Descriptive epidemiology of colorectal cancer in the United States, 1998-2001

The clinical relevance of microplastic exposure on colorectal cancer: A systematic review

Microplastic exposure can contaminate multiple organs through nasal, dermal, and respiratory routes. The effect of microplastic exposure on colorectal adenocarcinoma development has gained attention. This systematic review aimed to summarize studies of microplastic exposure in humans with colorectal cancer. The relevant studies were collected through a computer-assisted search in PubMed, ISI Web of Science, Embase, Scopus, and Google Scholar databases. A total of 747 documents were evaluated for eligibility by two independent authors. The quality assessment of eligible studies was evaluated by the JBI checklist, and required data were collected and extracted from the included studies. After analysis, four studies were found eligible. The microplastic infiltration in colorectal tissue biopsies was relatively high; polyamide, polycarbonate, and polypropylene polymers were among the most common polymers in colorectal tissue samples of patients with colorectal adenocarcinoma. The average particle size was 0.1 µm to 1.6 mm. Microplastics shape in colorectal cancerous tissue, including fibers, fragments, and films. Microplastic abundance in colorectal tumor tissue was 25.9-32.2 particles/g tissue. In the case-control study, the microplastic accumulation in colorectal cancer tissue samples was significantly higher than in controls. The etiology of colorectal cancer remains unclear; however, environmental factors are actively contributing to colorectal cancer development. While there are few studies on microplastics in patients with colorectal adenocarcinoma, existing evidence indicates microplastic accumulation in the colorectal tissue of these patients. Further research is needed to determine if microplastic exposure initiates or leads to the development of colorectal cancer events.

Gastrointestinal Malignancy: Genetic Implications to Clinical Applications

Advances in molecular genetics have revolutionized our understanding of the pathogenesis, progression, and therapeutic options for treating gastrointestinal (GI) cancers. This chapter provides a comprehensive overview of the molecular landscape of GI cancers, focusing on key genetic alterations implicated in tumorigenesis across various anatomical sites including GIST, colon and rectum, and pancreas. Emphasis is placed on critical oncogenic pathways, such as mutations in tumor suppressor genes, oncogenes, chromosomal instability, microsatellite instability, and epigenetic modifications. The role of molecular biomarkers in predicting prognosis, guiding treatment decisions, and monitoring therapeutic response is discussed, highlighting the integration of genomic profiling into clinical practice. Finally, we address the evolving landscape of precision oncology in GI cancers, considering targeted therapies and immunotherapies.

Prognostic Factors for Survival of Colorectal Adenocarcinoma Patients in Uganda

Background

In Uganda, similar to other countries in East Africa, the incidence of colorectal cancer (CRC) has been steadily increasing. This increase in incidence is accompanied by a poor prognosis. There is limited knowledge on factors responsible for the poor outcome of patients with CRC in Uganda. Cancer survival analysis is one way of determining some of these prognostic factors. The aim of this study was to determine prognostic factors associated with CRC survival in Ugandan patients.

Methods

This was a retroprospective cohort study involving patients with linked data in the Kampala cancer registry and medical records from hospitals in Uganda. Participants with a diagnosis of colorectal adenocarcinoma between 1st January 2008 and 31st December 2018 were included. Variables included patients’ demographic data, grade, stage and location of CRC, data on whether a patient was operated on, type of operation, treatment modalities and date of diagnosis. Our outcome variable was time to death after diagnosis. We computed and compared survival using the Log rank test and used Cox proportional hazards regression to determine factors associated with survival.

Results

A total of 247 patients were included in the study with a mean (SD) age of 53.3 (15.7) years and a female: male ratio of 1.14:1. The proportions of patients surviving at 1, 2 and 3 years were 65.2% (95% CI: 58.8–70.9), 42.0% (95% CI:35.6–48.3) and 33.3% (95% CI:27.3–39.4) respectively. In multivariate analysis, factors associated with increased mortality included clinical stage II (aHR = 2.44, 95% CI: 1.10–5.41, p=0.028), stage III (aHR=2.65, 95% CI: 1.31–5.39, p=0.007) and stage IV (aHR=5.47, 95% CI: 2.40–12.48, p<0.001). Curative surgery alone (aHR=0.63, 95% CI: 0.39–1.01, p=0.057) and curative surgery with chemotherapy (aHR=0.53, 95% CI: 0.32–0.88, p=0.015) were associated with a better survival.

Conclusion

The survival rate among CRC patients in Uganda is low. Advanced stage CRC accelerates mortality, while surgery alone or in combination with chemotherapy improves survival. Implementation of national screening programmes for early diagnosis of CRC and increasing surgery and oncology infrastructure is recommended to improve the CRC survival rate in the Ugandan population.

The interplay of pineal hormones and socioeconomic status leading to colorectal cancer disparity

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the United States. Despite increased screening options and state-of-art treatments offered in clinics, racial differences remain in CRC. African Americans (AAs) are disproportionately affected by the disease; the incidence and mortality are higher in AAs than Caucasian Americans (CAs). At the time of diagnosis, AAs more often present with advanced stages and aggressive CRCs, primarily accounting for the racial differences in therapeutic outcomes and mortality. The early incidence of CRC in AAs could be attributed to race-specific gene polymorphisms and lifestyle choices associated with socioeconomic status (SES). Altered melatonin-serotonin signaling, besides the established CRC risk factors (age, diet, obesity, alcoholism, and tobacco use), steered by SES, glucocorticoid, and Vitamin D status in AAs could also account for the early incidence in this racial group. This review focuses on how the lifestyle factors, diet, allelic variants, and altered expression of specific genes could lead to atypical serotonin and melatonin signaling by modulating the synthesis, secretion, and signaling of these pineal hormones in AAs and predisposing them to develop more aggressive CRC earlier than CAs. Crosstalk between gut microbiota and pineal hormones and its impact on CRC pathobiology is addressed from a race-specific perspective. Lastly, the status of melatonin-focused CRC treatments, the need to better understand the perturbed melatonin signaling, and the potential of pineal hormone-directed therapeutic interventions to reduce CRC-associated disparity are discussed.

The emerging role of super enhancer-derived noncoding RNAs in human cancer

Super enhancers (SEs) are large clusters of adjacent enhancers that drive the expression of genes which regulate cellular identity; SE regions can be enriched with a high density of transcription factors, co-factors, and enhancer-associated epigenetic modifications. Through enhanced activation of their target genes, SEs play an important role in various diseases and conditions, including cancer. Recent studies have shown that SEs not only activate the transcriptional expression of coding genes to directly regulate biological functions, but also drive the transcriptional expression of non-coding RNAs (ncRNAs) to indirectly regulate biological functions. SE-derived ncRNAs play critical roles in tumorigenesis, including malignant proliferation, metastasis, drug resistance, and inflammatory response. Moreover, the abnormal expression of SE-derived ncRNAs is closely related to the clinical and pathological characterization of tumors. In this review, we summarize the functions and roles of SE-derived ncRNAs in tumorigenesis and discuss their prospective applications in tumor therapy. A deeper understanding of the potential mechanism underlying the action of SE-derived ncRNAs in tumorigenesis may provide new strategies for the early diagnosis of tumors and targeted therapy.

The incidence and patterns of colorectal cancers in Sri Lanka from 2001 to 2010: Analysis of national cancer registry data

OBJECTIVES

The incidence of colorectal cancer (CRC) has been increasing in many Asian countries. This study aims to analyse trends in CRC incidence and histological patterns in Sri Lanka.

METHODS

All newly diagnosed patients with CRC in Sri Lanka during 2001-2010 included in the National Cancer Registry were analysed for trends in incidence using Joinpoint regression software.

