Systematic review and meta-analysis of diet quality and colorectal cancer risk: is the evidence of sufficient quality to develop recommendations?

Diet and physical activity advice for colorectal cancer survivors: critical synthesis of public-facing guidance

PURPOSE

Colorectal cancer (CRC) survivors report that diet and physical activity guidance from healthcare professionals following discharge from care is limited. Survivors seek advice from alternative sources. This study critically synthesised the English language diet and physical activity guidance available online for CRC survivors.

METHODS

We conducted an internet search to identify national cancer organisations (NCO) in countries with high CRC incidence rates. We searched NCO website content for guidance related to diet and physical activity. Recommendations were categorised by cancer phase (prevention/survivorship), cancer type, and the intended outcome (health or cancer-control-CRC recurrence/CRC-specific mortality). A synthesised guideline was derived from recommendations consistently made by at least half of the sources.

RESULTS

We identified 12 NCOs from six countries, by whom 27 diet and physical activity recommendations were made. For CRC prevention, over 80% of recommendations were aimed at improving cancer-control outcomes. For CRC survivorship, less than 40% of recommendations were aimed at improving cancer-control outcomes. Physical activity was the only recommendation present on more than 50% of NCO websites aimed at improving cancer-control outcomes for CRC survivorship.

CONCLUSION

Diet and physical activity guidance for CRC survivors on NCO websites is limited and primarily based on recommendations for improving general health, not improving cancer-control outcomes. NCO websites frequently refer survivors to primary prevention guidance, potentially reflecting the lack of evidence specific to CRC survivorship. There is a need for diet and physical activity advice for survivors that is evidence-based, comprehensive, and consistent across organisations and tailored to specific cancer sites.

Association between diet quality and ovarian cancer risk and survival

BACKGROUND

Research on diet quality and ovarian cancer is limited. We examined the association between diet quality and ovarian cancer risk and survival in a large prospective cohort.

METHODS

We used data from women in the prospective National Institutes of Health-AARP Diet and Health Study enrolled from 1995 to 1996 who were aged 50-71 years at baseline with follow-up through December 31, 2017. Participants completed a 124-item food frequency questionnaire at baseline, and diet quality was assessed via the Healthy Eating Index-2015, the alternate Mediterranean diet score, and the Dietary Approaches to Stop Hypertension score. Primary outcomes were first primary epithelial ovarian cancer diagnosis from cancer registry data and among those diagnosed with ovarian cancer all-cause mortality. We used a semi-Markov multistate model with Cox proportional hazards regression to account for semicompeting events.

RESULTS

Among 150 643 participants with a median follow-up time of 20.5 years, 1107 individuals were diagnosed with a first primary epithelial ovarian cancer. There was no evidence of an association between diet quality and ovarian cancer risk. Among those diagnosed with epithelial ovarian cancer, 893 deaths occurred with a median survival of 2.5 years. Better prediagnosis diet quality, according to the Healthy Eating Index-2015 (quintile 5 vs quintile 1: hazard ratio [HR] = 0.75, 95% confidence interval [CI] = 0.60 to 0.93) and alternate Mediterranean diet score (quintile 5 vs quintile 1: HR = 0.68, 95% CI = 0.53 to 0.87), was associated with lower all-cause mortality. There was no evidence of an association between Dietary Approaches to Stop Hypertension score and all-cause mortality.

CONCLUSIONS

Better prediagnosis diet quality was associated with lower all-cause mortality after ovarian cancer diagnosis but was not associated with ovarian cancer risk.

The association of the healthy eating index with risk of colorectal cancers (overall and by subsite) among Canadians

BACKGROUND

Healthy dietary patterns characterized by high intake of fruits and vegetables, grains/cereals, and lean meat/fish, and low intake of red/processed meats and refined carbohydrates, have been shown to be associated with reduced risk of colorectal cancer, but evidence regarding their association with colorectal cancer subsites is limited. Hence, this study was conducted to assess the association of a healthy dietary pattern, as reflected in the Healthy Eating Index (HEI) (a composite score based on consumption of various food groups), with risk of colorectal cancer, overall and by subsite.

METHODS

We conducted a case-cohort study in the Canadian Study of Diet, Lifestyle and Health (CSDLH). The study included all cases of incident colorectal cancer in the entire cohort, and an age-stratified subcohort of 3185 women and 2622 men. Cox regression models were used to estimate hazard ratios (HR) for the association between the HEI and the risk of colorectal cancer, overall and by subsite. We also assessed the association by sex and by selected metabolic factors.

