better adherence to overall and healthful plant-based diets was associated with a lower risk of CRC, whereas an unhealthful plant-based diet was associated with a higher CRC risk. Consumption of a higher-quality plant-based diet combined with decreased genetic risk conferred less susceptibility to CRC. Our findings highlighted the importance of food quality when adhering to a plant-based dietary pattern for CRC prevention in the general population.

Knowledge mapping of early-onset colorectal cancer from 2000 to 2022: A bibliometric analysis

The incidence of early-onset colorectal cancer (EO-CRC), diagnosed in patients younger than 50 years, has increased in incidence alarmingly over the past few decades, while overall incidence and mortality of colorectal cancer are stabilizing or declining in many high-income countries. These unfavorable changes have raised significant concerns and led to extensive research, resulting in a surge in studies on EO-CRC. Our aim was to obtain a more comprehensive understanding of the current state of this field and to identify prospective research directions by performing a bibliometric analysis of EO-CRC. A total of 1952 papers on EO-CRC published from 2000 to 2022 were identified after a thorough search of the Web of Science Core Collection. The United States dominated this field, with Harvard University contributing the greatest number of papers, while the journal Familial Cancer (n = 52) published the most articles. Cooperation network analysis revealed close internal cooperation among countries, institutions and authors. Based on reference and keyword analysis, high-frequency keywords showed several popular research directions, including epidemiology (incidence, young patients, age of onset, etc.), risk factors (obesity, family history, lynch syndrome, etc.) and molecular characterization (germline mutation, genome wide association, MLH1, etc.). Overall, our research provides an overview of the current status in this field, which we hope will give researchers a comprehensive perspective on the present trends within this domain.

Dietary Inflammatory and Insulinemic Potentials, Plasma Metabolome and Risk of Colorectal Cancer

The inflammatory and insulinemic potentials of diets have been associated with colorectal cancer risk. However, it is unknown whether the plasma metabolite profiles related to inflammatory diets, or to insulinemic diets, underlie this association. The aim of this study was to evaluate the association between metabolomic profile scores related to the food-based empirical dietary inflammatory patterns (EDIP), the empirical dietary index for hyperinsulinemia (EDIH), and plasma inflammation (CRP, IL-6, TNFα-R2, adiponectin) and insulin (C-peptide) biomarkers, and colorectal cancer risk. Elastic net regression was used to derive three metabolomic profile scores for each dietary pattern among 6840 participants from the Nurses' Health Study and Health Professionals Follow-up Study, and associations with CRC risk were examined using multivariable-adjusted logistic regression, in a case-control study of 524 matched pairs nested in both cohorts. Among 186 known metabolites, 27 were significantly associated with both the EDIP and inflammatory biomarkers, and 21 were significantly associated with both the EDIH and C-peptide. In men, odds ratios (ORs) of colorectal cancer, per 1 standard deviation (SD) increment in metabolomic score, were 1.91 (1.31-2.78) for the common EDIP and inflammatory-biomarker metabolome, 1.12 (0.78-1.60) for EDIP-only metabolome, and 1.65 (1.16-2.36) for the inflammatory-biomarkers-only metabolome. However, no association was found for EDIH-only, C-peptide-only, and the common metabolomic signatures in men. Moreover, the metabolomic signatures were not associated with colorectal cancer risk among women. Metabolomic profiles reflecting pro-inflammatory diets and inflammation biomarkers were associated with colorectal cancer risk in men, while no association was found in women. Larger studies are needed to confirm our findings.

Adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations throughout the life course and risk of colorectal cancer precursors

BACKGROUND

Despite the increasing incidence in colorectal cancer (CRC) among the young population, the involvement of modifiable early-life exposures is understudied.

METHODS

We prospectively investigated the association of lifestyle score, which measures adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations, in adolescence and adulthood with risk of CRC precursors in 34,509 women enrolled in the Nurses' Health Study II. Participants reported adolescent diet in 1998 and subsequently underwent at least one lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression for clustered data.