RESULTS

A total of 7,694 CRC (male:female = 1.02:1, mean age = 58.7 years) were analysed. The incidence of CRC in Sri Lanka has increased from a WHO age-standardised rate of 2.9/100,000 in 2001 (95%-confidence interval [95%-CI]: 2.64-3.16) to 6.08/100,000 in 2010 (95%-CI: 5.71-6.44). This is an estimated annual percentage change (EAPC) of 8.9 (95%-CI: 7.5-10.4). The proportional increase in incidence was observed to be greater for females (2.8 to 5.6, EAPC: 9.4 (95%-CI: 7.7-11.2), p < .05) than males (3.02 to 6.62, EAPC: 8.5 (95%-CI: 6.9-10.2), p < .05).

CONCLUSIONS

Similar to other Asian countries, a significant increase in the incidence of CRC was observed in Sri Lanka. Rate of the increase may have been artificially inflated due to better case reporting and diagnostic scrutiny. Future studies focussing on trends in tumour stage and fatality will help shed light on changing patterns in the burden of CRC in Sri Lanka.

Genetic Variations of RAD51 and XRCC2 Genes Increase the Risk of Colorectal Cancer in Bangladeshi Population

OBJECTIVES

In case of Bangladeshi population, no report is observed till now showing the genetic variations of RAD51 (rs1801320) and XRCC2 (rs3218536) genes polymorphism having association with colorectal cancer risk. For this reason the aim of this study is to ascertain their interrelation with colorectal cancer occurrence in Bangladeshi population.

MATERIALS AND METHODS

A case control study was conducted where 200 colorectal cancer patients and 200 healthy volunteers were figured for this research using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

RESULTS

Here, in case of RAD51 (rs1801320), G/C heterozygous genotype was found significant (p=0.037; OR=1.64; 95% CI=1.03 to 2.6). On the other hand, G/G genotype was not found statistically significant (p=0.423; OR=1.61; 95% CI=0.49 to 5.22) and significance was observed for GC+GG (p=0.030; OR=1.63; 95% CI=1.05 to 2.55). In case of XRCC2 (rs3218536), C/T heterozygous genotype was remarked statistically significant (p=0.033; OR=1.60; 95% CI=1.04 to 2.46). The T/T genotype was not recorded statistically significant (p=0.237; OR=1.65; 95% CI=0.72 to 3.76) but significance found for CT+TT (p=0.027; OR=1.61; 95% CI=1.05 to 2.45). Moreover, it is found that the risk factor of developing CRC is observed in G/C, C/T heterozygote and GC+GG, CT+TT (heterozygote+ mutant) in RAD51 (rs1801320) and XRCC2 (rs3218536) respectively although no significance is observed in case of G/G and T/T mutant.

CONCLUSIONS

So, the association of RAD51 (rs1801320) and XRCC2 (rs3218536) genes polymorphism with colorectal cancer risk is observed in Bangladeshi population.

Screening and computational analysis of colorectal associated non-synonymous polymorphism in CTNNB1 gene in Pakistani population

Background

Colorectal cancer (CRC) is categorized by alteration of vital pathways such as β-catenin (CTNNB1) mutations, WNT signaling activation, tumor protein 53 (TP53) inactivation, BRAF, Adenomatous polyposis coli (APC) inactivation, KRAS, dysregulation of epithelial to mesenchymal transition (EMT) genes, MYC amplification, etc. In the present study an attempt was made to screen CTNNB1 gene in colorectal cancer samples from Pakistani population and investigated the association of CTNNB1 gene mutations in the development of colorectal cancer.

Methods

200 colorectal tumors approximately of male and female patients with sporadic or familial colorectal tumors and normal tissues were included. DNA was extracted and amplified through polymerase chain reaction (PCR) and subjected to exome sequence analysis. Immunohistochemistry was done to study protein expression. Molecular dynamic (MD) simulations of CTNNB1^WT and mutant S33F and T41A were performed to evaluate the stability, folding, conformational changes and dynamic behaviors of CTNNB1 protein.

Results

Sequence analysis revealed two activating mutations (S33F and T41A) in exon 3 of CTNNB1 gene involving the transition of C.T and A.G at amino acid position 33 and 41 respectively (p.C33T and p.A41G). Immuno-histochemical staining showed the accumulation of β-catenin protein both in cytoplasm as well as in the nuclei of cancer cells when compared with normal tissue. Further molecular modeling, docking and simulation approaches revealed significant conformational changes in the N-terminus region of normal to mutant CTNNB1 gene critical for binding with Glycogen synthase kinase 3-B (GSK3) and transducin containing protein1 (TrCp1).

Conclusion

Present study on Pakistani population revealed an association of two non-synonymous polymorphisms in the CTNNB1 gene with colorectal cancer. These genetic variants led to the accumulation of the CTNNB1, a hallmark of tumor development. Also, analysis of structure to function alterations in CTNNB1 gene is crucial in understanding downstream biological events.

2015 European Society of Coloproctology (ESCP) collaborating group. Patients with Crohn's disease have longer post-operative in-hospital stay than patients with colon cancer but no difference in complications' rate

BACKGROUND

Right hemicolectomy or ileocecal resection are used to treat benign conditions like Crohn's disease (CD) and malignant ones like colon cancer (CC).

AIM

To investigate differences in pre- and peri-operative factors and their impact on post-operative outcome in patients with CC and CD.

METHODS

This is a sub-group analysis of the European Society of Coloproctology's prospective, multi-centre snapshot audit. Adult patients with CC and CD undergoing right hemicolectomy or ileocecal resection were included. Primary outcome measure was 30-d post-operative complications. Secondary outcome measures were post-operative length of stay (LOS) at and readmission.

RESULTS

Three hundred and seventy-five patients with CD and 2,515 patients with CC were included. Patients with CD were younger (median = 37 years for CD and 71 years for CC (P < 0.01), had lower American Society of Anesthesiology score (ASA) grade (P < 0.01) and less comorbidity (P < 0.01), but were more likely to be current smokers (P < 0.01). Patients with CD were more frequently operated on by colorectal surgeons (P < 0.01) and frequently underwent ileocecal resection (P < 0.01) with higher rate of de-functioning/primary stoma construction (P < 0.01). Thirty-day post-operative mortality occurred exclusively in the CC group (66/2515, 2.3%). In multivariate analyses, the risk of post-operative complications was similar in the two groups (OR 0.80, 95%CI: 0.54-1.17; P = 0.25). Patients with CD had a significantly longer LOS (Geometric mean 0.87, 95%CI: 0.79-0.95; P < 0.01). There was no difference in re-admission rates. The audit did not collect data on post-operative enhanced recovery protocols that are implemented in the different participating centers.

CONCLUSION

Patients with CD were younger, with lower ASA grade, less comorbidity, operated on by experienced surgeons and underwent less radical resection but had a longer LOS than patients with CC although complications' rate was not different between the two groups.

High-Amylose Maize, Potato, and Butyrylated Starch Modulate Large Intestinal Fermentation, Microbial Composition, and Oncogenic miRNA Expression in Rats Fed A High-Protein Meat Diet

High red meat intake is associated with the risk of colorectal cancer (CRC), whereas dietary fibers, such as resistant starch (RS) seemed to protect against CRC. The aim of this study was to determine whether high-amylose potato starch (HAPS), high-amylose maize starch (HAMS), and butyrylated high-amylose maize starch (HAMSB)—produced by an organocatalytic route—could oppose the negative effects of a high-protein meat diet (HPM), in terms of fermentation pattern, cecal microbial composition, and colonic biomarkers of CRC. Rats were fed a HPM diet or an HPM diet where 10% of the maize starch was substituted with either HAPS, HAMS, or HAMSB, for 4 weeks. Feces, cecum digesta, and colonic tissue were obtained for biochemical, microbial, gene expression (oncogenic microRNA), and immuno-histochemical (O⁶-methyl-2-deoxyguanosine (O⁶MeG) adduct) analysis. The HAMS and HAMSB diets shifted the fecal fermentation pattern from protein towards carbohydrate metabolism. The HAMSB diet also substantially increased fecal butyrate concentration and the pool, compared with the other diets. All three RS treatments altered the cecal microbial composition in a diet specific manner. HAPS and HAMSB showed CRC preventive effects, based on the reduced colonic oncogenic miR17-92 cluster miRNA expression, but there was no significant diet-induced differences in the colonic O⁶MeG adduct levels. Overall, HAMSB consumption showed the most potential for limiting the negative effects of a high-meat diet.

