Hereditary, environmental, and dietary risk factors of colorectal cancer: a case-control study in the Algerian East

Incidence and risk factors for colorectal cancer in Africa: a systematic review and meta-analysis

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. There is a significant burden of mortality from colorectal cancer in Africa. Due to the heterogeneity of dietary and lifestyle practices throughout Africa, our work sought to define risk factors for the development of CRC in the African continent.

METHODS

We systematically searched PubMed, Embase, Global Health, CINAHL, Cochrane CENTRAL, and African Index Medicus for studies written in English, examining the incidence and risk factors of CRC in Africa. A systematic analysis was done to compare different risk factors in constituent studies. A meta-analysis random effects model was fitted to estimate the pooled incidence of CRC.

RESULTS

Of 2471 studies screened, 26 were included for the quantitative analysis; 20 in the incidence analysis, and six in the risk factor analysis. The overall ASIR per 100,000 person-years of CRC for males and females was 7.51 and 6.22, respectively. The highest incidence rates were observed between 2012 and 2021. Risk factors for CRC in Africa include tobacco smoking, and consumption of red meat, butter, and alcohol. Protective factors included, regular consumption of fruits and regular physical activity.

CONCLUSION

The incidence of CRC in Africa is higher than that suggested by previous studies. Our study shows that nonmodifiable and modifiable factors contribute to CRC in Africa. High-quality studies conducted on generalizable populations that examine risk factors in a comprehensive fashion are required to inform primary and secondary prevention initiatives for CRC in Africa.

Causal roles of educational duration in bone mineral density and risk factors for osteoporosis: a Mendelian randomization study

BACKGROUND

Educational duration might play a vital role in preventing the occurrence and development of osteoporosis(OP).

PURPOSE

To assess the causal effect of educational duration on bone mineral density(BMD) and risk factors for OP by Mendelian randomization(MR) study.

METHODS

The causal relationship was analyzed using data from genome-wide association study(GWAS). Inverse variance weighting (IVW) was used as the main analysis method. Horizontal pleiotropy was identified by MR-Egger intercept test, MR pleiotropy residual sum and outlier (MR-PRESSO) test. The leave-one-out method was used as a sensitivity analysis.

RESULTS

The IVW results indicated that there was a positive causal relationship between educational duration and BMD (OR = 1.012, 95%CI:1.003-1.022), physical activity(PA) (OR = 1.156, 95%CI:1.032-1.295), calcium consumption (OR = 1.004, 95%CI:1.002-1.005), and coffee intake (OR = 1.019, 95%CI:1.014-1.024). There was a negative association between whole body fat mass (OR = 0.950, 95%CI:0.939-0.961), time for vigorous PA (OR = 0.955, 95%CI:0.939-0.972), sunbath (OR = 0.987, 95%CI:0.986-0.989), salt consumption (OR = 0.965, 95%CI:0.959-0.971), fizzy drink intake (OR = 0.985, 95%CI:0.978-0.992), smoking (OR = 0.969, 95%CI:0.964-0.975), and falling risk (OR = 0.976, 95%CI:0.965-0.987). There was no significant association between educational duration and lean mass, time for light-to-moderate PA, milk intake, and alcohol intake. Horizontal pleiotropy was absent in this study. The results were robust under sensitivity analyses.

CONCLUSION

A longer educational duration was causally linked with increased BMD. No causal relationship had been found between educational duration and lean mass, time for light-to-moderate PA, milk intake, and alcohol consumption as risk factors for osteoporosis.

Epidemiological insights into colorectal cancer in northwestern Algeria

Objectives

The incidence of colorectal cancer (CRC) has exhibited regional variability in North Africa and the Middle East, with a steady increase in Algeria. Despite this trend, limited data exist on the epidemiology of CRC in northwestern Algeria. Our study aimed to investigate the epidemiological characteristics of CRC in this region.

Methods

We conducted a retrospective study examining 255 confirmed CRC cases through medical records from patients at the Sidi Bel Abbes anti-cancer centre.

Results

The mean age of the study participants was 59 ± 13 years. The results showed a higher incidence in males (57%) than in females, and colon (62%) than rectal cancer. Within this cohort, 47% had a pre-existing medical condition, while 39% had a family history of cancer. Adenocarcinomas were the prevailing histological subtype in 94% of CRC cases. Compared with colon cancer, rectal cancer was less often diagnosed at stage IV of the disease (OR = 0.75; 95% CI = 0.09, 4.86; p = 0.8) and more likely in early-onset patients (OR = 2.27; 95% CI = 1.25, 4.17; p = 0.007). Men were at a higher risk of being diagnosed with metastatic CRC primarily hepatic metastases (OR = 2.03; 95% CI = 1.07, 3.99; p = 0.033) and pulmonary metastases (OR = 2.50; 95% CI = 1.07, 6.59; p = 0.045).

