Colon cancer screening

The utility of inpatient work-up of incidental anemia during hospitalization for an acute medical condition: a retrospective cohort study

INTRODUCTION

The best timing for evaluation of anemia is not well defined and the clinical yield of performing workup during non-anemia-related hospitalization is unclear. We aimed to evaluate the prognostic value of inpatient laboratory anemia evaluation.

METHODS

This was a retrospective propensity-matched cohort study between the years 2013-2022 in Rabin Medical Center Israel. We included all patients admitted for non-anemia-related reasons and were found to be anemic. Patients were divided into groups based on basic laboratory anemia evaluation. Outcomes were cancer diagnosis, colonoscopy rate, duration of admission, and all-cause mortality. Multivariable analysis with competing risk of death was performed and a p-value of 5% was considered significant.

RESULTS

Following matching, 4,238 patients were included in the evaluation group compared to 7,680 in the no-evaluation group. In-patient laboratory anemia evaluation was associated with gastrointestinal cancer and any cancer diagnosis - HR of 1.53 (95% CI, 1.15- 2.05) and HR of 1.23 (95% CI, 1.11-1.37) respectively. The rate of colonoscopy was higher, and anemia prevalence was lower in the evaluation group after 1-year follow-up. Intravenous iron treatment was more prevalent in the evaluation group. The laboratory anemia evaluation prolonged the admission (5 vs 4 days). There was no difference in the all-cause mortality across the 10-year follow-up.

CONCLUSION

Inpatient anemia evaluation with basic laboratory tests was found to be associated with an increase in outpatient gastrointestinal cancer diagnosis and showed clinical and diagnostic advantages. For patients who can benefit from early gastrointestinal cancer diagnosis, admission holds a valid opportunity to initiate the evaluation.

Identification of Genetic Factors Related With Nonhereditary Colorectal Polyposis and Its Recurrence Through Genome-Wide Association Study

BACKGROUND

Many patients with colorectal polyposis demonstrate negative results in germline mutation test. This study aimed to uncover genetic variants associated with nonhereditary colorectal polyposis using a genome-wide association study (GWAS).

METHODS

At a single referral university hospital, between January 2012 and September 2021, 638 patients with ≥ 10 biopsy-proven cumulative polyps on colonoscopy without germline mutations related to hereditary colorectal cancer or polyposis were included. The control group comprised 1863 individuals from the Korea Medical Institute, each having undergone at least two colonoscopies, all of which were normal. This study utilized GWAS to identify susceptibility loci for nonhereditary colorectal polyposis. Genetic differences between patients with and without ≥ 10 polyp recurrences were analyzed using Cox proportional hazards models.

RESULTS

GWAS revealed 71 novel risk single-nucleotide polymorphisms (SNPs) not seen in previous colorectal cancer and polyp GWAS. Five genes (UPF3A, BICRA, CBWD6, PDE4DIP, and ABCC4) overlapping seven SNPs (rs566295755, rs2770288, rs1012003, rs201270202, rs71264659, rs1699813, and rs149368557), previously linked to colorectal cancer, were identified as significant risk factors for nonhereditary colorectal polyposis. Two novel genes (CNTN4 and CNTNAP3B), not previously associated with colorectal diseases, were identified. Three SNPs (rs149368557, rs12438834, and rs9707935) were significantly associated with higher risk of recurrence of polyposis. The gene overlapping with rs149368557 was ABCC4, which was also significantly associated with an increased risk of nonhereditary colorectal polyposis.

CONCLUSION

This study identified 71 novel risk variants for nonhereditary colorectal polyposis, with three SNPs (rs149368557, rs12438834, and rs9707935) indicating significant associations with increased risk of polyposis recurrence.

Exogenous Insulin Therapy Is Associated with the Risk of Advanced Colorectal Adenoma in Patients with Diabetes Mellitus

BACKGROUND/AIMS

Exogenous insulin therapy increases systemic exposure to insulin which may promote the development of colorectal neoplasia. We sought to evaluate the association between exogenous insulin therapy and the incidence of advanced adenoma in type 2 diabetes mellitus.

METHODS

A retrospective cohort study was conducted from January 1, 2007, to January 1, 2018, in a regional health system serving the United States Philadelphia metropolitan area, Central New Jersey, and South Central Pennsylvania. Study patients consisted of a random sample of patients with type 2 diabetes mellitus aged 40-80 years who had undergone two rounds of colonoscopy examinations. The exposure was cumulative duration of insulin therapy (i.e., no use, 1-365 days and > 365 days). The outcome was time to incident advanced adenoma.

RESULTS

Of the 975 eligible patients, 184 patients accumulated > 365 days of insulin therapy before the follow-up colonoscopy. The mean (standard deviation) duration between the two rounds of colonoscopy examination was 5.1 (2.9) years among the insulin users and 5.3 (3.9) years among non-users. Compared to no insulin exposure, receiving > 365 days of insulin therapy was associated with an increased incidence of advanced adenoma (adjusted hazard ratio [aHR] 4.84, 95% confidence interval [CI] 2.82-8.30), right-sided advanced adenoma (aHR 5.48, 95% CI 2.90-10.35), and 3 or more adenomas (aHR 2.61, 95% CI 1.46-4.69) at the follow-up colonoscopy examination.

CONCLUSION

Insulin therapy is associated with an increased risk of advanced adenoma and may serve as a novel risk-stratification factor to enhance the efficiency of existing colorectal cancer screening and surveillance programs.

Using of endoscopic polypectomy in patients with diagnosed malignant colorectal polyp - The cross-sectional clinical study

The aim of this study was to evaluate the efficacy of endoscopic polypectomy as a therapeutic treatment for malignant alteration of colorectal polyps. In a 5-year research, 89 patients were included, who were tested and treated at the University Clinical Center Kragujevac, Kragujevac, Serbia, with the confirmed presence of malignant alteration polyps of the colon by colonoscopy, which were removed using the method of endoscopic polypectomy and confirmed by the histopathological examination of the entire polyp. After that, the same group of patients was monitored endoscopically within a certain period, controlling polypectomy locations and the occurrence of a possible remnant of the polyp, in the period of up to 2 years of polypectomy. We observed that, with an increasing size of polyps, there is also an increase in the percentage of the complexity of endoscopic resection and the appearance of remnant with histological characteristics of the invasive cancer. The highest percentage of incomplete endoscopic resection and the appearance of remnant with histological characteristics of the invasive cancer were shown at malignant altered polyps in the field of tubulovillous adenoma. Eighteen patients in total underwent the surgical intervention. In conclusion, our data support the high efficacy of endoscopic polypectomy for the removal of the altered malignant polyp.

Clinical characteristics and risk factors related to polyposis recurrence and advanced neoplasm development among patients with non-hereditary colorectal polyposis

BACKGROUND/AIMS

Patients with more than 10 cumulative polyps might involve a greater genetic risk of colorectal neoplasia development. However, few studies have investigated the risk factors of polyposis recurrence and development of advanced neoplasms among patients with non-hereditary colorectal polyposis.