Colorectal cancer survival rates in Ghana: A retrospective hospital-based study

Background

Colorectal cancer (CRC) is one of the commonest cancers associated with diverse prognosis times in different parts of the world. Despite medical interventions, the overall clinical outcomes and survival remains very poor for most patients in developing countries. This study therefore investigated the survival rate of colorectal cancer and its prognostic factors among patients at Komfo Anokye Teaching Hospital, Ghana.

Methodology

In this retrospective cohort study, a total of 221 patients diagnosed with CRC from 2009 to 2015 at the Surgical and Oncological units of Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana were employed. The survival graphs were obtained using the Kaplan–Meier method and compared by the Log-rank test. Cox regression analysis was used to assess prognostic factors. All analyses were performed by SPSS version 22.

Results

The median survival time was 15 months 95% CI (11.79–18.21). The overall survival rate for CRC over the 5 years period was 16.0%. The survival rates at the 1^st, 2^nd, 3^rd, 4^th and 5^th years were 64% 95% CI (56.2–71.1), 40% 95% CI (32.2–50.1), 21% 95% CI (11.4–30.6) 16% 95% CI (8.9–26.9) and 16% 95% CI (7.3–24.9). There was a significant difference in the survival rate of colorectal cancer according to the different stages (p = 0.0001). Family history [HR = (3.44), p = 0.029)], Chemotherapy [HR = (0.23), p = <0.0001)], BMI [HR = (1.78), p = 0.017)] and both chemo/radiotherapy (HR = (3.63), p = 0.042)] were the significant social and clinical factors influencing the overall survival. Pathological factors such as TNM tumour stage (p = 0.012), depth of tumour invasion (p = 0.036), lymph node metastasis (p = 0.0001), and distance metastasis (p = 0.001) were significantly associated with overall survival.

Conclusion

The study has clearly demonstrated that survival rate for CRC patients at KATH, Ghana is very low in a 5 years period. This is influenced by significant number of clinical and pathological prognostic factors. Identification of prognostic factors would be a primary basis for early prediction and treatment of patients with colorectal cancer.

Different Oat Ingredients Stimulate Specific Microbial Metabolites in the Gut Microbiome of Three Human Individuals in Vitro

We used a standardized in vitro simulation of the intestinal environment of three human donors to investigate the effect of six oat ingredients, which were produced by the application of different processing techniques, on the gut microbial community. Fructooligosaccharide was used as the positive control. Consistent changes in pH and gas production, on average -0.4 pH units and +32 kPa, indicated the high fermentability of the oat ingredients, and the resulting increased production of metabolites that are considered as beneficial for human health. These metabolites included acetate and lactate, but mostly propionate (+13.6 mM on average). All oat ingredients resulted in increased bifidobacteria levels with an average increase of 0.73 log. Moreover, a decreased production of proteolytic markers was observed, including branched short-chain fatty acids and ammonium. The results were donor-specific and product-specific. The results suggested an association between the total amounts of dietary fiber and the prebiotic potentials of different ingredients. Furthermore, as mechanical processing of oat products has previously been linked to increased extractability of dietary fibers, the obtained results suggest that different processing techniques might have impacted the potential functional properties of the final ingredients.

CCNA2 acts as a novel biomarker in regulating the growth and apoptosis of colorectal cancer

OBJECTIVE

Colorectal cancer (CRC) is considered to be the most prevalent malignant tumors that contribute to high cancer-related mortality. However, the signaling pathways involved in CRC and CRC-driven genes are largely unknown. We seek to discover a novel biomarker in CRC.

MATERIALS AND METHODS

All clinical CRC samples (n=33) were from Xiangya Hospital. We first selected CCNA2 by integrated bioinformatics analysis of four GSE databases. Next, the expression of CCNA2 in tissues and cell lines was verified by quantitative real-time PCR. The effects of CCNA2 on cell growth, proliferation, cell cycle, and apoptosis were examined by in vitro assays.

RESULTS

We identified 498 shared DEGs (294 upregulated and 204 downregulated), and the top ten hub genes were selected by integrated analysis. These hub genes were significantly overexpressed in CRC samples and were positively correlated. Our data revealed that the expression of CCNA2 in CRC tissues is higher than that in normal tissues. The CCNA2 knockdown could significantly suppress CRC cell growth by impairing cell cycle progression and inducing cell apoptosis.

CONCLUSION

CCNA2, as a novel oncogenic gene, plays a role in regulating cancer cell growth and apoptosis. It could be used as a new biomarker for diagnosis and therapy in CRC.

The expression of telomere-related proteins and DNA damage response and their association with telomere length in colorectal cancer in Saudi patients

Background

Colorectal cancer is the leading cause of cancer-related deaths in Saudi Arabia. Cancer has a multifactorial nature and can be described as a disease of altered gene expression. The profiling of gene expression has been used to identify cancer subtypes and to predict patients’ responsiveness. Telomere-associated proteins that regulate telomere biology are essential molecules in cancer development. Thus, the present study examined their contributions to colorectal cancer progression in Saudi patients.

Methods

The expression of hTERT, TRF1, TRF2, POT1, ATR, ATM, Chk1 and Chk2 were measured via real-time PCR in matched cancerous and adjacent tissues of CRC patients. The protein level of hTERT, TRF1, TRF2, ATR, ATM, Chk1 and Chk2 were measured using immunohistochemistry. A region of hTERT core promoter was sequenced via Sanger sequencing. Methylation of CTCF binding site was examined via methylation-specific PCR. Finally, the length of telomere was estimated using q-PCR.

Results

Our results showed that POT1, ATR, Chk1 and Chk2 show increased expression in CRC relative to the adjacent mucosa. The expression levels of each gene were associated with clinicopathological characteristics of patients with CRC. There was a positive correlation between the age of the patients and hTERT expression. Regarding tumor site, telomere length, ATR, ATM and Chk1 were shown to be altered. No somatic mutation was detected in hTERT core promoter, and no differences in methylation patterns at CTCF binding site in the promoter between normal and cancer tissues.

Conclusion

Analysis of targeted genes expression in colorectal cancer based on the clinical variables revealed that tumor location and age could have a role in gene expression and telomere length variations and this could be taken under consideration during CRC diagnosis and therapy. Other epigenetic mechanisms could influence hTERT expression in cancers. Our findings warrant further validation through experiments involving a larger number of patients.

Arabinoxylo-Oligosaccharides and Inulin Impact Inter-Individual Variation on Microbial Metabolism and Composition, Which Immunomodulates Human Cells

Fecal batch fermentations coupled to cocultures of epithelial cells and macrophages were used to compare how arabinoxylo-oligosaccharides (AXOS) and inulin modulate gut microbial activity and composition of three different human donors and subsequently the epithelial permeability and immune response. Both inulin and AXOS decreased the pH during incubation (-1.5 pH units), leading to increased productions of acetate, propionate, and butyrate. Differences in terms of metabolites production could be linked to specific microbial alterations at genus level upon inulin/AXOS supplementation (i.e., Bifidobacterium, Bacteroides, Prevotella and unclassified Erysipelotrichaceae), as shown by 16S-targeted Illumina sequencing. Both products stimulated gut barrier and immune function with increases in TEER, NF-KB, IL-10, and IL-6. Ingredients with different structures selectively modulate the microbiota of a specific donor leading to differential changes at metabolic level. The extent of this effect is donor specific and is linked to a final specific modulation of the host's immune system.