RESULTS

During follow-up (1998-2015), 3036 women had at least one adenoma, and 2660 had at least one serrated lesion. In multivariable analysis, per unit increase in adolescent WCRF/AICR lifestyle score was not associated with risk of total adenoma or serrated lesions, in contrast to adult WCRF/AICR lifestyle score (OR = 0.92, 95% CI: 0.87-0.97, Ptrend = 0.002 for total adenoma; and OR = 0.86, 95% CI: 0.81-0.92, Ptrend < 0.001 for total serrated lesions).

CONCLUSION

Adherence to the 2018 WCRF/AICR recommendations during adulthood but not during adolescence was associated with a lower risk of CRC precursors.

Interactive effect of the empirical lifestyle index for insulin resistance with the common genetic susceptibility locus rs2423279 for colorectal cancer

The aim of this study is to examine the empirical insulinemic potential consisting of dietary and lifestyle factors and the interactive effect with the common genetic susceptibility locus rs2423279 on the risk of colorectal cancer (CRC). This case-control study was conducted with 923 CRC patients and 1846 controls. The empirical measures for assessing the insulinemic potential, namely, the empirical dietary index for hyperinsulinemia (EDIH), for insulin resistance (EDIR), the empirical lifestyle index for hyperinsulinemia (ELIH), and for insulin resistance (ELIR), were calculated based on semiquantitative food frequency questionnaire and lifestyle questionnaire. A genetic variant of rs2423279 was genotyped. The CRC patients were more likely to score in the highest quartile for the ELIH (OR 2·90, Q4 v. Q1, 95 % CI (2·01, 4·19), Pfor trend < 0·001), EDIR (OR 3·32, Q4 v. Q1, 95 % CI (2·32, 4·74), P < 0·001) and ELIR (OR 2·79, Q4 v. Q1, 95 % CI (1·96, 3·97), P < 0·001) than the controls. The significant effect between the ELIR, which assesses dietary and lifestyle patterns related to insulin resistance, and C allele carriers of rs2423279 was stronger than that for homozygous T allele carriers (OR 2·50, 95 % CI (1·78, 3·51), Pfor interaction = 0·034). The empirical insulinemic potential for insulin resistance might have interactive effects with the rs2423279 polymorphism on the risk of CRC. The results of this study suggest the basis of the metabolic impact of the insulin response on colorectal carcinogenesis.

The Association of Empirical Dietary Index for Hyperinsulinemia with the Risk of Cancer and Cancer Mortality: A Meta-analysis of Observational Studies

This meta-analysis aimed to assess the association between the empirical dietary index for hyperinsulinemia (EDIH) and cancer mortality risk. We performed a comprehensive search across the online literature up to November 2022 databases. Then, hazard ratio (H.R.) and 95% confidence intervals (CI) were extracted. A total of 14 and seven cohort studies that reported H.R. for the risk of cancer incidence and cancer mortality respectively were included. The pooled H.R. (95% CI) of the association between EDIH and cancer incidence was 1.13 (1.05-1.23) in overall meta-analyses, 1.15 (1.08-1.22) in female subgroups, 1.27 (1.14-1.41) in digestive cancer subgroups, and 1.15 (1.07-1.24) in breast cancer subgroups. Also, the pooled H.R. (95% CI) of the association between EDIH and incidence of cancer mortality was 1.19 (1.13-1.26) in overall meta-analyses, 1.23 (1.13-1.34) in males, 1.18(1.10-1.28) in females, and 1.20 (1.13-1.27) in studies conducted on all cancers as an outcome. Our findings revealed that a higher EDIH was significantly associated with an increased risk of cancer incidence, particularly in females, digestive cancers, and breast cancer. Also, a higher EDIH score was related to a higher risk of cancer mortality overall in both male and female subgroups and with all cancers.

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.