Conclusion

This study may provide a comprehensive glimpse into CRC epidemiology in northwest Algeria. Understanding regional differences is the key to implementing specific preventive and interventional strategies.

Prevalence and patterns of mutations in RAS/RAF/MEK/ERK/MAPK signaling pathway in colorectal cancer in North Africa

BACKGROUND

Our review discuss (i) the findings from analyzed data that have examined KRAS, NRAS and BRAF mutations in patients with colorectal cancer (CRC) in North Africa and to compare its prevalence with that shown in other populations and (ii) the possible role of dietary and lifestyle factors with CRC risk.  METHODS: Using electronic databases, a systematic literature search was performed for the KRAS, NRAS, and BRAF mutations in CRC patients from Morocco, Tunisia, Algeria and Lybia.  RESULTS: Seventeen studies were identified through electronic searches with six studies conducted in Morocco, eight in Tunisia, two in Algeria, and one in Libya. A total of 1843 CRC patients were included 576 (31.3%) in Morocco, 641 (34.8%) in Tunisia, 592 (32.1%) in Algeria, and 34 (1.8%) in Libya. Overall, the average age of patients was 52.7 years old. Patients were predominantly male (56.6%). The mutation rates of KRAS, NRAS and BRAF were 46.4%, 3.2% and 3.5% of all patients, respectively. A broad range of reported KRAS mutation frequencies have been reported in North Africa countries. The KRAS mutation frequency was 23.9% to 51% in Morocco, 23.1% to 68.2% in Tunisia, 31.4% to 50% in Algeria, and 38.2% in Libya. The G12D was the most frequently identified KRAS exon 2 mutations (31.6%), followed by G12V (25.4%), G13D (15.5%), G12C (10.2%), G12A (6.9%), and G12S (6.4%). G12R, G13V, G13C and G13R are less than 5%. There are important differences among North Africa countries. In Morocco and Tunisia, there is a higher prevalence of G12D mutation in KRAS exon 2 (≈50%). The most frequently mutation type in KRAS exon 3 was Q61L (40%). A59T and Q61E mutations were also found. In KRAS exon 4, the most common mutation was A146T (50%), followed by K117N (33.3%), A146P (8.3%) and A146V (8.3%).

CONCLUSION

KRAS mutated CRC patients in North Africa have been identified with incidence closer to the European figures. Beside established anti-CRC treatment, better understanding of the causality of CRC can be established by combining epidemiology and genetic/epigenetic on CRC etiology. This approach may be able to significantly reduce the burden of CRC in North Africa.

The first Middle East and North Africa expert consensus recommendations for the management of advanced colorectal cancer

Colorectal cancer (CRC) is ranked as the third most prevalent and the second deadliest cancer worldwide. In the Middle East and North Africa (MENA) region, the number of CRC cases increased over the past decades and will nearly double by 2030. The lack of clear MENA guidelines for the management of patients with CRC represents a step backwards in the fight against this burden. Therefore a panel of 24 MENA experts in the field of gastrointestinal oncology developed, using a Delphi process, the first consensus recommendations for the management of patients with advanced CRC. Forty-seven different statements were formulated in the areas of epidemiology, screening, biomarkers and treatment. These recommendations will guide, standardize and unify the management of this cancer in the MENA region.