METHODS

This study included patients (n=855) with 10 or more cumulative polyps diagnosed at Severance Hospital from January 2012 to September 2021. Patients with known genetic mutations related to polyposis, known hereditary polyposis syndromes, insufficient information, total colectomy, and less than 3 years of follow-up were excluded. Finally, 169 patients were included for analysis. We collected clinical data, including colonoscopy surveillance results, and performed Cox regression analyses of risk factors for polyposis recurrence and advanced neoplasm development.

RESULTS

The 169 patients were predominantly male (84.02%), with a mean age of 64.19±9.92 years. The mean number of adenomas on index colonoscopy was 15.33±8.47. Multivariable analysis revealed history of cancer except colon cancer (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.23-4.01), current smoking (HR, 2.39; 95% CI, 1.17-4.87), and detection of many polyps (≥15) on index colonoscopy (HR, 2.05; 95% CI, 1.21-3.50) were significant risk factors for recurrence of polyposis. We found no statistically significant risk factors for advanced neoplasm development during surveillance among our cohort.

CONCLUSIONS

The presence of many polyps (≥15) on index colonoscopy, history of cancer except colon cancer, and current smoking state were significant risk factors for polyposis recurrence among patients with non-hereditary colorectal polyposis.

A comprehensive survey of intestine histopathological image analysis using machine vision approaches

Colorectal Cancer (CRC) is currently one of the most common and deadly cancers. CRC is the third most common malignancy and the fourth leading cause of cancer death worldwide. It ranks as the second most frequent cause of cancer-related deaths in the United States and other developed countries. Histopathological images contain sufficient phenotypic information, they play an indispensable role in the diagnosis and treatment of CRC. In order to improve the objectivity and diagnostic efficiency for image analysis of intestinal histopathology, Computer-aided Diagnosis (CAD) methods based on machine learning (ML) are widely applied in image analysis of intestinal histopathology. In this investigation, we conduct a comprehensive study on recent ML-based methods for image analysis of intestinal histopathology. First, we discuss commonly used datasets from basic research studies with knowledge of intestinal histopathology relevant to medicine. Second, we introduce traditional ML methods commonly used in intestinal histopathology, as well as deep learning (DL) methods. Then, we provide a comprehensive review of the recent developments in ML methods for segmentation, classification, detection, and recognition, among others, for histopathological images of the intestine. Finally, the existing methods have been studied, and the application prospects of these methods in this field are given.

Clinical Multigene Panel Testing Identifies Racial and Ethnic Differences in Germline Pathogenic Variants Among Patients With Early-Onset Colorectal Cancer

PURPOSE

The early-onset colorectal cancer (EOCRC) burden differs across racial/ethnic groups, yet the role of germline genetic predisposition in EOCRC disparities remains uncharacterized. We defined the prevalence and spectrum of inherited colorectal cancer (CRC) susceptibility gene variations among patients with EOCRC by race and ethnicity.

PATIENTS AND METHODS

We included individuals diagnosed with a first primary CRC between age 15 and 49 years who identified as Ashkenazi Jewish, Asian, Black, Hispanic, or White and underwent germline genetic testing of 14 CRC susceptibility genes performed by a clinical testing laboratory. Variant comparisons by racial and ethnic groups were evaluated using chi-square tests and multivariable logistic regression adjusted for sex, age, CRC site, and number of primary colorectal tumors.

RESULTS

Among 3,980 patients with EOCRC, a total of 530 germline pathogenic or likely pathogenic variants were identified in 485 individuals (12.2%). By race/ethnicity, 12.7% of Ashkenazim patients, 9.5% of Asian patients, 10.3% of Black patients, 14.0% of Hispanic patients, and 12.4% of White patients carried a germline variant. The prevalence of Lynch syndrome (P = .037), as well as APC, CHEK2, MLH1, monoallelic MUTYH, and PTEN variants, varied by race/ethnicity among patients with EOCRC (all P < .026). Ashkenazim and Hispanic patients had significantly higher odds of presenting with a pathogenic APC variant, which included p.I1307K (odds ratio [OR], 2.67; 95% CI, 1.30 to 5.49; P = .007) and MLH1 variant (OR, 8.69; 95% CI, 2.68 to 28.20; P = .0003), respectively, versus White patients in adjusted models.

CONCLUSION

Germline genetic features differed by race/ethnicity in young patients with CRC, suggesting that current multigene panel tests may not be representative of EOCRC risk in diverse populations. Further study is needed to optimize genes selected for genetic testing in EOCRC via ancestry-specific gene and variant discovery to yield equitable clinical benefits for all patients and to mitigate inequities in disease burden.

The Impact of Limited Language Proficiency in Screening for Breast Cancer

BACKGROUND

The prevalence of a culturally diverse population in the United States continues to grow. Nevertheless, the national impact of limited English proficiency (LEP) in breast cancer screening is still unknown.

METHODS

A retrospective review of the 2015 sample of the National Health Interview Survey database was performed. The cohort included women with and without LEP between 40 and 75 years. We evaluated differences in screening rates, baseline, socioeconomic, access to healthcare, and breast cancer risk factors with univariate and multivariate regression analyses.

RESULTS

The prevalence of LEP was 5.7% (N = 1825, weighted counts 3936,081). LEP women showed a statistically significant lower rate of overall screening mammograms (78% vs. 90%), fewer benign lumps removed (6.4% vs. 17%) and lower rates of access to healthcare variables. They showed a higher rate of nonprivate insurance and living below the poverty line, a lower rate of hormone replacement therapy (1.8% vs. 5.6%), older menarche (12.97 vs. 12.75) and a higher rate of current menstruation (36% vs. 24). LEP women were associated with a lower probability of having a screening mammogram in multivariate analysis (OR: 0.67, 95% CI: 0.51-0.87). When LEP was subdivided into Spanish and "other" languages, Spanish speakers were associated with a lower probability of a screening mammogram (OR 0.67, 95% CI 0.49-0.90) while controlling for the same covariates.

CONCLUSION

The results from our study showed that LEP women are associated with a lower probability of having a screening mammogram. Particularly, the Spanish speakers were found as a vulnerable subgroup.

Genetics, Genomics and Emerging Molecular Therapies of Pancreatic Cancer

The number of cases of pancreatic cancers in 2019 in Poland was 3852 (approx. 2% of all cancers). The course of the disease is very fast, and the average survival time from the diagnosis is 6 months. Only <2% of patients live for 5 years from the diagnosis, 8% live for 2 years, and almost half live for only about 3 months. A family predisposition to pancreatic cancer occurs in about 10% of cases. Several oncogenes in which somatic changes lead to the development of tumours, including genes BRCA1/2 and PALB2, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1, are involved in pancreatic cancer. Between 4% and 10% of individuals with pancreatic cancer will have a mutation in one of these genes. Six percent of patients with pancreatic cancer have NTRK pathogenic fusion. The pathogenesis of pancreatic cancer can in many cases be characterised by homologous recombination deficiency (HRD)-cell inability to effectively repair DNA. It is estimated that from 24% to as many as 44% of pancreatic cancers show HRD. The most common cause of HRD are inactivating mutations in the genes regulating this DNA repair system, mainly BRCA1 and BRCA2, but also PALB2, RAD51C and several dozen others.