Integrated multi-omics approach to distinct molecular characterization and classification of early-onset colorectal cancer

Incidence of early-onset colorectal cancer (EOCRC), defined by a diagnosed age under 50 years, is increasing, but its heterogeneous etiologies that differ from general CRC remain undetermined. We initially characterize the genome, epigenome, transcriptome, and proteome of tumors from 79 patients in a Chinese CRC cohort. Data for an additional 126 EOCRC subjects are obtained from the International Cancer Genome Consortium Chinese cohort and The Cancer Genome Atlas European cohort. We observe that early-onset tumors have a high tumor mutation burden; increased DNA repair features by mutational signature 3 and multi-layer pathway enrichments; strong perturbations at effects of DNA methylation and somatic copy-number alteration on gene expression; and upregulated immune infiltration as hot tumors underlying immunophenotypes. Notably, LMTK3 exhibits ancestral mutation disparity, potentially being a functional modulator and biomarker that drives molecular alterations in EOCRC development and immunotherapies. This integrative omics study provides valuable knowledge for precision oncology of CRC.

Risk factors for early-onset colorectal cancer: A large-scale Chinese cohort study

Background

The incidence of early-onset colorectal cancer (EOCRC) has increased globally since the early 1990s. Comprehensively examining the risk factors would be helpful for risk stratification and the development of personalized colorectal cancer screening strategies.

Methods

We performed a prospective study of the Chinese population aged 30-50 years to identify potential risk factors during a median follow-up of 9.1 years. We compared the distribution of demographic characteristics, lifestyle factors, dietary habits, and medical history among 222 EOCRC cases and 87,833 normal controls. Multivariate adjusted Cox hazard models were used for estimating EOCRC risks of each risk factor.

Results

Our final analyses indicated that participants with a higher body mass index (HR, 1.04; 95% CI:1.00,1.08), regular alcohol consumption (HR, 1.69; 95% CI: 1.12, 2.91), higher intake of fish (HR, 1.64; 95% CI: 1.01, 2.67), hypertension (HR, 1.99; 95% CI: 1.04, 3.81), diabetes (HR, 2.20; 95% CI: 1.08, 4.49), and first-degree relatives with cancer (HR, 1.70; 95% CI: 1.23, 2.36) were at higher risk of EOCRC.

Conclusion

We identified several modifiable as well as nonmodifiable risk factors, such as higher BMI, alcohol and fish consumption, hypertension, and diabetes, were associated with EOCRC.

High insulinemic potential of diet and lifestyle is associated with increased risk of chronic kidney disease incident in adults

BACKGROUND

The role of higher insulinemic effects of dietary pattern and lifestyle factors on the risk of chronic kidney disease (CKD) is not well-studied. In the current study, we aimed to investigate the relationship between the insulinemic potential of diet and lifestyle with the risk of CKD in adults.

METHODS

A total of 6044 individuals without CKD, aged>18 years, were recruited from among participants of the Tehran Lipid and Glucose Study (third and fourth surveys) and followed a mean of 6.03 years(follow-up rate:94.95%). The dietary intake data were collected using a food frequency questionnaire. The insulinemic potential of diet and lifestyle was determined based on four empirical indices, including the empirical dietary index for hyperinsulinemia (EDIH), the empirical dietary index for insulin resistance (EDIR), the empirical lifestyle index for hyperinsulinemia (ELIH), and the empirical lifestyle index for insulin resistance (ELIR).

RESULTS

Mean ± SD age of all study participants (54.3% women) was 37.8 ± 12.8 years. During the 6.03 years of follow-up (46,889.8 person-years), 1216(20.1%) new cases of CKD were identified. According to the multivariable-adjusted model, the risk of CKD incident is increased across quintiles of EDIR (OR = 1.29;95% CI: 1.06-1.57), ELIH (OR = 1.35; 95%CI: 1.10-1.67), and ELIR (OR = 1.24; 95%CI:1.02-1.51). However, no significant relationship was found between the EDIH score and the risk of CKD.

CONCLUSION

Results of the current study showed that dietary pattern with a high EDIR score and a lifestyle with higher ELIH and ELIR scores may be related to increasing the risk of CKD incident. However, no significant association was observed between EDIH score and CKD incident.