Probiotics Interact With Lipids Metabolism and Affect Gut Health

Probiotics have attracted much attention due to their ability to modulate host intestinal microbe, participate in nutrient metabolism or immunomodulatory. Both inflammatory bowel disease (IBD) and bowel cancer are digestive system disease, which have become a global public health problem due to their unclear etiology, difficult to cure, and repeated attacks. Disturbed gut microbiota and abnormal lipid metabolism would increase the risk of intestinal inflammation. However, the link between lipid metabolism, probiotics, and IBD is unclear. In this review, we found that different lipids and their derivatives have different effects on IBD and gut microbes. ω-3 polyunsaturated fatty acids (PUFAs) docosahexaenoic acid, eicosapentaenoic acid, and their derivatives resolvin E1, resolvin D can inhibit oxidative stress and reactive oxygen species activate NFκB and MAPk pathway. While ω-6 PUFAs linoleic acid and arachidonic acid can be derived into leukotrienes and prostaglandins, which will aggravate IBD. Cholesterol can be converted into bile acids to promote lipid absorption and affect microbial survival and colonization. At the same time, it is affected by microbial bile salt hydrolase to regulate blood lipids. Low denstiy lipoprotein (LDL) is easily converted into oxidized LDL, thereby promoting inflammation, while high denstiy lipoprotein (HDL) has the opposite effect. Probiotics compete with intestinal microorganisms for nutrients or ecological sites and thus affect the structure of intestinal microbiota. Moreover, microbial short chain fatty acids, bile salt hydrolase, superoxide dismutase, glutathione, etc. can affect lipid metabolism and IBD. In conclusion, probiotics are directly or indirectly involved in lipids metabolism and their impact on IBD, which provides the possibility to explore the role of probiotics in improving gut health.

Higher Yogurt Consumption Is Associated With Lower Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis of Observational Studies

Background: Yogurt is known to be nutrient-rich and probiotic content, which gather optimism due to their potential role in preventing and managing cancers. The effect of yogurt consumption on colorectal cancer (CRC) is inconsistent.

Objective: This study aims to investigate the association of yogurt consumption with the risk of CRC.

Methods: Three databases, namely, PubMed, Web of Science, and Embase, were searched for all relevant studies from July 2021 on the association of yogurt consumption with CRC risk. We pooled the odds ratios (ORs) and their 95% CIs using a random-effects meta-analysis to assess the association.

Results: Finally, 16 studies met the inclusion criteria and were chosen in the meta-analysis. Yogurt consumption was significant with lower risk of CRC risk in the overall comparison (OR = 0.87, 95% CI: 0.81–0.94), in the cohort studies (OR = 0.91, 95% CI: 0.86–0.97), and case-control studies (OR = 0.75, 95% CI: 0.65–0.85). With regard to subgroup analyses by study region, cancer type, publication year, and sex, yogurt consumption significantly decreased overall CRC, colon cancer, and distal colon cancer risks. In stratified analyses, we observed significantly decreased CRC risk in Europe and Africa and published after 2010 and overall population. Sensitivity analysis indicated the result is stable and there is no publication bias in the meta-analysis.

Conclusions: Overall, this study indicated that yogurt intake was related to a decreased risk of CRC.

Polymorphism rs2682818 participates in the progression of colorectal carcinoma via miR-618-TIMP1 regulatory axis

Colorectal carcinoma (CRC) has a high morbidity and mortality. Current studies have confirmed a variety of microRNA polymorphisms were associated with tumor susceptibility, however, the mechanisms are still unknown. In this study, we were aimed to clarify how polymorphism rs2682818 participated in the progression of CRC. First of all, the differential expression of miR-618 was assessed by quantitative real-time polymerase chain reaction in CRC patients with different genotypes of polymorphism rs2682818, including homozygous (TT) genotype, homozygous (GG) genotype and heterozygous (TG) genotype. Secondly, plasmids carried miR-168 precursor sequences harboring rs2682818 (SNP type) or without rs2682818 (wild type) were transfected into 293T cells to verify that polymorphism rs2682818 affected miR-618 expression. Thirdly, CCK-8 assay, flow cytometry assay, transwell assay and mouse xenograft assay were performed to measure the biological functions of miR-618 in CRC. Fourthly, the candidate target genes of miR-618 which were predicted by bioinformatics tools were verified by luciferase reporter assay. Finally, in order to explain the potential molecular mechanisms, western blotting was performed to demonstrate the differential expression and phosphorylation of pathway related proteins. The results showed that miR-618 was down-regulated in colon cancer, especially in CRC patients with rs2682818 GG homozygous genotype. Higher expression of mature miR-618 occurred in patients with TT homozygous genotype, and these patients usually had a longer survival time. Moreover, miR-618 mimic obviously impaired the growth and invasion ability of CRC cells, and miR-618 mimic also remarkably promoted CRC cell apoptosis. Our luciferase experiments confirmed that TIMP1 was a target of miR-618 in CRC cells. Knockdown of TIMP1 also significantly inhibited the malignant cytological features of CRC, including malignant growth and invasion as well as apoptosis resistance. In summary, polymorphism rs2682818 participated in the progression of CRC via affecting the expression of mature miR-618 in CRC cells, and miR-618 inhibited the progression of CRC via targeting TIMP1expression.