RESULTS

For both sexes combined, the highest quintile of the HEI score was inversely associated with risk of colorectal cancer, colon cancer and proximal colon cancer (HR: 0.65; 95% CI: 0. 49-0.85, HR: 0.60, 95% CI: 0.44-0.83 and HR: 0.54, 95% CI: 0.35-0.85, respectively). However, these associations were mostly observed among men (HR: 0.56; 95% CI: 0.38-0.81, HR: 0.44, 95% CI: 0.28-0.69 and HR: 0.26; 95% CI: 0.12-0.56, for colorectal cancer, colon cancer and proximal colon cancer, respectively; p-interactions=0.029, 0.032 and 0.063, respectively). An inverse association was also observed between the HEI and risk of colorectal cancer among normal weight participants, overweight/obese participants, non-smokers, non-alcohol drinkers and participants who were physically inactive.

CONCLUSION

A healthy dietary pattern may reduce risk of colorectal cancer, particularly among men.

Dietary patterns and risk of colorectal cancer: a comparative analysis

BACKGROUND

Although several dietary patterns have been associated with incident colorectal cancer (CRC), it is unclear which diet is optimal.

METHODS

Participants included 48 409 men and 169 772 women from three USA-based prospective cohort studies. We compared the associations of 18 dietary patterns with CRC risk, including two reference scores. The reference scores were derived based on the dietary recommendations for cancer prevention and CRC-specific dietary risk factors mentioned in the 2018 World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) Third Expert Report. Multivariable Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Most dietary patterns showed moderate correlations with the WCRF dietary score (absolute values of Spearman correlation coefficients: 0.45-0.63), except the Plant-based diet index, low-carbohydrate diets, the Empirical dietary index for hyperinsulinemia (EDIH) and Empirical dietary inflammation pattern (EDIP). HR for the 10th-90th percentile difference in the score was 0.86 (95% CI: 0.78-0.94) for the Dietary Approaches to Stop Hypertension score (DASH), 1.15 (1.06-1.26) for Western dietary pattern, 1.20 (1.10-1.31) for EDIH and 1.23 (1.13-1.34) for EDIP. These associations between patterns and CRC risk persisted after adjusting for the two reference scores.

CONCLUSIONS

Although further research is needed to improve the WCRF/AICR dietary recommendations, our comprehensive assessment of dietary patterns revealed that the DASH, Western dietary pattern, EDIH and EDIP may be the most relevant diets for preventing CRC.

Identification of Key MicroRNAs and Genes between Colorectal Adenoma and Colorectal Cancer via Deep Learning on GEO Databases and Bioinformatics

Background

Deep learning techniques are gaining momentum in medical research. Colorectal adenoma (CRA) is a precancerous lesion that may develop into colorectal cancer (CRC) and its etiology and pathogenesis are unclear. This study aims to identify transcriptome differences between CRA and CRC via deep learning on Gene Expression Omnibus (GEO) databases and bioinformatics in the Chinese population.

Methods

In this study, three microarray datasets from the GEO database were used to identify the differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) in CRA and CRC. The FunRich software was performed to predict the targeted mRNAs of DEMs. The targeted mRNAs were overlapped with DEGs to determine the key DEGs. Molecular mechanisms of CRA and CRC were evaluated using enrichment analysis. Cytoscape was used to construct protein-protein interaction (PPI) and miRNA-mRNA regulatory networks. We analyzed the expression of key DEMs and DEGs, their prognosis, and correlation with immune infiltration based on the Kaplan-Meier plotter, UALCAN, and TIMER databases.

Results

A total of 38 DEGs are obtained after the intersection, including 11 upregulated genes and 27 downregulated genes. The DEGs were involved in the pathways, including epithelial-to-mesenchymal transition, sphingolipid metabolism, and intrinsic pathway for apoptosis. The expression of has-miR-34c (P = 0.036), hsa-miR-320a (P = 0.045), and has-miR-338 (P = 0.0063) was correlated with the prognosis of CRC patients. The expression levels of BCL2, PPM1L, ARHGAP44, and PRKACB in CRC tissues were significantly lower than normal tissues (P < 0.001), while the expression levels of TPD52L2 and WNK4 in CRC tissues were significantly higher than normal tissues (P < 0.01). These key genes are significantly associated with the immune infiltration of CRC.

Conclusion

This preliminary study will help identify patients with CRA and early CRC and establish prevention and monitoring strategies to reduce the incidence of CRC.

Diet quality indices and gastrointestinal cancer risk: results from the Lifelines study

Objective

To investigate the long-term association between four dietary quality indices and the risk of gastrointestinal (GI) cancer.

Methods

Baseline details of the dietary intake of participants, assessed by a single food frequency questionnaire from the prospective Lifelines population-based cohort were translated to diet quality scores using several dietary and dietary-lifestyle indices. Incident cases of GI cancer were then assessed by linkage to the Dutch nationwide histo-cytopathology registry. The association between GI cancer risk and diet quality (defined as higher quintiles on dietary indices compared to the first quintile) was assessed by multivariable Cox proportional hazard models.