Risk factors for early-onset colorectal cancer: systematic review and meta-analysis

Background

The incidence of early-onset colorectal cancer (EOCRC), which means colorectal cancer diagnosed in patients under 50 years, has been increasing around the world. However, the etiology remains unclear. This study aims to identify risk factors for EOCRC.

Methods

This systematic review was conducted in PubMed, Embase, Scopus, and Cochrane Library databases from inception to November 25, 2022. We examined risk factors for EOCRC, including demographic factors, chronic conditions, and lifestyle behaviors or environmental factors. Random-effects/fixed-effects meta-analysis was adopted to combine effect estimates from published data. Study quality was evaluated with the Newcastle-Ottawa Scale (NOS). Statistical analysis was performed Revman5.3. Studies not suitable for the meta-analysis were analyzed by a systematic review.

Results

A total of 36 studies were identified for this review, and 30 studies were included in the meta-analysis. Significant risk factors for EOCRC included male (OR=1.20; 95% CI, 1.08-1.33), Caucasian (OR=1.44; 95% CI, 1.15-1.80), a family history of CRC (OR=5.90; 95% CI, 3.67-9.48), inflammatory bowel disease (OR=4.43; 95% CI, 4.05-4.84), obesity (OR=1.52; 95%CI, 1.20-1.91), overweight (OR=1.18; 95% CI, 1.12-1.25), triglycerides (OR=1.12; 95% CI, 1, 08-1.18), hypertension (OR=1.16; 95% CI, 1.12-1.21), metabolic syndrome (OR=1.29; 95% CI, 1.15-1.45), smoking (OR=1.44; 95% CI, 1.10-1.88), alcohol consumption (OR=1.41; 95% CI, 1.22-1.62), a sedentary lifestyle (OR=1.24; 95% CI, 1.05-1.46), red meat (OR=1.10; 95% CI, 1.04-1.16), processed meat (OR=1.53; 95% CI, 1.13-2.06), Western dietary patterns (OR=1.43; 95% CI, 1.18-1.73) and sugar-sweetened beverages (OR=1.55; 95% CI, 1.23-1.95). However, no statistical differences were found for hyperlipidemia and hyperglycemia. Vitamin D may be a protective factor (OR=0.72; 95% CI, 0.56-0.92). There was considerable heterogeneity among studies (I²>60%).

Conclusions

The study provides an overview of the etiology and risk factors of EOCRC. Current evidence can provide baseline data for risk prediction models specific to EOCRC and risk-tailored screening strategies.

Association of plant-based dietary patterns with the risk of colorectal cancer: a large-scale case-control study

Plant-based diets are associated with a lower risk of colorectal cancer, but the risk might differ by the quality of plant-based diets. This study aimed to investigate the association between different types of plant-based dietary patterns and colorectal cancer risk in the Chinese population. We conducted a case-control study with 2799 eligible colorectal cancer cases and 2799 sex- and age-matched controls in Guangzhou, China. A validated food frequency questionnaire was used to collect dietary data, from which we derived plant-based diet indices, including the plant-based diet index (PDI), the healthy PDI (hPDI), and the unhealthy PDI (uPDI). The PDI, hPDI, and uPDI assess the adherence to overall, healthy, and unhealthy plant-based dietary patterns, respectively. The odds ratios (ORs) and 95% confidence intervals (CIs) for colorectal cancer risk were estimated using unconditional logistic regression models. Higher adherence to the PDI, particularly the hPDI, was associated with a lower risk of colorectal cancer, whereas greater adherence to the uPDI was associated with a higher risk of colorectal cancer. Compared with the lowest quintile, the adjusted ORs in the highest quintile were 0.79 (95% CI: 0.66-0.95) for the PDI, 0.45 (95% CI: 0.38-0.55) for the hPDI, and 1.45 (95% CI: 1.18-1.78) for the hPDI, respectively. In stratified analysis, the inverse association between the PDI and colorectal cancer risk was not observed in women, and the positive association between the uPDI and colorectal cancer risk was not observed in men. In conclusion, these results support recommendations that shifting to a healthy plant-based dietary pattern is important for the prevention of colorectal cancer, particularly in the Chinese population that habitually consumes plant foods.

