Calcium intake and colon cancer risk subtypes by tumor molecular characteristics

Implication of calcium supplementations in health and diseases with special focus on colorectal cancer

Calcium is a fundamental and integrative element and helps to ensure optimal health by regulating various physiological and pathological processes. While there is substantiated evidence confirming the beneficial effects of calcium in the treatment, management, and prevention of various health conditions, including cancer, conflicting studies are imperative to acknowledge the potential negative role of calcium supplementation. The studies on calcium supplementation showed that a specific dose can help in the maintenance of good human health, and in the control of different types of diseases, including cancer. Calcium alone and when combined with vitamin D, emerges as a promising therapeutic option for efficiently managing cancer growth, when used with chemotherapy. Combination therapy is considered a more effective approach for treating advanced types of colorectal cancer. Nevertheless, several challenges drastically influence the treatment of cancer, such as individual discrepancy, drug resistance, and stage of cancer, among others. Henceforth, novel preventive, reliable therapeutic modalities are essential to control and reduce the incidence and mortality of colorectal cancer (CRC). The calcium-sensing receptor (CaSR) plays a pivotal role in calcium homeostasis, metabolism, and regulation of oncogenesis. Numerous studies have underscored the potential of CaSR, a G protein-coupled receptor, as a potential biomarker and target for colorectal cancer prevention and treatment. The multifaceted involvement of CaSR in anti-inflammatory and anti-carcinogenic processes paves the way for its utilization in the diagnosis and management of colorectal cancer. The current review highlights the important role of supplemental calcium in overall health and disease, along with the exploration of intricate mechanisms of CaSR pathways in the management and prevention of colorectal cancer.

Association between dietary factors and colorectal serrated polyps: a systematic review and meta-analysis

Background

Dietary factors may affect the incidence of colorectal serrated polyps (SP). However, its effects on SP are unclear as epidemiological studies on this topic have showed inconsistent results. The present systematic review and meta-analysis sought to evaluate the effects of dietary factors on SPs.

Methods

Studies regarding the association between dietary factors and SPs were identified by searching PubMed, Cochrane library, Embase and Chinese Biomedical Literature database from inception until 27 February 2023. Search terms include serrated, hyperplastic, adenoma, polyps, colorectal, rectal, rectum and risk. Heterogeneity was assessed using I2 statistics. The meta-analysis was conducted by using a random-effects model, and the pooled effects were expressed with odds ratios (OR) and 95% confidence intervals (95% CI). Probable sources of heterogeneity were identified through meta-regression. Subgroup analysis were based on lesion types, study designs, countries, and so on.

Results

28 studies were ultimately eligible after scanning, and five dietary factors including vitamin D, calcium, folate, fiber and red or processed meat were excerpted. Higher intakes of vitamin D (OR = 0.95, 95%CI:0.90-1.02), calcium (OR = 0.97, 95%CI: 0.91-1.03) and folate (OR = 0.82, 95% CI: 0.6-1.13) were not significantly associated with SP. Fiber intake (OR = 0.90, 95% CI: 0.82-0.99) was a protective factor against SPs. Red meat intake increased the risk of SPs by 30% for the highest versus lowest intakes (OR = 1.30, 95% CI: 1.13-1.51). For different lesion types, higher folate intake was associated with a decreased risk of HPs (OR = 0.59, 95%CI: 0.44-0.79), and higher vitamin D intake decreased the risk of SPs including SSA/P (OR = 0.93, 95%CI: 0.88-0.98).

Conclusions

Higher dietary fiber intake plays an effective role in preventing SP, while red meat intake is associated with an increased risk of SP. This evidence provides guidance for us to prevent SP from a dietary perspective.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?, RecordID=340750.

Preventive effects of 13 different drugs on colorectal cancer: a network meta-analysis

Introduction

The aim of the study was to evaluate the preventive effect of 13 drugs on colorectal cancer (CRC) and guide the clinical application of these drugs.

Material and methods

PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure were searched for randomized controlled trials (RCTs) and cohort studies. The Cochrane bias risk assessment tool and the Newcastle-Ottawa Scale quality evaluation tool were used to evaluate the quality of the included RCTs and cohort studies. The funnel plot was used to analyze publication bias. A network meta-analysis of the extracted data was conducted using Stata16.0 software.