Second Primary Cancers following Colorectal Cancer in Sicily, Italy

Simple Summary

This study addressed the under-investigated issue of second primary cancer occurring in colorectal cancer survivors. Our aim was to explore whether patients recovered from a first colorectal cancer were at higher risk of developing a subsequent primary cancer. The hypothesis was that exposure to cancer treatment, enhanced health surveillance and shared risk factors may lead to an excess risk of second primary cancer in this population. The number of cases of second primary cancer exceeded the expected in this population, mainly driven by female genital cancers, and especially observed in the first years after colorectal cancer diagnosis. Our findings are overall consistent with previous studies, providing valuable information to better characterize and predict mortality from second primary cancer in subjects who suffered from first colorectal cancer.

Abstract

Background: Cancer survivors are at risk of developing second primary cancers (SPC). We investigated the risk of SPC in colorectal cancer (CRC) survivors in Sicily, Southern Italy. Methods: We analyzed data from the Eastern Sicily cancer registry covering 2.5 million people diagnosed and followed up between 2003 and 2017. We calculated the standardized incidence ratio (SIR) and 95% confidence interval (CI) of SPC overall and by cancer type, using the general Sicily population rates as reference. Results: A total of 19,040 cases of CRC and 1453 cases of SPC were included in the analysis. Mean age of occurrence of SPC was 68.1. The SIR for any SPC was 1.11 (95% CI 1.05–1.17); it was higher in women (1.18; 95% CI 1.08–1.29) than in men (1.07; 95% CI 0.97–1.14, p-value of difference 0.07). The SIR was increased for SPC from the ovary (SIR 2.01; 95% CI 1.33–2.95), kidney (SIR 2.00; 95% CI 1.54–2.56), endometrium (SIR 1.94; 95% CI 1.45–2.54), bladder (SIR 1.22, 95% CI 1.04–1.43) and stomach (1.29; 95% CI 0.98–1.66). The SIR for CRC as SPC was 0.84 (95% CI 0.70–1.01). No increased incidence was found for lung, prostate, breast, thyroid and liver cancer. The SIR for SPC overall and several cancers decreased with time of follow-up. Conclusions: In this population, CRC survivors have an 11% higher risk of developing a SPC than the general population, particularly cancers of the ovary, kidney, endometrium, bladder and stomach. Follow-up for SPC is required, especially during the first 5 years from CRC diagnosis.

The Neurokinin-1 Receptor Is Essential for the Viability of Human Glioma Cells: A Possible Target for Treating Glioblastoma

Background

Glioblastoma or glioma is the most common malignant brain tumor. Patients have a prognosis of approximately 15 months, despite the current aggressive treatment. Neurokinin-1 receptor (NK-1R) occurs naturally in human glioma, and it is necessary for the tumor development.

Objective

The purpose of the study was to increase the knowledge about the involvement of the substance P (SP)/NK-1R system in human glioma.

Methods

Cellular localization of NK-1R and SP was studied in GAMG and U-87 MG glioma cell lines by immunofluorescence. The contribution of both SP and NK-1R to the viability of these cells was also assessed after applying the tachykinin 1 receptor (TAC1R) or the tachykinin 1 (TAC1) small interfering RNA gene silencing method, respectively.

Results

Both SP and the NK-1R (full-length and truncated isoforms) were localized in the nucleus and cytoplasm of GAMG and U-87 MG glioma cells. The presence of full-length NK-1R isoform was mainly observed in the nucleus, while the level of truncated isoform was higher in the cytoplasm. Cell proliferation was decreased when glioma cells were transfected with TAC1R siRNA, but not with TAC1. U-87 MG cells were more sensitive to the effect of the TAC1R inhibition than GAMG cells. The decrease in the number of glioma cells after silencing of the TAC1R siRNA gene was due to apoptotic and necrotic mechanisms. In human primary fibroblast cultured cells, TAC1R silencing by siRNA did not produce any change in cell viability.

Conclusions

Our results show for the first time that the expression of the TAC1R gene (NK-1R) is essential for the viability of GAMG and U-87 MG glioma cells. On the contrary, the TAC1R gene is not essential for the viability of normal cells, confirming that NK-1R could be a promising and specific therapeutic target for the treatment of glioma.

Identification of ß-Catenin Gene as a Colorectal Cancer Controller in Mice <i>(Mus musculus)</i> Induced by Azoxymethane (AOM) and Dextran Sulfate Sodium (DSS) Using PCR RFLP Method with EcoR1 and Hinif1

Colorectal cancer is cancer attacking the colon to the rectum. The pathophysiology of colorectal cancer occurs due to several causes, such as changes in normal colonic epithelial cells histopathologically through molecular processes. Another cause is that the adenomatous polyps become colorectal cancer due to the carcinogenesis process. Most colorectal cancers originate from adenocarcinomas. Colon cancer is characterized by the uncontrolled growth of cells in the epithelial lining of the large intestine. The type of this study was laboratory experimental research. The population was 2 mice that had been induced by Azoxymethane (AOM) and Dextran sulfate sodium (DSS) and 1 mouse did not get any treatment for 2 months. From the result, the results of RFLP on PCR products from 3 samples that had been used showed that only one sample showing the presence of the β-catenin gene by marking the formation of a 227bp Deoxy Nucleic Acid (DNA) band and testing the EcoR1 restriction enzyme did not show any cutting of DNA fragments with no DNA bands. The size of 81bp and 146bp for Hinf1 restriction showed a mutation in P3 with the formation of bands of 89bp and 138bp in the large intestine that had been induced by azoxymethane and dextran sodium sulfate. Through this study, it can be seen that the occurrence of mutations in the-catenin gene as a marker of colorectal cancer can be identified using the Hinif1 enzyme with the RFLP PCR method.

Clinically Relevant Genes and Proteins Modulated by Tocotrienols in Human Colon Cancer Cell Lines: Systematic Scoping Review

The last decade has witnessed tremendous growth in tocotrienols (T3s) research, especially in the field of oncology, owing to potent anticancer property. Among the many types of cancers, colorectal cancer (CRC) is growing to become a serious global health threat to humans. Chemoprevention strategies in recent days are open to exploring alternative interventions to inhibit or delay carcinogenesis, especially with the use of bioactive natural compounds, such as tocotrienols. This scoping review aims to distil the large bodies of literature from various databases to identify the genes and their encoded modulations by tocotrienols and to explicate important mechanisms via which T3s combat CRC. For this scoping review, research papers published from 2010 to early 2021 related to T3s and human CRC cells were reviewed in compliance with the PRISMA guidelines. The study included research articles published in English, searchable on four literature databases (Ovid MEDLINE, PubMed, Scopus, and Embase) that reported differential expression of genes and proteins in human CRC cell lines following exposure to T3s. A total of 12 articles that fulfilled the inclusion and exclusion criteria of the study were short-listed for data extraction and analysis. The results from the analysis of these 12 articles showed that T3s, especially its γ and δ analogues, modulated the expression of 16 genes and their encoded proteins that are associated with several important CRC pathways (apoptosis, transcriptional dysregulation in cancer, and cancer progression). Further studies and validation work are required to scrutinize the specific role of T3s on these genes and proteins and to propose the use of T3s to develop adjuvant or multi-targeted therapy for CRC.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