The global, regional, and national early-onset colorectal cancer burden and trends from 1990 to 2019: results from the Global Burden of Disease Study 2019

PURPOSE

The incidence of early-onset colorectal cancer (EO-CRC), which occurs in people under age 50, has been increasing annually. The aim of this study was to provide an up-to-date estimate of the global EO-CRC burden.

METHODS

We used Global Burden of Disease Study data and methodologies to describe changes in the EO-CRC burden from 1990 to 2019, including incidence, prevalence, mortality, and disability-adjusted life years (DALYs). The driving factors for cancer burden variation were further analyzed using decomposition analysis. Frontier analysis was used to visually demonstrate the potential for burden reduction in each country or region based on their development levels.

RESULTS

The global EO-CRC incidence more than doubled, increasing from 95,737 (95% uncertainty interval (UI): 90,838-101.042) /100,000 in 1990 to 226,782 (95% UI: 207,495-248,604) /100,000 in 2019. Additionally, related deaths increased from 50,997 (95% UI: 47,692-54,410) /100,000 to 87,014 (95% UI: 80,259-94,339) /100,000, and DALYs increased from 256,1842 (95% UI: 239,4962-2,735,823) /100,000 to 4,297,573 (95% UI: 3,965,485-4,650,790) /100,000. Regarding age-standardized rates, incidence and prevalence increased significantly, while mortality and DALYs rate were basically unchanged. Decomposition analysis showed a significant increase in DALYs in the middle sociodemographic index (SDI) quintile region, in which aging and population growth played a major driving role. Frontier analysis showed that countries or regions with a higher SDI quintile tend to have greater improvement potential.

CONCLUSION

The current EO-CRC burden was found to be the greatest in the high-middle SDI quintile region and East Asia, which may need to adjust screening guidelines accordingly and introduce more effective interventions.

Is early-onset cancer an emerging global epidemic? Current evidence and future implications

Over the past several decades, the incidence of early-onset cancers, often defined as cancers diagnosed in adults <50 years of age, in the breast, colorectum, endometrium, oesophagus, extrahepatic bile duct, gallbladder, head and neck, kidney, liver, bone marrow, pancreas, prostate, stomach and thyroid has increased in multiple countries. Increased use of screening programmes has contributed to this phenomenon to a certain extent, although a genuine increase in the incidence of early-onset forms of several cancer types also seems to have emerged. Evidence suggests an aetiological role of risk factor exposures in early life and young adulthood. Since the mid-20th century, substantial multigenerational changes in the exposome have occurred (including changes in diet, lifestyle, obesity, environment and the microbiome, all of which might interact with genomic and/or genetic susceptibilities). However, the effects of individual exposures remain largely unknown. To study early-life exposures and their implications for multiple cancer types will require prospective cohort studies with dedicated biobanking and data collection technologies. Raising awareness among both the public and health-care professionals will also be critical. In this Review, we describe changes in the incidence of early-onset cancers globally and suggest measures that are likely to reduce the burden of cancers and other chronic non-communicable diseases.

Postdiagnostic Inflammatory, Hyperinsulinemic, and Insulin-Resistant Diets and Lifestyles and the Risk of Prostate Cancer Progression and Mortality

BACKGROUND

Inflammatory and insulin pathways have been linked to prostate cancer; postdiagnostic behaviors activating these pathways may lead to poor outcomes. The empirical dietary inflammatory pattern (EDIP), empirical dietary index for hyperinsulinemia (EDIH), and empirical dietary index for insulin resistance (EDIR), and associated lifestyle indices (ELIH, ELIR) predict biomarkers of inflammation (EDIP: IL6, TNFaR2, CRP) and insulin secretion (EDIH/ELIH: c-peptide; EDIR/ELIR: TAG:HDL) from whole foods and behaviors.