Evaluation of Colorectal Cancer Incidence Trends in the United States (2000-2014)

Colorectal cancer (CRC) incidence rates have declined in recent years for people of all races/ethnicities; however, the extent to which the decrease varies annually by demographic and disease-related characteristics is largely unknown. This study examines trends and annual percent change (APC) in the incidence among persons diagnosed with CRC in the United States of America from 2000-2014. The data obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program were analyzed, and all persons (N = 577,708) with malignant CRC recorded in the SEER 18 database from 2000 to 2014 were characterized according to sex, race, age at diagnosis, disease site and stage. Incidence rates and APC were calculated for the entire study period. Overall, the incidence rate of CRC decreased from 54.5 in 2000 to 38.6 per 100,000 in 2014, with APC = -2.66 (p < 0.0001). Decline in rates was most profound between 2008 and 2011 from 46.0 to 40.7 per 100,000 (APC = -4.04; p < 0.0001). Rates were higher for males (vs. females; rate ratio (RR) = 1.33) and for blacks (vs. whites; RR = 1.23). Proximal colon cancers at the localized stage were the predominant cancers. An increase in rate was observed among people younger than 50 years (6.6 per 100,000, APC= 1.5). The annual rate of CRC has decreased over time. However, the development and implementation of interventions that further reduce the disparities among demographic and disease-related subgroups are warranted.

Anthocyanins/anthocyanidins and colorectal cancer: What is behind the scenes?

Colorectal cancer (CRC) is one of the most common cause of cancer death. Phytochemicals, especially anthocyanins/anthocyanidins (A/A), have gathered attention of the scientific community owing to their anti-inflammatory, antioxidant, and cancer-inhibitory properties. In this review, we discussed the possible mechanisms whereby A/A exhibit intestinal anticarcinogenic characteristics. Anthocyanins/anthocyanidins inhibit the pro-inflammatory NF-κB pathway, attenuate Wnt signaling and suppress abnormal epithelial cell proliferation. In addition, A/A induce mitochondrial-mediated apoptosis and downregulate Akt/mTOR (mammalian target of rapamycin) pathway. Furthermore, activation of AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) also contributes to the anti-carcinogenic effects of A/A. Finally, downregulation of metalloproteinases (MMPs) by A/A inhibits tumor invasion and metastasis. In conclusion, A/A exert their anti-tumor effects against colorectal carcinogenesis via multiple mechanisms, providing insights into the use of A/A as a natural chemopreventive intervention on major colorectal carcinogenesis.

Dual roles of yes-associated protein (YAP) in colorectal cancer

Yes-associated protein (YAP) is a downstream effector molecule of a newly emerging tumour suppressor pathway called the Hippo pathway. YAP is a transcriptional co-activator and mis-expressed in various cancers, including colorectal cancer (CRC). Accumulating studies show that the high expression of nuclear YAP is linked with tumour progression and decreased survival. Nuclear YAP can interact with other transcription factors to promote cancer cell proliferation, apoptosis, metastasis and maintenance of stemness. Therefore, YAP has the potential to be a tumour biomarker or therapeutic target for CRC. However, recently, a number of studies have supported a contradictory role for YAP as a tumour suppressor, demonstrating inhibition of the tumorigenesis of CRC, involvement in promoting cell apoptosis, and inhibiting the maintenance of intestinal stem cells and inflammatory activity. In these studies, high expression of YAP was highly correlated with worse survival in CRC. In this review, we will comprehensively summarize and analyse these paradoxical reports, and discuss both the oncogenic and tumour suppressor functions of YAP in the differential status of CRC progression. Further investigation into the mechanisms responsible for the dual function of YAP will be of great value in the prevention, early diagnosis, and therapy of CRC.

Mismatch Repair Proteins Initiate Epigenetic Alterations during Inflammation-Driven Tumorigenesis

Aberrant silencing of genes by DNA methylation contributes to cancer, yet how this process is initiated remains unclear. Using a murine model of inflammation-induced tumorigenesis, we tested the hypothesis that inflammation promotes recruitment of epigenetic proteins to chromatin, initiating methylation and gene silencing in tumors. Compared with normal epithelium and noninflammation-induced tumors, inflammation-induced tumors gained DNA methylation at CpG islands, some of which are associated with putative tumor suppressor genes. Hypermethylated genes exhibited enrichment of repressive chromatin marks and reduced expression prior to tumorigenesis, at a time point coinciding with peak levels of inflammation-associated DNA damage. Loss of MutS homolog 2 (MSH2), a mismatch repair (MMR) protein, abrogated early inflammation-induced epigenetic alterations and DNA hypermethylation alterations observed in inflammation-induced tumors. These results indicate that early epigenetic alterations initiated by inflammation and MMR proteins lead to gene silencing during tumorigenesis, revealing a novel mechanism of epigenetic alterations in inflammation-driven cancer. Understanding such mechanisms will inform development of pharmacotherapies to reduce carcinogenesis. Cancer Res; 77(13); 3467-78. ©2017 AACR.

The microbial fermentation characteristics depend on both carbohydrate source and heat processing: a model experiment with ileo-cannulated pigs

The effects of carbohydrate (CHO) source and processing (extrusion cooking) on large intestinal fermentation products were studied in ileo-cannulated pigs as a model for humans. Pigs were fed diets containing barley, pea or a mixture of potato starch:wheat bran (PSWB) either raw or extrusion cooked. Extrusion cooking reduced the amount of starch fermented in the large intestine by 52-96% depending on the CHO source and the total pool of butyrate in the distal small intestine + large intestine by on average 60% across diets. Overall, extrusion cooking caused a shift in the composition of short-chain fatty acids (SCFA) produced towards more acetate and less propionate and butyrate. The CHO source and processing highly affected the fermentation characteristics and extrusion cooking generally reduced large intestinal fermentation and resulted in a less desirable composition of the fermentation products. The latter outcome is non-conducive to a healthy large intestinal environment and its resulting metabolic health.

Colonic Polyps: Diagnosis and Surveillance

Colorectal cancer begins as a polyp that is a benign growth on the mucosal surface of the colon or rectum. Over a period of 5 to 15 years, polyps can degenerate into a cancer, thus invading the colonic wall. Colorectal screening methods are designed to diagnose and remove polyps before they acquire invasive potential and develop into cancer. Screening for colorectal cancer can prevent and reduce mortality. Given the benefits and effectiveness of screening, guidelines exist from multiple organizations. These guidelines risk-stratify patients to determine the age of screening initiation and the interval for repeat screening. Categories of colorectal cancer risk include average risk, increased risk, and high risk based on individual and family medical history. Screening methods vary widely in the ability to diagnose and treat polyps and in the degree of invasiveness or risk of complication to the patient. Colonoscopy is held as the "gold standard" by which all other methods are compared; however, less-invasive modalities including computed tomographic colonography are increasing in popularity.

How generalizable are the SEER registries to the cancer populations of the USA?

BACKGROUND

We determined whether the current SEER registries are representative of the nation's cancer cases or the socio-demographic characteristics.

METHODS

We used breast cancer (BC) and colorectal cancer (CRC) cases diagnosed 2004-2009 from the US Cancer Statistics (USCS) database. Cases were classified into groups residing in SEER coverage areas and the other areas. We compared difference between SEER and non-SEER areas in: age-race-specific proportions of late-stage BC or CRC, area demographics and socioeconomic factors, and data quality.