The impact of increasing multitarget stool DNA use among colorectal cancer screeners in a self-insured US employer population

Background: In the United States (US), colorectal cancer (CRC) is the second leading cause of cancer-related deaths. With the majority of the US population covered by employer-based health plans, employers can play a critical role in increasing CRC screening adherence, which may help avert CRC-related deaths. Therefore, it is important for self-insured employers to consider the impact of appropriate utilization of CRC screening options. Objective: To evaluate the impact of increasing multitarget stool DNA [mt-sDNA (Cologuard®)] use among CRC screeners from the perspective of a US self-insured employer. Methods:A 5-year Markov model was developed to quantify the budget impact of increasing mt-sDNA from 6% to 15% among average-risk screeners using colonoscopy, fecal immunological test, and mt-sDNA. Data on direct medical costs were obtained from published literature, Medicare CPT codes, and the Healthcare cost and Utilization project. Indirect costs included productivity loss due to workplace absenteeism for CRC screening and treatment. Results: With a hypothetical population of 100,000 employees with screeners aged 50-64 years, compared to status quo, increased mt-sDNA utilization resulted in no differences in the numbers of cancers detected and the overall direct and indirect cost savings were ~$214,000 ($0.04 per-employee-per-month) over 5 years. Most of the savings were due to a reduction in the direct medical expenditure related to CRC screening, adverse events, and productivity loss due to colonoscopy screening. Similar results were observed in the model simulation among screeners aged 45-64 years. Conclusion: Increased utilization of mt-sDNA for CRC screening averts direct and indirect medical costs from a self-insured US employer perspective.

Tissue-specific reduction in MLH1 expression induces microsatellite instability in intestine of Mlh1+/- mice

Tumors of Lynch syndrome (LS) patients display high levels of microsatellite instability (MSI), which results from complete loss of DNA mismatch repair (MMR), in line with Knudson's two-hit hypothesis. Why some organs, in particular those of the gastrointestinal (GI) tract, are prone to tumorigenesis in LS remains unknown. We hypothesized that MMR is haploinsufficient in certain tissues, compromising microsatellite stability in a tissue-specific manner before tumorigenesis. Using mouse genetics, we tested how levels of MLH1, a central MMR protein, affect age- and tissue-specific microsatellite stability in vivo and whether elevated MSI is detectable prior to loss of MMR function and to neoplastic growth. To assess putative tissue-specific MMR haploinsufficiency, we determined relevant molecular phenotypes (MSI, Mlh1 promoter methylation status, MLH1 protein and RNA levels) in jejuna of Mlh1^+/- mice and compared them to those in spleen, as well as to MMR-proficient and -deficient controls (Mlh1^+/+ and Mlh1^-/- mice). While spleen MLH1 levels of Mlh1^+/- mice were, as expected, approximately 50 % compared to wildtype mice, MLH1 levels in jejunum varied substantially between individual Mlh1^+/- mice and moreover, decreased with age. Mlh1^+/- mice with soma-wide Mlh1 promoter methylation often displayed severe MLH1 depletion in jejunum. Reduced (but still detectable) MLH1 levels correlated with elevated MSI in Mlh1^+/- jejunum. MSI in jejunum increased with age, while in spleens of the same mice, MLH1 levels and microsatellites remained stable. Thus, MLH1 expression levels are particularly labile in intestine of Mlh1^+/- mice, giving rise to tissue-specific MSI long before neoplasia. A similar mechanism likely also operates also in the human GI epithelium and could explain the wide range in age-of-onset of LS-associated tumorigenesis.

Molecular characterization of colorectal cancer: A five-gene prognostic signature based on RNA-binding proteins

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers worldwide. RNA-binding proteins (RBPs) regulate essential biological processes and play essential roles in a variety of cancers. The present study screened differentially expressed RBPs, analyzed their function and constructed a prognostic model to predict the overall survival of patients with CRC.

METHODS

We downloaded CRC RNA-sequencing data from the Cancer Genome Atlas (TCGA) portal and screened differentially expressed RBPs. Then, functional analyses of these genes were performed, and a risk model was established by multivariate Cox regression.

RESULTS

We obtained 132 differentially expressed RBPs, including 66 upregulated and 66 downregulated RBPs. Functional analysis revealed that these genes were significantly enriched in RNA processing, modification and binding, ribosome biogenesis, post-transcriptional regulation, ribonuclease and nuclease activity. Additionally, some RBPs were significantly related to interferon (IFN)-alpha and IFN-beta biosynthetic processes and the Toll-like receptor signaling pathway. A prognostic model was constructed and included insulin like growth factor 2 messenger ribonucleic acid binding protein 3 (IGF2BP3), poly (A) binding protein cytoplasmic 1 like (PABPC1L), peroxisome proliferator activated receptor gamma coactivator 1 alpha (PPARGC1A), peptidyl- transfer ribonucleic acid hydrolase 1 homolog (PTRH1) and tudor domain containing 7 (TDRD7). The model is an independent risk factor for clinicopathological characteristics.

CONCLUSION

Our study provided novel insights into the pathogenesis of CRC and constructed a prognostic gene model, which may be helpful for determining the prognosis of CRC.

Identification of Novel Pathogenic Sequence Variants of the Mismatch Repair Genes During Screening for Lynch Syndrome in a Single Centre of Eastern Hungary

Introduction

Lynch syndrome is an autosomal dominant disorder, most frequent leading to colon cancer. Identification of patients with Lynch syndrome and screening of their family members are available prevention approach that can significantly decrease mortality. Unfortunately, routine screening still does not belong to standard of care in Hungary. In this study, we performed a comprehensive screening in order to identify patients with mismatch repair (MMR) mutation between the years of 2011 and 2014. Identified mutations were compared with those already published in the international databases.

Patients and Methods

Patients who underwent treatment for colorectal cancer at the Surgical Institute of the University of Debrecen were screened using the modified Amsterdam and Bethesda Criteria. Immunohistochemistry and microsatellite analyses were performed in order to identify possible mutation carrier cases. Suspicious cases underwent DNA sequencing to detect mutations in the mismatch repair genes (hMLH1, hMSH2).

Results

All together 760 colorectal cancer patients were screened. A total of 28 patients were identified as possible MMR mutation carrier and underwent further genetic evaluation. Pathogenic sequence variants of the MMR gene were found in 5 patients. Hypermethylation of the promoter region of the hMLH1 gene was identified in 2 patients. Two out of the 5 pathogenic sequence variants of the MMR gene were first identified by our group while other 2 mutations were previously published as possible founder mutations.

Conclusion

Identification of families with Lynch syndrome, while challenging because of variable phenotypes at diagnosis, is feasible with available molecular biological technologies and crucial to reduce mortality caused by this syndrome.