METHODS

Associations of these indices with time to prostate cancer progression (primary, n = 2,056) and prostate cancer-specific mortality (PCSM; secondary, n = 2,447) were estimated among men diagnosed with nonmetastatic prostate cancer in the Cancer of the Prostate Strategic Urologic Research Endeavor cohort diet and lifestyle sub-study. Because the true (versus clinically documented) date of progression is unobserved, we used parametric (Weibull) survival models to accommodate interval-censoringand estimated adjusted HR and 95% confidence intervals (CI) for prostate cancer progression per 1-SD increase in index. Cox proportional hazards models were used to estimate PCSM associations.

RESULTS

During a median [interquartile range (IQR)] 6.4 years (IQR, 1.3-12.7), 192 progression and 73 PCSM events were observed. Inflammatory (EDIP: HR, 1.27; CI, 1.17-1.37), hyperinsulinemic (EDIH: HR, 1.24; CI, 1.05-1.46. ELIH: HR, 1.34; CI, 1.17-1.54), and insulin-resistant (EDIR: HR, 1.22; CI, 1.00-1.48. ELIR: HR, 1.36; CI, 1.12-1.64) indices were positively associated with risk of prostate cancer progression. There was no evidence of associations between the indices and PCSM.

CONCLUSIONS

Both inflammatory and insulinemic dietary and lifestyle patterns are associated with risk of prostate cancer progression.

IMPACT

For men with prostate cancer, consuming dietary patterns that limit chronic systemic inflammation and insulin hypersecretion may improve survivorship, especially when coupled with active lifestyle and healthy body weight. See related commentary by Kucuk, p. 1673.

Global, regional, and national burden of colorectal cancer and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Colorectal cancer is the third leading cause of cancer deaths worldwide. Given the recent increasing trends in colorectal cancer incidence globally, up-to-date information on the colorectal cancer burden could guide screening, early detection, and treatment strategies, and help effectively allocate resources. We examined the temporal patterns of the global, regional, and national burden of colorectal cancer and its risk factors in 204 countries and territories across the past three decades.

METHODS

Estimates of incidence, mortality, and disability-adjusted life years (DALYs) for colorectal cancer were generated as a part of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019 by age, sex, and geographical location for the period 1990-2019. Mortality estimates were produced using the cause of death ensemble model. We also calculated DALYs attributable to risk factors that had evidence of causation with colorectal cancer.

FINDINGS

Globally, between 1990 and 2019, colorectal cancer incident cases more than doubled, from 842 098 (95% uncertainty interval [UI] 810 408-868 574) to 2·17 million (2·00-2·34), and deaths increased from 518 126 (493 682-537 877) to 1·09 million (1·02-1·15). The global age-standardised incidence rate increased from 22·2 (95% UI 21·3-23·0) per 100 000 to 26·7 (24·6-28·9) per 100 000, whereas the age-standardised mortality rate decreased from 14·3 (13·5-14·9) per 100 000 to 13·7 (12·6-14·5) per 100 000 and the age-standardised DALY rate decreased from 308·5 (294·7-320·7) per 100 000 to 295·5 (275·2-313·0) per 100 000 from 1990 through 2019. Taiwan (province of China; 62·0 [48·9-80·0] per 100 000), Monaco (60·7 [48·5-73·6] per 100 000), and Andorra (56·6 [42·8-71·9] per 100 000) had the highest age-standardised incidence rates, while Greenland (31·4 [26·0-37·1] per 100 000), Brunei (30·3 [26·6-34·1] per 100 000), and Hungary (28·6 [23·6-34·0] per 100 000) had the highest age-standardised mortality rates. From 1990 through 2019, a substantial rise in incidence rates was observed in younger adults (age <50 years), particularly in high Socio-demographic Index (SDI) countries. Globally, a diet low in milk (15·6%), smoking (13·3%), a diet low in calcium (12·9%), and alcohol use (9·9%) were the main contributors to colorectal cancer DALYs in 2019.