RESULTS

For late-stage CRC diagnosis, SEER areas contained lower proportions of people with other race and higher proportions of Asian and Hispanic females aged <40, than non-SEER areas. For late-stage BC diagnosis, SEER and non-SEER estimates were comparable. SEER areas had lower percentages of whites and higher percentages of young people, were more urban, and had higher percentage of poor, lower educational attainment, and higher unemployment. SEER areas also tended to have a higher percentage of case completeness than non-SEER areas.

CONCLUSION

Overall, SEER registries were not significantly different from non-SEER areas in terms of average age-race-specific proportions of late-stage BC or CRC, except for estimates of late-stage CRC for other race and young Asian and Hispanic women. Although case completeness was better in SEER areas than non-SEER areas, SEER areas had greater economic disadvantage and greater minority diversity among the population. This study demonstrated a need for caution in using SEER data and discussed advantages of using the more complete USCS database.

Colorectal Carcinomas in Uyo City, Southern Geopolitical Zone of Nigeria: A Review of Clinicopathological Characteristics and Literature

Colorectal carcinomas (CRC) were initially thought to be rare in Africa including Nigeria, but recent studies have shown a reverse trend in our environment. This study is aimed to identify the clinical and pathological characteristics of CRC diagnosed between July 2006 and June 2015 in the University of Uyo Teaching Hospital, and a Private Specialist Laboratory, Uyo, Akwa Ibom State, Nigeria. All histological diagnosed cases of CRC seen in the two laboratories (University teaching and a private facility) in Uyo, Akwa-Ibom state, Nigeria during the study period were retrieved noting their bio-data, pathological and clinical variables. A total of 45 patients of age range 26-80 years with a mean of 55.9 years (SD 3.9) and a male to female ratio of 1.4:1 were seen. The two most common age groups affected in CRCs were 61-70 years (28.9%) and 51-60 years (24.4%) respectively. Majority of CRC patients were older than 40 years (86.7%) with identifiable predisposing factors being tubulo-villous adenoma (4 cases, 8.8%), villous adenoma (2 cases 4.4%), polyposis syndromes (2 cases, 4.4%) and schistosomiasis (1 case, 2.2%). Features of large intestinal obstruction were the most common presenting symptom of CRC (53.3%). Rectal bleeding, alteration in bowel habit and fecal incontinence were other symptoms, accounting for 33.3%, 8.9% and 4.4% of cases respectively. Left-sided CRCs were commoner (68.9%) with the majority appearing as annular-constricting type macroscopically (60.0%). Recto-sigmoid region was the preponderant site involved in CRC (29 cases, 64.5%). Adenocarcinoma (84.4%) was the most frequent histological subtype. Mucinous carcinoma, signet ring carcinoma and carcinoid tumor were other histologic subtypes seen in 8.9, 4.4 and 2.2% of cases respectively. The 22.0% of CRC patients presented at advanced stages of the disease. It can be concluded that majority of CRC patients were older than 40 years (86.7%) with features of intestinal obstruction (53.3%) and adenocarcinoma (84.4%) being the predominant mode of clinical presentation and histological subtype respectively.

Worldwide burden of colorectal cancer: a review

Colorectal cancer is a major public health problem, being the third most commonly diagnosed cancer and the fourth cause of cancer death worldwide. There is wide variation over time among the different geographic areas due to variable exposure to risk factors, introduction and uptake of screening as well as access to appropriate treatment services. Indeed, a large proportion of the disparities may be attributed to socioeconomic status. Although colorectal cancer continues to be a disease of the developed world, incidence rates have been rising in developing countries. Moreover, the global burden is expected to further increase due to the growth and aging of the population and because of the adoption of westernized behaviors and lifestyle. Colorectal cancer screening has been proven to greatly reduce mortality rates that have declined in many longstanding as well as newly economically developed countries. Statistics on colorectal cancer occurrence are essential to develop targeted strategies that could alleviate the burden of the disease. The aim of this paper is to provide a review of incidence, mortality and survival rates for colorectal cancer as well as their geographic variations and temporal trends.

Impact of multicellular tumor spheroids as an in vivo‑like tumor model on anticancer drug response

The incidence of colorectal cancer is higher in men than in women, amounting to 15% of cancer-related diseases as a whole. As such, undesirable effects, arising from the administration of current chemotherapeutic agents (the FOLFIRI/FOLFOX combinations), which are exerted on the remaining non-cancerous tissues and/or cells, have contributed to the occurrence of resistance to multiple drugs, thus markedly reducing their efficacy. However, the delivery of chemotherapeutic agents may be improved and their action may be more selectively targeted to diseased tissues/cells by means of developing biotechnologies and nano-techniques. Thus, the current focus is on creating biological tissue and related tumor models, by means of three-dimensional (3D) spheres, in an attempt to bridge the gap between results obtained in the pre-clinical phase and promising outcomes obtained in clinical trials. For this purpose, the characterization and use of so-called ‘multicellular tumor spheroids’, may prove to be invaluable. In this study, we focus on describing the efficacy of a model 3D system as compared to the traditional 2D tumor spheres in determining drug response, highlighting a potentially greater effect of the drugs following the encapsulation of respective liposomes. The results obtained demonstrate the successful preparation of a suspension of liposomes loaded with folinic acid, oxaliplatin and 5-fluorouracil (5-FU), and loaded with meso-tetra (4-sulfonatophenyl) porphyrin. Following its use on HT-29 colorectal cancer cells, an important comparative reduction was noted in the viability of the HT-29 cells, demonstrating the efficacy of multicellular tumor spheroids carrying liposomes loaded with therapeutic drugs. These findings indicate that the method of drug encapsulation in liposomes may improve the treatment efficacy of chemotherapeutic agents.

Multistage vector delivery of sulindac and silymarin for prevention of colon cancer

Familial adenomatous polyposis (FAP) is an inherited condition secondary to germline mutations in the APC gene, thus resulting in the formation of hundreds of colonic adenomas that eventually progress into colon cancer. Surgical removal of the colon remains the only treatment option to avoid malignancy, as long-term exposure to chemopreventive agents such as sulindac (a non-steroidal anti-inflammatory drug) and silymarin (phytoestrogen) is not feasible. Here, we have developed a multistage silicon-based drug delivery platform for sulindac and silymarin that preferentially interacts with colon cancer cells as opposed to normal intestinal mucosa. Preferential binding and internalization of these drugs into colon cancer cells was obtained using a targeting strategy against the protein meprin A, which we demonstrate is overexpressed in human colon cancer cells and in the small intestine of Apc(Min/+) mice. We propose that this delivery system could potentially be used to reduce drug-induced side effects in FAP patients, thus enabling long-term prevention of adenoma formation.

Trends in colorectal cancer admissions and stage at presentation: impact of screening

BACKGROUND

Colorectal cancer (CRC) incidence is rising among patients under age 50. As such, we set out to determine the proportion of CRC-related hospital admissions and distribution of colon cancer by stage in different age groups.

METHODS

The NIS database for 2002-2012 was used to investigate trends of colorectal cancer resection by age, and the ACS NSQIP database for 2012-2013 was used to investigate contemporary stage at diagnosis for colon cancer in different age groups.

RESULTS

A total of 1,198,421 patients were admitted to a hospital with a diagnosis of CRC and captured by the NIS database. Although the number of hospitalized CRC patients decreased from 2002 to 2012, the observed decrease was predominant in patients older than 65 years (P < 0.01) and in colon cancer compared to rectal cancer patients (P < 0.01). The proportion of patients younger than 65 years increased from 32.8 % in 2002 to 41.1 % in 2012, and the proportion of patients under age 50 increased from 9 to 12 %. In the NSQIP database, the age <50 group also had a significantly higher proportion of advanced disease (stage III/IV) compared to patients age 50 and older (62.3 vs. 47.5 %, P < 0.01). In 2012, it was observed that most patients with rectal cancer were younger than 65 years (55.8 %).