Mlh1 heterozygosity and promoter methylation associates with microsatellite instability in mouse sperm

DNA mismatch repair (MMR) proteins play an important role in maintaining genome stability, both in somatic and in germline cells. Loss of MLH1, a central MMR protein, leads to infertility and to microsatellite instability (MSI) in spermatocytes, however, the effect of Mlh1 heterozygosity on germline genome stability remains unexplored. To test the effect of Mlh1 heterozygosity on MSI in mature sperm, we combined mouse genetics with single-molecule PCR that detects allelic changes at unstable microsatellites. We discovered 4.5% and 5.9% MSI in sperm of 4- and 12-month-old Mlh1^+/− mice, respectively, and that Mlh1 promoter methylation in Mlh1^+/− sperm correlated with higher MSI. No such elevated MSI was seen in non-proliferating somatic cells. Additionally, we show contrasting dynamics of deletions versus insertions at unstable microsatellites (mononucleotide repeats) in sperm.

Solid-pseudopapillary neoplasm of the pancreas in a patient with familial adenomatous polyposis: a case report

Background

Familial adenomatous polyposis (FAP) is characterized by the presence of hundreds to thousands of colonic polyps, and extracolonic manifestations are likely to occur. Pancreatic tumors are rare extracolonic manifestations in patients with FAP, among which solid-pseudopapillary neoplasm (SPN) are extremely rare. We report here a patient with an SPN of the pancreas found during the follow-up of FAP.

Case presentation

A 20-year-old woman was diagnosed with FAP 3 years previously by colonoscopy which revealed less than 100 colonic polyps within the entire colon. She complained of left upper abdominal pain and a 10-cm solid and cystic pancreatic tumor was found by computed tomography scan. Solid and cystic components within the tumor were seen on abdominal magnetic resonance imaging. Simultaneous laparoscopic resection of the distal pancreas and subtotal colectomy was performed. Histopathological findings confirmed the pancreatic tumor as an SPN without malignancy. Abnormal staining of beta-catenin was observed by immunohistochemical study. Multiple polyps in the colorectum were not malignant. Molecular biological analysis from peripheral blood samples revealed a decrease in the copy number of the promoter 1A and 1B region of the APC gene, which resulted in decreased expression of the APC gene.

Conclusions

A rare association of SPN with FAP is reported. The genetic background with relation to beta-catenin abnormalities is interesting to consider tumor development. So far, there are few reports of SPN in a patient with FAP. Both lesions were treated simultaneously by laparoscopic resection.

The Neurokinin-1 Receptor Antagonist Aprepitant: An Intelligent Bullet against Cancer?

Neurokinin-1 receptor (NK-1R) antagonists exert antitumor action, are safe and do not cause serious side-effects. These antagonists (via the NK-1R) exert multiple actions against cancer: antiproliferative and anti-Warburg effects and apoptotic, anti-angiogenic and antimetastatic effects. These multiple effects have been shown for a broad spectrum of cancers. The drug aprepitant (an NK-1R antagonist) is currently used in clinical practice as an antiemetic. In in vivo and in vitro studies, aprepitant also showed the aforementioned multiple antitumor actions against many types of cancer. A successful combination therapy (aprepitant and radiotherapy) has recently been reported in a patient suffering from lung carcinoma: the tumor mass disappeared and side-effects were not observed. Aprepitant could be considered as an intelligent bullet against cancer. The administration of aprepitant in cancer patients to prevent recurrence and metastasis after surgical procedures, thrombosis and thromboembolism is discussed, as is the possible link, through the substance P (SP)/NK-1R system, between cancer and depression. Our main aim is to review the multiple antitumor actions exerted by aprepitant, and the use of this drug is suggested in cancer patients. Altogether, the data support the reprofiling of aprepitant for a new therapeutic use as an antitumor agent.

Expression and diagnostic value of miR-34c and miR-141 in serum of patients with colon cancer

Expression of miR-34c and miR-141 in serum of colon cancer patients and their association with clinicopathological features and diagnostic value for colon cancer were investigated. A total of 64 patients with colon cancer admitted to Hubei Cancer Hospital from January 2016 to March 2018 were included in the experimental group, and 64 healthy subjects undergoing physical examination during the same period were the control group. The expression of miR-34c and miR-141 in serum of patients in the two groups were detected by RT-qPCR, and the association of miR-34c and miR-141 with the clinicopathological characteristics of colon cancer patients was analyzed. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of miR-34c and miR-141 in colon cancer. The expression of miR-141 in serum of patients in the experimental group was significantly higher than that in the control group (P<0.05). Expression of miR-34c in serum of patients in the experimental group was significantly lower than that in the control group (P<0.05) and the expression of miR-34c and miR-141 in serum of the experimental group were associated with tumor diameter, clinical stage, degree of differentiation and lymph node metastasis (P<0.05). AUC of serum miR-34c in the diagnosis of colon cancer was 0.857 (95% CI: 0.795-0.919), with the cut-off value of 0.800, the diagnostic sensitivity of 84.38%, and the specificity of 68.75% and AUC of serum miR-141 in the diagnosis of colon cancer was 0.876 (95% CI: 0.810-0.941), with the cut-off value of 0.282, the diagnostic sensitivity of 70.31%, and the specificity of 96.88%. The ROC curve for the diagnosis of colon cancer was further plotted in combination with serum miR-34c and miR-141. AUC of the two combined for the diagnosis of colon cancer was 0.929 (95% CI: 0.884-0.974), with the cut-off value of 0.566, the diagnostic sensitivity of 84.38%, and the specificity of 93.75%. In conclusion, miR-34c and miR-141 might be involved in the occurrence and progression of colon cancer and could be used as biological indicators for early diagnosis of colon cancer.

Projecting total costs and health consequences of increasing mt-sDNA utilization for colorectal cancer screening from the payer and integrated delivery network perspectives

Aims: To evaluate total costs and health consequences of a colorectal cancer (CRC) screening program with colonoscopy, fecal immunochemical tests (FIT), and expanded use of multitarget stool DNA (mt-sDNA) from the perspectives of Integrated Delivery Networks (IDNs) and payers in the United States.Materials and methods: We developed a budget impact and cost-consequence model that simulates CRC screening for eligible 50- to 75-year-old adults. A status quo scenario and an increased mt-sDNA scenario were modeled. The status quo includes the current screening mix of colonoscopy (83%), FIT (11%), and mt-sDNA (6%) modalities. The increased mt-sDNA scenario increases mt-sDNA utilization to 28% over 10 years. Costs for both the IDN and the payer perspectives incorporated diagnostic and surveillance colonoscopies, adverse events (AEs), and CRC treatment. The IDN perspective included screening program costs, composed of direct nonmedical (e.g. patient navigation) and indirect (e.g. administration) costs. It was assumed that IDNs do not incur the costs for stool-based screening tests or bowel preparation for colonoscopies.Results: In a population of one million covered lives, the 10-year incremental cost savings incurred by increasing mt-sDNA utilization was $16.2 M for the IDN and $3.3 M for the payer. The incremental savings per-person-per-month were $0.14 and $0.03 for the IDN and payer, respectively. For both perspectives, increased diagnostic colonoscopy costs were offset by reductions in screening colonoscopies, surveillance colonoscopies, and AEs. Extending screening eligibility to 45- to 75-year-olds slightly decreased the overall cost savings.Limitations: The natural history of CRC was not simulated; however, many of the utilized parameters were extracted from highly vetted natural history models or published literature. Direct nonmedical and indirect costs for CRC screening programs are applied on a per-person-per modality basis, whereas in reality some of these costs may be fixed.Conclusions: Increased mt-sDNA utilization leads to fewer colonoscopies, less AEs, and lower overall costs for both IDNs and payers, reducing overall screening program costs and increasing the number of cancers detected while maintaining screening adherence rates over 10 years.