INTERPRETATION

The increase in incidence rates in people younger than 50 years requires vigilance from researchers, clinicians, and policy makers and a possible reconsideration of screening guidelines. The fast-rising burden in low SDI and middle SDI countries in Asia and Africa calls for colorectal cancer prevention approaches, greater awareness, and cost-effective screening and therapeutic options in these regions.

FUNDING

Bill & Melinda Gates Foundation.

Diet as a Risk Factor for Early-Onset Colorectal Adenoma and Carcinoma: A Systematic Review

Background

Colorectal cancer in adults 50 years old and younger is increasing in incidence worldwide. Diet may be a modifiable risk factor. The objective of this study was to examine evidence regarding the association between diet and the risk of developing early-onset colorectal cancer (EOCRC) and early-onset colorectal adenomas in young adults.

Methods

PUBMED, Web of Science, and Embase were systematically searched for studies examining dietary intake as a risk factor for EOCRC and early-onset colorectal adenomas. Results were synthesized narratively due to the heterogeneity of the studies.

Results

Of the 415 studies identified, ten met the inclusion criteria. Of these ten studies, four provided data on dietary risk factors for early-onset colorectal adenomas and six provided data on dietary risk factors for EOCRC. The four studies that measured colorectal adenoma occurrence reported an increased incidence with high sugar sweetened beverage intake, a higher pro-inflammatory diet, a higher Western diet score and higher sulfur microbial diet score. A protective effect against early-onset colorectal adenomas was observed in those who had a higher Prudent diet score or higher adherence to other health dietary approaches (Dietary Approaches to Stop Hypertension, Alternative Healthy Eating Index-2010, or the alternative Mediterranean diet). Those who consumed large amounts of deep-fried foods, refined foods, followed a high fat diet, consumed large amounts of sugary drinks and desserts, and had low folate and fiber consumption had a significantly higher occurrence of EOCRC. A protective effect against EOCRC was observed for those who consumed more fruits and vegetables, high amounts of micronutrients and those who adhered to a vegetarian diet.

Conclusions

The results of this study reveal various dietary habits may be risk factors or protective against early-onset colorectal cancer and adenomas. Future research should focus on large prospective cohort studies with long-term follow-up to confirm published results and further examine whether differences in diet quality are associated with EOCRC risk.

Molecular Biologic and Epidemiologic Insights for Preventability of Colorectal Cancer

The etiology of colorectal cancer (CRC) has been informed from both a molecular biology perspective, which concerns the study of the nature, timing, and consequences of mutations in driver genes, and epidemiology, which focuses on identifying risk factors for cancer. For the most part, these fields have developed independently, and it is thus important to consider them in a more integrated manner. The molecular mutational perspective has stressed the importance of mutations due to replication of adult stem cells, and the molecular fingerprint of most CRCs does not suggest the importance of direct carcinogens. Epidemiology has identified numerous modifiable risk factors that account for most CRCs, most of which are not direct mutagens. The distribution of CRCs across the large bowel is not uniform, which is possibly caused by regional differences in the microbiota. Some risk factors are likely to act through or interact with the microbiota. The mutational perspective informs when risk factors may begin to operate in life and when they may cease to operate. Evidence from the mutational model and epidemiology supports that CRC risk factors begin early in life and may contribute to the risk of early-onset CRC. Later in carcinogenesis, there may be a "point of no return" when sufficient mutations have accumulated, and some risk factors do not affect cancer risk. This period may be at least 5-15 years for some risk factors. A more precise knowledge of timing of risk factor to cancer is required to inform preventive efforts.

Reproducibility and validity of diet quality scores derived from food-frequency questionnaires

BACKGROUND

Diet quality scores (DQSs) are frequently used to study diet-disease relations but the validity of these scores derived from FFQs has rarely been evaluated.