CONCLUSION

There was a steady decrease in the number of hospitalized patients with colorectal cancer during the last decade, primarily attributable to a decrease in the older than 65 years age patients and colon cancer patients. The proportion of hospitalized patients age <50 is rising. In addition, patients younger than 50 years were more likely to have advanced disease compared to older patients.

Genetic architecture of colorectal cancer

Colorectal cancer (CRC) is a complex disease that develops as a consequence of both genetic and environmental risk factors. A small proportion (3-5%) of cases arise from hereditary syndromes predisposing to early onset CRC as a result of mutations in over a dozen well defined genes. In contrast, CRC is predominantly a late onset 'sporadic' disease, developing in individuals with no obvious hereditary syndrome. In recent years, genome wide association studies have discovered that over 40 genetic regions are associated with weak effects on sporadic CRC, and it has been estimated that increasingly large genome wide scans will identify many additional novel genetic regions. Subsequent experimental validations have identified the causally related variant(s) in a limited number of these genetic regions. Further biological insight could be obtained through ethnically diverse study populations, larger genetic sequencing studies and development of higher throughput functional experiments. Along with inherited variation, integration of the tumour genome may shed light on the carcinogenic processes in CRC. In addition to summarising the genetic architecture of CRC, this review discusses genetic factors that modify environmental predictors of CRC, as well as examples of how genetic insight has improved clinical surveillance, prevention and treatment strategies. In summary, substantial progress has been made in uncovering the genetic architecture of CRC, and continued research efforts are expected to identify additional genetic risk factors that further our biological understanding of this disease. Subsequently these new insights will lead to improved treatment and prevention of colorectal cancer.

Colorectal cancer in iran: molecular epidemiology and screening strategies

Purpose. The increasing incidence of colorectal cancer (CRC) in the past three decades in Iran has made it a major public health burden. This study aimed to report its epidemiologic features, molecular genetic aspects, survival, heredity, and screening pattern in Iran. Methods. A comprehensive literature review was conducted to identify the relevant published articles. We used medical subject headings, including colorectal cancer, molecular genetics, KRAS and BRAF mutations, screening, survival, epidemiologic study, and Iran. Results. Age standardized incidence rate of Iranian CRCs was 11.6 and 10.5 for men and women, respectively. Overall five-year survival rate was 41%, and the proportion of CRC among the younger age group was higher than that of western countries. Depending on ethnicity, geographical region, dietary, and genetic predisposition, mutation genes were considerably diverse and distinct among CRCs across Iran. The high occurrence of CRC in records of relatives of CRC patients showed that family history of CRC was more common among young CRCs. Conclusion. Appropriate screening strategies for CRC which is amenable to early detection through screening, especially in relatives of CRCs, should be considered as the first step in CRC screening programs.

Mortality determinants in colorectal cancer patients at different grades: a prospective, cohort study in Iran

BACKGROUND

Colorectal cancer (CRC) is an important cause of mortality and morbidity in many communities worldwide. This population based study was conducted to assess determinants of colorectal mortality in Iranian patients.

MATERIALS AND METHODS

A cohort of 1,127 cases of confirmed colorectal cancer registered in a population based registry covering 10 referral hospital in Tehran, Iran, were followed for five years. Information about tumor characteristics, smoking status and family history were collected at base line and survival status were followed every six months by contacting patient or next of kin (if patients died during the follow-up). The cause of death for each case was validated by verbal autopsy and referring to patient medical records at the time of death. The data were analyzed by Stata software using univariate and multivariate analysis (Cox regression). In building the model a p value of less than 5% was considered as significant.

RESULTS

The age at diagnosis was 53.5±14 years. Sixty one percent were male. Colorectal mortality among the patients was 96.9 person-years among men and 83 person-years among women. Seventy five percent of patients lived for 2.72 years, 50% for 5.83, and 25% for 13 years after the diagnosis of colorectal cancer. The age at diagnosis was significantly different between men and women (p<0.03). Higher tumor grade predicted higher death rate; the adjusted hazard ratios were 1.79 (95%CI, 0.88-3.61), 2.16 (95%CI, 1.07-4.37), and 3.1 (95%CI, 1.51-6.34) for grades II, III, and IV respectively when they were compared with grade I as reference. Ethnicity, marital status, family history of cancer, and smoking were related to survival with different degrees of magnitude.

CONCLUSIONS

Among many factors related to survival among the colorectal patients, tumor grade and smoking showed the highest magnitudes of association.

Diets high in resistant starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs

The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total of thirty female pigs (body weight 63.1 (sem 4.4) kg) were fed a low-DF, high-fat Western-style control diet (WSD), an AX-rich diet (AXD) or a RS-rich diet (RSD) for 3 weeks. Diet significantly affected the digestibility of DM, protein, fat, NSP and NSP components, and the arabinose:xylose ratio, as well as the disappearance of NSP and AX in the large intestine. RS was mainly digested in the caecum. AX was digested at a slower rate than RS. The digesta from AXD-fed pigs passed from the ileum to the distal colon more than twice as fast as those from WSD-fed pigs, with those from RSD-fed pigs being intermediate (P< 0.001). AXD feeding resulted in a higher number of Faecalibacterium prausnitzii, Roseburia intestinalis, Blautia coccoides-Eubacterium rectale, Bifidobacterium spp. and Lactobacillus spp. in the faeces sampled at week 3 of the experimental period (P< 0.05). In the caecum, proximal and mid colon, AXD feeding resulted in a 3- to 5-fold higher pool size of butyrate compared with WSD feeding, with the RSD being intermediate (P <0.001). In conclusion, the RSD and AXD differently affected digestion processes compared with the WSD, and the AXD most efficiently shifted the microbial composition towards butyrogenic species in the faeces and increased the large-intestinal butyrate pool size.

Occupational exposures and colorectal cancers: A quantitative overview of epidemiological evidence

A traditional belief widespread across the biomedical community was that dietary habits and genetic predisposition were the basic factors causing colorectal cancer. In more recent times, however, a growing evidence has shown that other determinants can be very important in increasing (or reducing) incidence of this malignancy. The hypothesis that environmental and occupational risk factors are associated with colorectal cancer is gaining ground, and high risks of colorectal cancer have been reported among workers in some industrial branches. The aim of this study was to investigate the epidemiologic relationship between colorectal cancer and occupational exposures to several industrial activities, by means of a scientific literature review and meta-analysis. This work pointed out increased risks of colorectal cancer for labourers occupied in industries with a wide use of chemical compounds, such as leather (RR = 1.70, 95%CI: 1.24-2.34), basic metals (RR = 1.32, 95%CI: 1.07-1.65), plastic and rubber manufacturing (RR = 1.30, 95%CI: 0.98-1.71 and RR = 1.27, 95%CI: 0.92-1.76, respectively), besides workers in the sector of repair and installation of machinery exposed to asbestos (RR = 1.40, 95%CI: 1.07-1.84). Based on our results, the estimated crude excess risk fraction attributable to occupational exposure ranged from about 11% to about 15%. However, homogeneous pattern of association between colorectal cancer and industrial branches did not emerge from this review.

Incidence trends of colorectal cancer in the West of Iran during 2000-2005

BACKGROUND

Colorectal cancer is a main leading cause of cancer death in western countries. Although many studies have been conducted on incidence trends all over the world in recent years, information regarding changes in incidence of colorectal cancer in Iran is insufficient. The present study of colorectal cancer in the west of Iran during recent years was therefore performed.

MATERIALS AND METHODS

The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Ministry of Health and Medical Education, Center for Disease Control and Management. The codes from 18-21 among cancers were selected for colon and rectum cancers. Incidence rates were standardized directly using WHO population. The significance of incidence rate trends during 2000-2005 was tested through Poisson regression.