Results

We included 72,695 participants aged 51.20 ± 8.71 years with a median follow-up to cancer diagnosis of 8 years (interquartile range 2 years). During follow-up, 434 colorectal cancers and 139 upper GI cancers were diagnosed. There was a significant reduction in colorectal cancer risk for high categories in the American Cancer Society (ACS) Index (hazard ratio 0.62; 95% CI 0.46–0.84). However, high dietary index scores were not associated with strong beneficial effects on upper GI cancer risk.

Conclusion

High quintiles on the ACS Index were associated with a significantly reduced risk of colorectal cancer. This index may be of use in a colorectal cancer prevention program.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02648-3.

Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.

Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.

Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.

Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.

Systematic Review Registration: CRD42021218361

Diet Quality of Malaysians across Lifespan: A Scoping Review of Evidence in a Multi-Ethnic Population

Malaysia is a rapidly developing economy experiencing a nutrition transition. It suffers from a double burden of over- and undernutrition, making it essential to understand diet quality in the population. In this scoping review, we have collated the existing literature on Malaysian diet quality, including factors that influence it, and the association between diet quality and health outcomes across the lifespan of Malaysians. Overall, diet quality was poor in all age groups studied. The Healthy Eating Index (HEI) and its iterations were predominantly used in urban and clinical settings to evaluate diet-chronic disease relationships. These indices were significantly associated with cardio-metabolic and disease risks in adults. The Diet Diversity Score (DDS) and Food Variety Score (FVS) were used to gauge diet quality in maternal and child nutrition studies and were associated with appropriate growth and caloric intake. Deficiencies were found in fruit, vegetable, legumes, and dairy intake. Meat, salt, and sugar intake were found to be excessive in many studies. The findings can inform policies to improve diet quality in this population. The review also identified knowledge gaps that require further investigation.

Implementing Curcumin in Translational Oncology Research

Most data published on curcumin and curcumin-based formulations are very promising. In cancer research, the majority of data has been obtained in vitro. Less frequently, researchers used experimental animals. The results of several clinical studies are conclusive, and these studies have established a good foundation for further research focusing on implementing curcumin in clinical oncology. However, the issues regarding timely data reporting and lack of disclosure of the exact curcumin formulations used in these studies should not be neglected. This article is a snapshot of the current status of publicly available data on curcumin clinical trials and a detailed presentation of results obtained so far with some curcumin formulations. Phenomena related to the observed effects of curcumin shown in clinical trials are presented, and its modifying effect on gut microbiota and metabolic reprogramming is discussed. Based on available data, there is a strong indication that curcumin and its metabolites present molecules that do not necessarily need to be abundant in order to act locally and benefit systemically. Future clinical studies should be designed in a way that will take that fact into consideration.

Analysis of 234 cases of colorectal polyps treated by endoscopic mucosal resection

BACKGROUND

Colorectal polyps refer to all neoplasms that protrude into the intestinal cavity. Researchers believe that 50%-70% of colorectal cancers originate from adenomatous polyps.

AIM

To investigate the endoscopic morphologic features, pathologic types, and clinical situation; evaluate the efficacy and safety of endoscopic mucosal resection (EMR); and guide clinicians in their daily practice.

METHODS

Two hundred thirty-four patients who underwent EMR in our hospital from January 1, 2018 to December 31, 2019 were recruited. Data including sex, age, endoscopic morphology of the polyps, and pathological characteristics were analyzed among groups.

RESULTS

A total of 295 polyps were resected from the 234 subjects enrolled in the study, of which 4 (1.36%) were Yamada type I. There were 75 (25.42%) type II, 101 (34.24%) type III, and 115 (38.98%) type IV adenomas. Among them, 41 were non-adenomas, 110 were low-risk adenomas, 139 were high-risk adenomas, and 5 were carcinomas. The differences in distribution were not statistically significant, with P values greater than 0.05. The risk of cancer significantly increased for polyps ≥ 1 cm in diameter (c² = 199.825, P = 0.00). Regarding the endoscopic morphological features, congestion, erosion, and lobulation were more common on the surface morphology of high-risk adenomas and cancerous polyps (c² = 75.257, P = 0.00), and most of them were Yamada types III and IV. In all, 6 of the 295 polyps could not be removed completely, with a one-time resection rate of 97.97%. There were two cases of postoperative bleeding and no cases of perforation, with an overall complication rate of 0.09%.

CONCLUSION

Colorectal polyps ranging from non-adenomatous polyps, low-risk adenomas, and high-risk adenomas to adenocarcinomas each has their own endoscopic features, while EMR, as a mature intervention, has good safety and operability and should be promoted clinically, especially at the primary care level.