OBJECTIVES

To evaluate the validity and reproducibility of 6 commonly used DQSs derived from the FFQ, including the Alternate Healthy Eating Index-2010, Dietary Approaches to Stop Hypertension Trial score, alternative Mediterranean diet score, and 3 plant-based diet indices (overall, healthful, and unhealthful).

METHODS

This analysis included 1394 participants from the Men's Lifestyle Validation Study (N = 652) and the Women's Lifestyle Validation Study (N = 742). Participants completed a 152-item FFQ at the beginning of the study and 1 y later, as well as completed 2 weighed 7-d dietary records (7DDRs) and donated 2 blood samples 6 mo apart between FFQ assessments. The reproducibility of the FFQs was evaluated by rank intraclass correlation coefficients (ICCs). The validity was assessed by comparing FFQ-derived DQSs with those from the average of two 7DDRs using Spearman rank correlation coefficients deattenuated for random measurement error in the 7DDRs (rs). Furthermore, we calculated the correlations between DQSs and plasma biomarkers of diet, including fatty acids, folate, carotenoids, retinol, and α- and γ-tocopherol.

RESULTS

Six FFQ-derived DQSs demonstrated moderate to high reproducibility (energy-adjusted ICCs: 0.61-0.84) and validity (energy-adjusted, deattenuated rs = 0.56-0.80) in both men and women. We consistently observed expected correlations between FFQ-derived DQSs with plasma fatty acids, including long-chain n-3 (ω-3) and trans fatty acids, most carotenoids, and γ-tocopherol (rs > 0.2).

CONCLUSIONS

Our study demonstrates the validity of the FFQ to evaluate overall diet quality using 6 commonly used DQSs. In addition, these DQSs have qualitatively demonstrated biological relevance, as indicated by their correlations with circulating biomarkers.

Advances in Understanding Early-Onset Colorectal Cancer

Since the 1990s, the incidence of early-onset colorectal cancer (at <50 years of age) in the US has increased by more than 50%; similar increases have also been observed internationally. These increases are found particularly among individuals born during and after the 1960s, raising the possibility that the increased rates of early-onset colorectal cancer are attributable to changes in risk-factor patterns throughout successive generations. The reasons for these alarming epidemiologic patterns for early-onset colorectal cancer worldwide are only recently being investigated and major gaps in our knowledge remain. In the current issue of this journal, Arif and colleagues differentiated characteristics and outcomes of early-onset colorectal cancer in patients with the predisposing conditions of inflammatory bowel disease or hereditary genetic syndromes, compared with patients who have sporadic disease. Also, in this issue, Schumacher and colleagues investigated risk factors for early-onset colorectal adenocarcinoma in a nested case-control study among Kaiser Permanente Southern California (KPSC) health plan members. The research presented on characteristics and outcomes points to the importance of sporadic disease in the rise of early-onset colorectal cancer, while the research presented on risk factors points to the importance of obesity as a potential explanatory factor for this rise.See related articles by Arif et al., p. 1785 and by Schumacher et al., p. 1792.

Fusobacterium nucleatum Acts as a Pro-carcinogenic Bacterium in Colorectal Cancer: From Association to Causality

Colorectal cancer (CRC) is a common cancer worldwide with complex etiology. Fusobacterium nucleatum (F. nucleatum), an oral symbiotic bacterium, has been linked with CRC in the past decade. A series of gut microbiota studies show that CRC patients carry a high abundance of F. nucleatum in the tumor tissue and fecal, and etiological studies have clarified the role of F. nucleatum as a pro-carcinogenic bacterium in various stages of CRC. In this review, we summarize the biological characteristics of F. nucleatum and the epidemiological associations between F. nucleatum and CRC, and then highlight the mechanisms by which F. nucleatum participates in CRC progression, metastasis, and chemoresistance by affecting cancer cells or regulating the tumor microenvironment (TME). We also discuss the research gap in this field and give our perspective for future studies. These findings will pave the way for manipulating gut F. nucleatum to deal with CRC in the future.