The Neurokinin-1 Receptor Antagonist Aprepitant, a New Drug for the Treatment of Hematological Malignancies: Focus on Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy. To treat the disease successfully, new therapeutic strategies are urgently needed. One of these strategies can be the use of neurokinin-1 receptor (NK-1R) antagonists (e.g., aprepitant), because the substance P (SP)/NK-1R system is involved in cancer progression, including AML. AML patients show an up-regulation of the NK-1R mRNA expression; human AML cell lines show immunoreactivity for both SP and the NK-1R (it is overexpressed: the truncated isoform is more expressed than the full-length form) and, via this receptor, SP and NK-1R antagonists (aprepitant, in a concentration-dependent manner) respectively exert a proliferative action or an antileukemic effect (apoptotic mechanisms are triggered by promoting oxidative stress via mitochondrial Ca⁺⁺ overload). Aprepitant inhibits the formation of AML cell colonies and, in combination with chemotherapeutic drugs, is more effective in inducing cytotoxic effects and AML cell growth blockade. NK-1R antagonists also exert an antinociceptive effect in myeloid leukemia-induced bone pain. The antitumor effect of aprepitant is diminished when the NF-κB pathway is overactivated and the damage induced by aprepitant in cancer cells is higher than that exerted in non-cancer cells. Thus, the SP/NK-1R system is involved in AML, and aprepitant is a promising antitumor strategy against this hematological malignancy. In this review, the involvement of this system in solid and non-solid tumors (in particular in AML) is updated and the use of aprepitant as an anti-leukemic strategy for the treatment of AML is also mentioned (a dose of aprepitant (>20 mg/kg/day) for a period of time according to the response to treatment is suggested). Aprepitant is currently used in clinical practice as an anti-nausea medication.

Neurokinin-1 Receptor Antagonists as Anticancer Drugs

Background::

Human tumor cells lines and tumor samples overexpress the neurokinin-1 receptor (NK-1R). Substance P (SP), after binding to NK-1Rs, induces tumor cell proliferation, an antiapoptotic effect and promotes angiogenesis and the migration of cancer cells for invasion and metastasis.

Methods: :

In contrast, NK-1R antagonists block the previous pathophysiological actions mediated by SP. These antagonists promote the death of tumor cells by apoptosis. Peptide and non-peptide NK-1R antagonists have been reported.

Results: :

Peptide NK-1R antagonists show chemical modifications of the SP molecule (L-amino acids being replaced by D-amino acids), whereas non-peptide NK-1R antagonists include numerous compounds with different chemical compositions while showing similar stereochemical features (affinity for the NK- 1R). Currently, there are more than 300 NK-1R antagonists.

Conclusion::

In combination therapy with classic cytostatics, NK-1R antagonists have additive or synergic effects and minimize the side-effects of cytostatics. The effect of NK-1R antagonists as broad-spectrum anticancer drugs is reviewed and the use of these antagonists for the treatment of cancer is suggested.

Sidedness of Colorectal Cancer Impacts Risk of Second Primary Gastrointestinal Malignancy

INTRODUCTION

A history of colorectal cancer (CRC) increases the risk of subsequent gastrointestinal (GI) cancer. Cancers of the right colon, left colon, and rectum differ according to molecular profiles, responses to treatment, and outcomes.

OBJECTIVE

The purpose of this study was to determine if CRC location is associated with differential risk for secondary primary GI malignancy.

METHODS

A retrospective cohort of adults with CRC was compiled using the Surveillance, Epidemiology, and End Results database (1973-2015). Standardized incidence ratios (SIRs) for second primary GI malignancies were compared based on location of the index CRC (right colon, left colon, or rectum).

RESULTS

The cohort included 281,413 adults with CRC (30.3% right, 35.3% left, 34.3% rectum). With a median 4.9-year follow-up, 12,064 (4.3%) patients developed a second primary GI malignancy (64% CRC, 36% non-CRC). Those with CRC at any location had higher than expected incidences of small intestine, bile duct, and other CRCs, and lower incidences of liver and gallbladder cancer. The SIR for small intestinal cancer was higher after right colon cancer than after left colon or rectal cancer. The esophageal cancer SIR was higher after left colon cancer. Pancreas cancer was higher than expected for right colon cancer, but lower for left colon and rectal cancer.

CONCLUSION

The location of CRC leads to differences in the incidence and location of second primary GI malignancies and may be related to similarities in the associated carcinogenesis and molecular pathways or response to treatment. CRC location not only impacts treatment response and outcomes, but should also be considered during subsequent surveillance.

A Simple and Highly Specific MassARRAY-Based Stool DNA Assay to Prioritize Follow-up Decisions in Fecal Immunochemical Test-Positive Individuals

BACKGROUND

Seventy-five percent of fecal immunochemical test (FIT)-positive individuals are false positives and undergo unnecessary colonoscopies. Here, we established a stool DNA (sDNA) test that uses the Single Allele Base Extension Reaction (SABER) MassARRAY platform to improve the accuracy of FIT-based CRC detection.

METHODS

Twenty-one variants in five CRC-associated genes were selected for the sDNA panel. Cell line DNA and matched mutation-confirmed tissue and stool samples from 34 patients were used for accuracy assessment (cohort 1). The clinical performance of the sDNA assay was further evaluated in 101 independent FIT-positive stool samples (cohort 2).

RESULTS

In cohort 1, we obtained a 62% mutation concordance rate in paired tissue and stool samples of the CRC group, regardless of the FIT status. In cohort 2, 100% specificity in normal controls with positive FIT results was observed. By weighting the FIT value and the presence of a given variant type in stool and then summing the two scores, we found that a one-increment increase in the score was associated with a 4.538-fold risk (95% CI = 2.121⁻9.309) for malignancy in the FIT-positive setting.

CONCLUSIONS

Our highly specific sDNA assay can help prioritize the most at-risk FIT-positive persons to receive prompt colonoscopic confirmation of CRC.