Results

A total of 57 studies (34 RCTs and 23 cohort studies) involving 82719 participants were included. The network meta-analysis revealed that the quality of the included studies was good; the funnel plot showed no obvious publication bias. The network meta-analysis showed that the preventive effect of 13 drugs on CRC was better than that of the placebo. Allopurinol (SUCRA: 97.2%) was found to have the best effect, followed by berberine (SUCRA: 89.9%), non-aspirin NSAIDs (SUCRA: 84.5%), statins (SUCRA: 66.5%), metformin (SUCRA: 66.3%), calcium (SUCRA: 48.9%), mesalazine (SUCRA: 44.5%), ursodeoxycholic acid (SUCRA: 42.6%), vitamin D (SUCRA: 41.4%), mercaptopurine (SUCRA: 39.4%), aspirin (SUCRA: 30.4%), folic acid (SUCRA: 24.9%), and eicosapentaenoic acid (SUCRA: 16.3%).

Conclusions

The preventive effect of allopurinol on CRC was better than that of the other 13 drugs. These results can help doctors and patients understand the preventative effects of these drugs more intuitively and provide an evidence-based basis for the clinical application of these drugs.

The Contributions of Trace Elements on Molecular Subtype-Specific Colorectal Cancer

Purpose: Although growing studies have reported the disturbances of trace elements (TEs) homeostasis was closely associated with the occurrence of colorectal cancer (CRC), the clinical value of TEs in CRC with different molecular subtypes was largely unknown. This study aimed to explore the correlation between KRAS mutations/MSI status and serum TEs levels in patients with CRC. Methods: The serum concentrations of 18 TEs were detected by inductively coupled plasma emission spectrometry (ICP-MS). MSI status (two mononucleotides: BAT25, BAT26, three dinucleotides: D2S123, D5S346, and D17S250), KRAS (G516T, G517A, G518C, G520T, G521A, G522C, and G532A) mutations were detected by the multiplex fluorescent PCR and the real-time fluorescent quantitative PCR, respectively. The correlations among KRAS mutations/MSI status, demographic and clinical characteristics, and TEs were analyzed by Spearman correlation analysis. Results: The propensity score matching (PSM) analysis was adopted to minimize differences between groups. Before PSM, 204 CRC patients were recruited in this study, including 123 KRAS-negative patients and 81 KRAS-positive patients according to the test results of KRAS mutations, and 165 MSS patients and 39 MSI patients based on MSI detection. After PSM, the serum concentration of Mn was significantly lower in CRC patients with KRAS mutations than those without KRAS mutations, and a significant negative correlation was observed between Mn and Pb in the KRAS-positive cases. CRC patients carrying MSI had a significantly lower level of Rb compared to MSS patients. Importantly, Rb was significantly positively correlated with Fe, Mn, Se, and Zn in patients with MSI. Collectively, all our data indicated that the occurrence of different molecular events might be accompanied by different alterations in types and levels of serum TEs. Conclusions: CRC patients with different molecular subtypes presented different alterations in types and levels of serum TEs. Mn was significantly negatively correlated with the KRAS mutations, and Rb was noticeably negatively correlated with the MSI status, indicating certain TEs might contribute to the pathogenesis of molecular subtype-specific colorectal cancer.

Extra-skeletal effects of dietary calcium: Impact on the cardiovascular system, obesity, and cancer

Calcium is well known to be integral to bone and muscle health, with deleterious effects such as osteoporosis associated with inadequate calcium intake. Recent studies have also highlighted the significant effects of calcium in extra-musculoskeletal functioning, including the cardiovascular system, obesity, and cancer. Calcium impacts the cardiovascular system as an antagonist associated with a reduction in hypertension, increase vasodilation, and improvement in blood vessel function when obtained in the diet as an organic source, through food. However, the inorganic source of calcium, found in supplements, may be negatively associated with the cardiovascular system due to plaque deposits and atherogenesis when taken in excess. Some studies suggest that calcium intake may impact obesity by regulation of adipogenesis and reducing fat deposits with resulting weight loss. The pathogenesis of calcium for reducing obesity is thought to be related in part to its impact on gut microbiota profile, with the suggestion that calcium may have prebiotic properties. Animal and some human studies propose that calcium may also have a role in cancer prevention and/or treatment due to its function in the cell proliferation process and the impact on hormonal regulation, and thus warrants more investigations in the human population. Some prospective and small clinical studies suggest that calcium may be beneficial for colorectal cancer. Overall, emerging research in various areas continues to highlight the essentiality of dietary calcium for functioning at the molecular and biochemical level toward improvement in health and some chronic disease conditions.