RESULTS

762 cases of colorectal cancer were observed during 6 years in this region, with a gender ratio of men to women of 1.2. It increased from 65 cases in 2000 to 213 cases in 2005 or from 1.5 per100,000 per persons per year to 4.8. Significant increasing trends were evident in Kermanshah and Hamadan provinces; however, change did not reach significance in Ilam and Kurdistan provinces.

CONCLUSIONS

Colorectal cancer has an increasing trend in the west of Iran. Although it seems that the increasing rate of colorectal cancer is due to increasing of cancer risk factors, some proportion may be related to the improvement of surveillance systems in Iran.

Discussing cancer: communication with African Americans

Regular screening for colorectal cancer (CRC) facilitates earlier detection, lowers mortality, and may reduce incidence through detection and removal of pre-cancerous polyps. Optimizing health professional delivery of CRC screening information and recommendations can assist in reducing CRC disparity in the African-American community. This article presents qualitative data on African Americans' attitudes about health professional CRC communications based on the analysis of focus groups (N = 79). Using a social-ecological framework, colorectal cancer and professional communication themes are examined to offer four general and nine cancer-specific theoretically based and culturally appropriate strategies for improving health professional cancer communication with African Americans.

Different human gut models reveal the distinct fermentation patterns of Arabinoxylan versus inulin

Different in vitro models have been developed to assess how food compounds affect the human gut microbiota. Using two such models (SHIME(R) and TIM-2), we compared how long-chain arabinoxylan (LC-AX), a wheat-derived potentially prebiotic fiber, and inulin (IN), a well-established prebiotic compound, modulate SCFA production and bifidobacteria composition. While both the SHIME and TIM-2 differ in experimental design, they both demonstrated that LC-AX and IN specifically increased the health-promoting metabolites propionate and butyrate, respectively. Furthermore, LC-AX stimulated Bifidobacterium longum, while IN stimulated other bifidobacteria including Bifidobacterium adolescentis. The SHIME experiment also revealed that effects of LC-AX were more persistent during the 2-week wash-out period. These results confirm a recent in vivo study, during which humanized rats were treated with the same LC-AX/IN. In conclusion, results from different human gut models suggest that, besides IN, LC-AX are promising prebiotic candidates with high specificity toward Bifidobacterium longum and a selective propionate increase.

Lactobacillus acidophilus CRL 1014 improved "gut health" in the SHIME reactor

BACKGROUND

How to maintain "gut health" is a goal for scientists throughout the world. Therefore, microbiota management models for testing probiotics, prebiotics, and synbiotics have been developed.

METHODS

The SHIME model was used to study the effect of Lactobacillus acidophilus 1014 on the fermentation pattern of the colon microbiota. Initially, an inoculum prepared from human feces was introduced into the reactor vessels and stabilized over 2-wk using a culture medium. This stabilization period was followed by a 2-wk control period during which the microbiota was monitored. The microbiota was then subjected to a 4-wk treatment period by adding 5 mL of sterile peptone water with L. acidophilus CRL1014 at the concentration of 10⁸ CFU/mL to vessel one (the stomach compartment). Plate counts, Denaturing Gradient Gel Electrophoresis (DGGE), short-chain fatty acid (SCFA) and ammonium analyses were carried out for monitoring of the microbial community from the colon compartments.

RESULTS

A significant increase (p < 0.01) in the Lactobacillus spp. and Bifidobacterium spp. populations was observed during the treatment period. The DGGE obtained showed changes in the lactobacilli community from the colon compartments of the SHIME reactor. The (SCFA) concentration increased (p < 0.01) during the treatment period, due mainly to significant increased levels of acetic, butyric, and propionic acids. However, ammonium concentrations decreased during the same period (p < 0.01).

CONCLUSIONS

This study showed the beneficial influence of L. acidophilus CRL 1014 on microbial metabolism and lactobacilli community composition for improving human health.

Noninvasive visualization of tumor growth in a human colorectal liver metastases xenograft model using bioluminescence in vivo imaging

BACKGROUND

Bioluminescence imaging (BLI) is an ideal tool for noninvasive, quantitative monitoring of tumor progression/regression in animal models. The effectiveness of different treatment strategies is displayed by an altered intensity of bioluminescence, demonstrating a change of the tumor burden. The aim of this study was to establish a reliable, reproducible colorectal hepatic metastases cancer animal model.

METHODS

Cells of the human colon carcinoma cell line HCT-116 Luc(pos) expressing the firefly luciferase enzyme gene were used. HCT-116 Luc(pos) cells (2.5 × 10(6)) were injected through the portal vein into the liver of immunoincompetent nude mice. BLI was used to analyze intrahepatic tumor burden and growth kinetic.

RESULTS

HCT-116 Luc(pos) cells demonstrated a progressive and reproducible growth in the liver after intraportal injection. Four days after injection, the animals were analyzed for tumor growth by BLI, and mice without or too low bioluminescence signals were excluded (between 10% and 20% animals). HCT-116 Luc(pos) intrahepatic tumors responded successfully to different dosages (5 and 10 mg/kg) of 5-fluorouracil.

CONCLUSIONS

BLI is an important tool with many potential advantages for investigators. The measurement of intrahepatic tumor growth by imaging luciferase activity noninvasively provides valuable information on tumor burden and effectiveness of therapy. Thus, the presented intrahepatic metastases model based on the growth of HCT-116 Luc(pos) cells is suitable for in vivo testing of different cancer therapy strategies.

Cancer of the colon and rectum: potential effects of sex-age interactions on incidence and outcome

Background

Sex differences in epidemiological, clinical and pathological characteristics of colorectal cancer have been under intensive investigation for the last three decades. Given that most of the sex-related differences reported were also age-related, this study sought to determine the potential effect of a sex-age interaction on colorectal cancer development and progression.

Material/Methods

Statistical data on sex- and age-specific colon or rectal cancer incidence, disease stage and survival for white persons were derived from the United States Surveillance, Epidemiology and End Results (SEER) Program. Age-specific incidence rates in 2002–2006 were analyzed by 5-year age groups (45–49, 50–54, 55–59, 60–64, 65–69, 70–74, 75–79, 80–84 years) in men and women. Sex differences were measured by calculating rate differences (RD) and rate ratios (RR). Equivalent analyses for a similar time period were performed for stage distribution and 5-year relative survival.

Results

Age-specific incidence rates were higher for men, for all life-time periods. However, the magnitude of the male predominance was age-dependent. The RR and RD did not remain constant over time: they increased gradually with age, peaked at 70–74 years, and declined thereafter. The distribution of stage at diagnosis was similar between men and women, but women seemed to have better survival, until the age of 64 years for colon cancer and 74 years for rectal cancer.

Conclusions

There seem to be significant age-related sex differences in the incidence of colorectal cancer, and maybe also in its prognosis.

Four years incidence rate of colorectal cancer in Iran: a survey of national cancer registry data - implications for screening

INTRODUCTION

Design and implementation of screening programs in each country must be based on epidemiological data. Despite the relatively high incidence of CRC, there is no nationwide comprehensive program for screening in Iran. This study was designed to investigate national CRC data and help to determine guidelines for screening.

METHODS

Incidence data used in this study were obtained from Iranian annual of National Cancer Registration report. Age standardized rates (ASR)were calculated using world standard population and were categorized by age, sex, anatomic subsite and morphology of tumor. Data were analyzed using SPSS.V.13 and Open Source Epidemiologic Statistics for Public Health software (OpenEpi v.2.3.1).

RESULTS

A quarter of cases were less than 50 years of age. The majority of tumors were detected in the colon. The overall ASR in the four years period was 38.0 per 100000 and was higher for men compared women (P<0.05). Incidence rate of colorectal cancer increased with age.