Intestinal bacteria detected in cancer and adjacent tissue from patients with colorectal cancer

Intestinal bacteria are symbiotic microbiota within the human gut and are implicated in the occurrence and development of colorectal cancer (CRC). The current study investigated the changes in bacterial composition prior to and following surgery, as well as the differences in the bacterial community structure between cancer tissue and adjacent normal tissue. The diversity of the bacterial community and the composition of the bacteria were assessed. In addition, phylogenetic analysis and principle component analysis (PCA) were performed. The results revealed that cancer tissue and adjacent normal tissue exhibited similar bacterial compositions. However, a significant difference was identified in the composition of intestinal bacteria in stool samples collected from patients following surgery compared with stool samples collected prior to surgery. Each patient had their own unique intestinal bacterial community, likely due to a number of factors, including diet, genetic factors and health status. In addition, phylogenetic trees revealed that the most abundant operational taxonomic unit, 0001, was associated with Escherichia coli in all samples. Finally, PCA suggested that the bacterial community structure in all patient stools was similar following surgery. The current study provides information regarding the diversity of the intestinal bacterial community of patients with CRC and provides a basis for postoperative intestinal assessments.

Roles for selenium and selenoprotein P in the development, progression, and prevention of intestinal disease

Selenium (Se) is a micronutrient essential to human health, the function of which is mediated in part by incorporation into a class of proteins known as selenoproteins (SePs). As many SePs serve antioxidant functions, Se has long been postulated to protect against inflammation and cancer development in the gut by attenuating oxidative stress. Indeed, numerous studies over the years have correlated Se levels with incidence and severity of intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). Similar results have been obtained with the Se transport protein, selenoprotein P (SELENOP), which is decreased in the plasma of both IBD and CRC patients. While animal models further suggest that decreases in Se or SELENOP augment colitis and intestinal tumorigenesis, large-scale clinical trials have yet to show a protective effect in patient populations. In this review, we discuss the function of Se and SELENOP in intestinal diseases and how research into these mechanisms may impact patient treatment.

Targeted sequencing of 36 known or putative colorectal cancer susceptibility genes

BACKGROUND

Mutations in several genes predispose to colorectal cancer. Genetic testing for hereditary colorectal cancer syndromes was previously limited to single gene tests; thus, only a very limited number of genes were tested, and rarely those infrequently mutated in colorectal cancer. Next-generation sequencing technologies have made it possible to sequencing panels of genes known and suspected to influence colorectal cancer susceptibility.

METHODS

Targeted sequencing of 36 known or putative CRC susceptibility genes was conducted for 1231 CRC cases from five subsets: (1) Familial Colorectal Cancer Type X (n = 153); (2) CRC unselected by tumor immunohistochemical or microsatellite stability testing (n = 548); (3) young onset (age <50 years) (n = 333); (4) proficient mismatch repair (MMR) in cases diagnosed at ≥50 years (n = 68); and (5) deficient MMR CRCs with no germline mutations in MLH1, MSH2, MSH6, or PMS2 (n = 129). Ninety-three unaffected controls were also sequenced.

RESULTS

Overall, 29 nonsense, 43 frame-shift, 13 splice site, six initiator codon variants, one stop codon, 12 exonic deletions, 658 missense, and 17 indels were identified. Missense variants were reviewed by genetic counselors to determine pathogenicity; 13 were pathogenic, 61 were not pathogenic, and 584 were variants of uncertain significance. Overall, we identified 92 cases with pathogenic mutations in APC,MLH1,MSH2,MSH6, or multiple pathogenic MUTYH mutations (7.5%). Four cases with intact MMR protein expression by immunohistochemistry carried pathogenic MMR mutations.

CONCLUSIONS

Results across case subsets may help prioritize genes for inclusion in clinical gene panel tests and underscore the issue of variants of uncertain significance both in well-characterized genes and those for which limited experience has accumulated.

Terahertz endoscopic imaging for colorectal cancer detection: Current status and future perspectives

Terahertz (THz) imaging is progressing as a robust platform for myriad applications in the field of security, health, and material science. The THz regime, which comprises wavelengths spanning from microns to millimeters, is non-ionizing and has very low photon energy: Making it inherently safe for biological imaging. Colorectal cancer is one of the most common causes of death in the world, while the conventional screening and standard of care yet relies exclusively on the physician's experience. Researchers have been working on the development of a flexible THz endoscope, as a potential tool to aid in colorectal cancer screening. This involves building a single-channel THz endoscope, and profiling the THz response from colorectal tissue, and demonstrating endogenous contrast levels between normal and diseased tissue when imaging in reflection modality. The current level of contrast provided by the prototype THz endoscopic system represents a significant step towards clinical endoscopic application of THz technology for in-vivo colorectal cancer screening. The aim of this paper is to provide a short review of the recent advances in THz endoscopic technology and cancer imaging. In particular, the potential of single-channel THz endoscopic imaging for colonic cancer screening will be highlighted.

Tumour-associated and non-tumour-associated microbiota in colorectal cancer

OBJECTIVE

A signature that unifies the colorectal cancer (CRC) microbiota across multiple studies has not been identified. In addition to methodological variance, heterogeneity may be caused by both microbial and host response differences, which was addressed in this study.

DESIGN

We prospectively studied the colonic microbiota and the expression of specific host response genes using faecal and mucosal samples ('ON' and 'OFF' the tumour, proximal and distal) from 59 patients undergoing surgery for CRC, 21 individuals with polyps and 56 healthy controls. Microbiota composition was determined by 16S rRNA amplicon sequencing; expression of host genes involved in CRC progression and immune response was quantified by real-time quantitative PCR.

RESULTS

The microbiota of patients with CRC differed from that of controls, but alterations were not restricted to the cancerous tissue. Differences between distal and proximal cancers were detected and faecal microbiota only partially reflected mucosal microbiota in CRC. Patients with CRC can be stratified based on higher level structures of mucosal-associated bacterial co-abundance groups (CAGs) that resemble the previously formulated concept of enterotypes. Of these, Bacteroidetes Cluster 1 and Firmicutes Cluster 1 were in decreased abundance in CRC mucosa, whereas Bacteroidetes Cluster 2, Firmicutes Cluster 2, Pathogen Cluster and Prevotella Cluster showed increased abundance in CRC mucosa. CRC-associated CAGs were differentially correlated with the expression of host immunoinflammatory response genes.

CONCLUSIONS

CRC-associated microbiota profiles differ from those in healthy subjects and are linked with distinct mucosal gene-expression profiles. Compositional alterations in the microbiota are not restricted to cancerous tissue and differ between distal and proximal cancers.

New frontiers in the treatment of colorectal cancer: Autophagy and the unfolded protein response as promising targets

Colorectal cancer (CRC), despite numerous therapeutic and screening attempts, still remains a major life-threatening malignancy. CRC etiology entails both genetic and environmental factors. Macroautophagy/autophagy and the unfolded protein response (UPR) are fundamental mechanisms involved in the regulation of cellular responses to environmental and genetic stresses. Both pathways are interconnected and regulate cellular responses to apoptotic stimuli. In this review, we address the epidemiology and risk factors of CRC, including genetic mutations leading to the occurrence of the disease. Next, we discuss mutations of genes related to autophagy and the UPR in CRC. Then, we discuss how autophagy and the UPR are involved in the regulation of CRC and how they associate with obesity and inflammatory responses in CRC. Finally, we provide perspectives for the modulation of autophagy and the UPR as new therapeutic options for CRC treatment.