Associations between nutritional factors and KRAS mutations in colorectal cancer: a systematic review

BACKGROUND

Between 30 and 50% of colon tumors have mutations in the Kirsten-ras (KRAS) gene, which have a large nutritional attributable risk. Despite its high frequency in colorectal cancer (CRC), data to support specific associations between KRAS mutations in CRC and diet are sparse. Here, we conducted a systematic review to summarize the current epidemiological evidence on the association between various dietary factors and KRAS mutations.

METHODS

PubMed, Science Direct, and Cochrane databases were searched for relevant studies published until December 31, 2019, using inclusion and exclusion criteria in accordance with PRISMA guidelines. We analyzed the studies to find associations between nutritional factors and CRC tumors with KRAS mutations in humans.

RESULTS

We identified 28 relevant studies to include in this systematic review. In-depth analyses showed unclear associations between nutritional factors and KRAS mutations in CRC. Most epidemiological studies in the same nutrient or food often reported conflicting and/or inconclusive findings, whereas for some dietary factors, the results were homogeneous.

CONCLUSIONS

Further research using a more robust prospective cohort study is needed to lend more credence to the epidemiological associations found between KRAS mutations and dietary factors.

Additively protective effects of vitamin D and calcium against colorectal adenoma incidence, malignant transformation and progression: A systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) exhibits a linear progression from normal colonic epithelium, adenoma initiation, carcinoma transformation and even to metastasis. Diet changes might influence carcinogenesis and prognosis. We aimed to determine the effects of vitamin D and calcium on colorectal adenoma incidence, malignancy development and prognosis.

METHODS

Systematic literature searches (PubMed, Embase, and Cochrane Library databases) and hand searches were performed by September 30, 2019. A random-effects model was adopted to pool relative ratios (RRs) for colorectal tumour incidence or hazard ratios (HRs) for CRC mortality. Stratified analyses were performed by gender, tumour location, calcium intake level and ethnic group.

RESULTS

Total 854,195 cases from 166 studies were included. The colorectal adenoma incidence was inversely correlated with the circulating 25-hydroxyvitamin D [25(OH)D] level (RR: 0.80, 95% CI: 0.71-0.89), vitamin D intake (RR: 0.87, 95% CI: 0.82-0.92) and calcium intake (RR: 0.86, 95% CI: 0.81-0.91). The CRC incidence was decreased by circulating 25(OH)D (RR: 0.67, 95% CI: 0.59-0.77), vitamin D intake (RR: 0.85, 95% CI: 0.78-0.93) and calcium intake (RR: 0.75, 95% CI: 0.70-0.79). High-level circulating 25(OH)D triggered better overall survival (HR: 0.67, 95% CI: 0.57-0.79) and CRC-specific survival (HR: 0.63, 95% CI: 0.53-0.74). Stratified analyses showed that vitamin D and calcium significantly suppressed colorectal tumour incidence among women. Left-sided CRC risk was reversely related to circulating 25(OH)D (RR: 0.60, 95% CI: 0.41-0.88) and vitamin D intake (RR: 0.73, 95% CI: 0.57-0.93). Circulating 25(OH)D decreased colorectal adenoma (RR: 0.63, 95% CI: 0.48-0.82) and CRC (RR: 0.69, 95% CI: 0.56-0.86) risk in populations with higher calcium intake. European and American populations benefited more from vitamin D intake against colorectal tumour. A significant dose-response relationship was observed between intake of vitamin D or calcium and colorectal tumour incidence.

CONCLUSIONS

Vitamin D and calcium play additively chemopreventive roles in colorectal adenoma incidence, malignant transformation and progression, especially for women and left-sided CRC patients.

Lifestyle and dietary environmental factors in colorectal cancer susceptibility

Colorectal cancer (CRC) incidence changes with time and by variations in diet and lifestyle, as evidenced historically by migrant studies and recently by extensive epidemiologic evidence. The worldwide heterogeneity in CRC incidence is strongly suggestive of etiological involvement of environmental exposures, particularly lifestyle and diet. It is established that physical inactivity, obesity and some dietary factors (red/processed meats, alcohol) are positively associated with CRC, while healthy lifestyle habits show inverse associations. Mechanistic evidence shows that lifestyle and dietary components that contribute to energy excess are linked with increased CRC via metabolic dysfunction, inflammation, oxidative stress, bacterial dysbiosis and breakdown of gut barrier integrity while the reverse is apparent for components associated with decreased risk. This chapter will review the available evidence on lifestyle and dietary factors in CRC etiology and their underlying mechanisms in CRC development. This short review will also touch upon available information on potential gene-environment interactions, molecular sub-types of CRC and anatomical sub-sites within the colorectum.