CONCLUSION

Results of present study indicated that incidence of colorectal cancer is relatively high in Iran. Incidence of CRC in people under 50 years and in rectum were reported higher than other countries that related etiologic factors should be investigate in further studies. According to the increasing of ASR after age 50 years, it seems that onset of screening at age 50 would be appropriate.

More than two decades of Apc modeling in rodents

Mutation of tumor suppressor gene adenomatous polyposis coli (APC) is an initiating step in most colon cancers. This review summarizes Apc models in mice and rats, with particular concentration on those most recently developed, phenotypic variation among different models, and genotype/phenotype correlations.

Identification of key players for colorectal cancer metastasis by iTRAQ quantitative proteomics profiling of isogenic SW480 and SW620 cell lines

This study compared the whole cell proteome profiles of two isogenic colorectal cancer (CRC) cell lines (primary SW480 cell line and its lymph node metastatic variant SW620), as an in vitro metastatic model, to gain an insight into the molecular events of CRC metastasis. Using iTRAQ (isobaric tags for relative and absolute quantitation) based shotgun proteomics approach, we identified 1140 unique proteins, out of which 147 were found to be significantly altered in the metastatic cell. Ingenuity pathway analysis with those significantly altered proteins, revealed cellular organization and assembly as the top-ranked altered biological function. Differential expression pattern of 6 candidate proteins were validated by Western blot. Among these, the low expression level of β-catenin combined with the up-regulation of CacyBP (Calcyclin binding Protein), a β-catenin degrading protein, in the metastatic cell provided a rational guide for the downstream functional assays. The relative expression pattern of these two proteins was further validated in three other CRC cells by Western blot and quantitative immunofluorescence studies. Overexpression of CacyBP in three different primary CRC cell lines showed significant reduction in adhesion characteristics as well as cellular β-catenin level as confirmed by our experiments, indicating the possible involvement of CacyBP in CRC metastasis. In short, this study demonstrates successful application of a quantitative proteomics approach to identify novel key players for CRC metastasis, which may serve as biomarkers and/or drug targets to improve CRC therapy.

Arabinoxylans and inulin differentially modulate the mucosal and luminal gut microbiota and mucin-degradation in humanized rats

The endogenous gut microbiota affects the host in many ways. Prebiotics should favour beneficial intestinal microbes and thus improve host health. In this study, we investigated how a novel class of potential prebiotic long-chain arabinoxylans (LC-AX) and the well-established prebiotic inulin (IN) modulate the gut microbiota of humanized rats. Six weeks after axenic rats were inoculated with a human faecal microbiota, their colonic microbiota was similar to this inoculum (∼ 70%), whereas their caecal microbiota was enriched with Verrucomicrobia and Firmicutes concomitant with lower abundance of Bacteroidetes. Moreover, different Bifidobacterium species colonized the lumen (B. adolescentis) and mucus (B. longum and B. bifidum). Both LC-AX and IN increased SCFA levels and induced a shift from acetate towards health-promoting propionate and butyrate respectively. By applying a high-resolution phylogenetic micro-array (HITChip) at the site of fermentation (caecum), IN and LC-AX were shown to stimulate bacterial groups with known butyrate-producers (Roseburia intestinalis, Eubacterium rectale, Anaerostipes caccae) and bifidobacteria (B. longum) respectively. Prebiotic administration also resulted in lower caecal abundances of the mucin-degrading Akkermansia muciniphila and potentially more mucin production by the host. Both factors might explain the increased caecal mucin levels for LC-AX (threefold) and IN (sixfold). These mucins were degraded along the colon, resulting in high faecal abundances of Akkermansia muciniphila for LC-AX and especially IN-treated rats. Finally, the microbial changes caused an adaptation period for the host with less weight gain, after which the host fine-tuned the interaction with this altered microbiota. Our results demonstrate that next to IN, LC-AX are promising prebiotic compounds by stimulating production of health-promoting metabolites by specific microbes in the proximal regions. Further, prebiotic supplementation shifted mucin degradation to distal regions, where mucin-degraders may produce beneficial metabolites (e.g. propionate by Akkermansia muciniphila), so that prebiotics may potentially improve gut health along the entire length of the intestine.

Colorectal cancer epidemiology: incidence, mortality, survival, and risk factors

In this article, the incidence, mortality, and survival rates for colorectal cancer are reviewed, with attention paid to regional variations and changes over time. A concise overview of known risk factors associated with colorectal cancer is provided, including familial and hereditary factors, as well as environmental lifestyle-related risk factors such as physical inactivity, obesity, smoking, and alcohol consumption.

The intraportal injection model for liver metastasis: advantages of associated bioluminescence to assess tumor growth and influences on tumor uptake of radiolabeled anti-carcinoembryonic antigen antibody

BACKGROUND

Radioimmunotherapy is emerging as a new tool for adjuvant therapy of colorectal cancer. The liver remains the main site for metastases, carrying a high mortality rate. Many animal models are available but none associates easy, reliable implantation and in-vivo follow-up for experimental therapeutic studies. The aims of this study were to develop a reliable hepatic metastatic colonic cancer model in mice using the intraportal route for injection, with follow-up by bioluminescence (BLI) and to evaluate the impact of tumor location on tumor antigen direct targeting using radiolabeled anti-CEA (carcinoembryonic antigen) antibodies.

METHODS

Ls-174T Luc+ is a colon carcinoma cell line strongly expressing CEA, transfected with the luciferase gene for BLI. Isolated or aggregated cells (1×10(6)) were injected through the portal vein. The tumor burden was investigated using BLI to assess hepatic implantation and growth kinetics. The biodistribution of the 125I anti-CEA antibody fragment (F6) was studied in this model and was compared with subcutaneous implantation.

RESULTS

The tumor implantation rate was 100% using aggregated cells compared with 26.6% of isolated cells. Photons emitted by 1×10(6) cells were detected by BLI immediately after injection and allowed visual confirmation of hepatic distribution. The tumor growth was assessed over time to select homogeneous groups of animals. Radiolabeled anti-CEA antibody biodistributions showed a significantly higher uptake in hepatic than in subcutaneous tumors.

CONCLUSION

The association of hepatic tumor graft through the portal route and BLI provides a reliable animal model and permits sensitive in-vivo detection and follow-up of hepatic metastases. The hepatic model seems to more closely reproduce colon cancer metastases compared with subcutaneous metastasis. The hepatic model is of particular interest for studying radioimmunotherapy.

African American's self-report patterns using the National Cancer Institute Colorectal Cancer Screening questionnaire

Studies that examine colorectal cancer screening (CRCS) behaviors and correlates rely on self-reports of screening status. Self-reports of CRCS may be more biased than other self-reported cancer screening because of multiple screening options, tests may be offered in combination, and screening schedules differ for each test. The National Cancer Institute (NCI) sponsored the development of a core set of questions to measure self-reported CRCS that are consistent with current guidelines, the NCI Colorectal Cancer Screening questionnaire (NCI CRCS). Several studies support the validity and reliability of this measure; however, none of the existing studies have described African American (AA) responses to items that might be important to clinical decision making and research related to screening adherence. This paper addresses the limited descriptions of AA response patterns to items that comprise the NCI CRCS. The NCI CRCS was administered to 439 AAs 50 to 75 years, participating in the baseline survey of a Center for Excellence in Cancer Communication CRC study. The survey measured self-reported CRCS, factors associated with screening, and response patterns to items that might affect estimates of screening and screening adherence. AA participants reported on CRCS, the test used, and time interval since last screening. Except for queries related to month and year of screening, few participants reported uncertainty in response to items. Two thirds of participants reported receiving CRCS; however, less than half of participants were adherent to guidelines. Less than half reported healthcare provider recommendations to screen. AA participants responded to items on the NCI CRCS as developed. Until new strategies or items are available, interval since last screening appears to be the most appropriate item to estimate AA self-reported CRCS adherence. Strategies are needed to increase physician recommendation to screen.