A metagenomic study of the preventive effect of Lactobacillus rhamnosus GG on intestinal polyp formation in ApcMin/+ mice

AIMS

To investigate the in vivo effects of Lactobacillus rhamnosus GG (LGG) on intestinal polyp development and the interaction between this single-organism probiotic and the gut microbiota therein.

METHODS AND RESULTS

The Apc^Min/+ mouse model was used to study the potential preventive effect of LGG on intestinal polyposis, while shotgun metagenomic sequencing was employed to characterize both taxonomic and functional changes within the gut microbial community. We found that the progression of intestinal polyps in the control group altered the community functional profile remarkably despite small variation in the taxonomic diversity. In comparison, the consumption of LGG helped maintain the overall functional potential and taxonomic profile in the resident microbes, thereby leading to a 25% decrease of total polyp counts. Furthermore, we found that LGG enriched those microbes or microbial activities related to short-chain fatty acid production (e.g. Roseburia and Coprococcus), as well as suppressed the ones that can lead to inflammation (e.g. Bilophila wadsworthia).

CONCLUSIONS

Our study using shotgun metagenomics highlights how single probiotic LGG may exert its beneficial effects and decrease polyp formation in mice by maintaining gut microbial functionality.

SIGNIFICANCE AND IMPACT OF THE STUDY

This probiotic intervention targeting microbiota may be used in conjugation with other dietary supplements or drugs as part of prevention strategies for early-stage colon cancer, after further clinical validations in human.

The genetic heterogeneity of colorectal cancer predisposition - guidelines for gene discovery

BACKGROUND

Colorectal cancer (CRC) is a cumulative term applied to a clinically and genetically heterogeneous group of neoplasms that occur in the bowel. Based on twin studies, up to 45 % of the CRC cases may involve a heritable component. Yet, only in 5-10 % of these cases high-penetrant germline mutations are found (e.g. mutations in APC and DNA mismatch repair genes) that result in a familial aggregation and/or an early onset of the disease. Genome-wide association studies have revealed that another ~5 % of the CRC cases may be explained by a cumulative effect of low-penetrant risk factors. Recent attempts to identify novel genetic factors using whole exome and whole genome sequencing has proven to be difficult since the remaining, yet to be discovered, high penetrant CRC predisposing genes appear to be rare. In addition, most of the moderately penetrant candidate genes identified so far have not been confirmed in independent cohorts. Based on literature examples, we here discuss how careful patient and cohort selection, candidate gene and variant selection, and corroborative evidence may be employed to facilitate the discovery of novel CRC predisposing genes.

CONCLUSIONS

The picture emerges that the genetic predisposition to CRC is heterogeneous, involving complex interplays between common and rare (inter)genic variants with different penetrances. It is anticipated, however, that the use of large clinically well-defined patient and control datasets, together with improved functional and technical possibilities, will yield enough power to unravel this complex interplay and to generate accurate individualized estimates for the risk to develop CRC.

Adenomas as a risk factor in familial colorectal cancer: implications for screening and surveillance in the UK

Colorectal cancer (CRC) develops from normal epithelium, through dysplastic adenoma to invasive carcinoma. In addition to familial adenomatous polyposis and Lynch syndrome, approximately 10-35% of CRCs are familial in nature. CRC screening and surveillance programmes are based on an understanding of the natural history of polyps and rely on the ability to remove premalignant lesions endoscopically before they are capable of developing invasion. There are, however, significant differences in these guidelines between the UK and the USA in relation to the weight attributed to a family history of polyps. Here, using publicly available national data sets, we show that these differences in guidelines unexpectedly generate inadequate screening recommendations for second-degree relatives of patients with CRC in the UK. We validate our simple mathematical modelling of the clinical problem on a regional data set as well as previously published study data to demonstrate the correct interpretation. We further discuss the implications of a family history of adenoma formation in the current climate of the Bowel Cancer Screening Programme and suggest a re-evaluation of the UK guidelines in the light of this developing issue.

A Risk Prediction Model for Sporadic CRC Based on Routine Lab Results

BACKGROUND

Current risk scores for colorectal cancer (CRC) are based on demographic and behavioral factors and have limited predictive values.

AIM

To develop a novel risk prediction model for sporadic CRC using clinical and laboratory data in electronic medical records.

METHODS

We conducted a nested case-control study in a UK primary care database. Cases included those with a diagnostic code of CRC, aged 50-85. Each case was matched with four controls using incidence density sampling. CRC predictors were examined using univariate conditional logistic regression. Variables with p value <0.25 in the univariate analysis were further evaluated in multivariate models using backward elimination. Discrimination was assessed using receiver operating curve. Calibration was evaluated using the McFadden's R2. Net reclassification index (NRI) associated with incorporation of laboratory results was calculated. Results were internally validated.

RESULTS

A model similar to existing CRC prediction models which included age, sex, height, obesity, ever smoking, alcohol dependence, and previous screening colonoscopy had an AUC of 0.58 (0.57-0.59) with poor goodness of fit. A laboratory-based model including hematocrit, MCV, lymphocytes, and neutrophil-lymphocyte ratio (NLR) had an AUC of 0.76 (0.76-0.77) and a McFadden's R2 of 0.21 with a NRI of 47.6 %. A combined model including sex, hemoglobin, MCV, white blood cells, platelets, NLR, and oral hypoglycemic use had an AUC of 0.80 (0.79-0.81) with a McFadden's R2 of 0.27 and a NRI of 60.7 %. Similar results were shown in an internal validation set.

CONCLUSION

A laboratory-based risk model had good predictive power for sporadic CRC risk.

Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Background/Aims

The efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.

Methods

Among patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.

Results

Overall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.

Conclusions

Cautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy.

Population-based assessment of the outcomes in patients with postcolonoscopy colorectal cancers

OBJECTIVE

The potential for cancers to not be detected on colonoscopy is increasingly recognised, but little is known about patient outcomes. The objective of this study was to assess the outcomes of patients diagnosed with postcolonoscopy colorectal cancers (PCCRCs).

DESIGN

We conducted a population-based retrospective cohort study, including all patients diagnosed with colorectal cancer (CRC) in Ontario, Canada from 2003 to 2009. Patients were categorised into three groups: DETECTED (diagnosed within 6 months of first colonoscopy), PCCRC (diagnosed 6-36 months after first colonoscopy) or NOSCOPE (no colonoscopy within 36 months of diagnosis). Univariate and multivariable analyses were conducted to study overall survival, surgical treatment, emergency presentation and surgical complications.

RESULTS

Overall, 45 104 patients were included, with 2804 being classified as having a PCCRC. Compared with the DETECTED group, PCCRC was associated with a significantly higher likelihood of stage IV disease (17.2% vs 12.9%), worse overall survival (5 year OS: 60.8% vs 68.3%, p<0.0001; adjusted HR: 1.25, 95% CI 1.17 to 1.32, p<0.0001), a higher likelihood of emergency presentation (OR: 2.86, 95% CI 2.56 to 3.13, p<0.001) and lower likelihood of surgical resection (OR: 0.61, 95% CI 0.55 to 0.67, p<0.001). However, patients with PCCRC had significantly better outcomes than those in the NOSCOPE group (stage IV: 37.1%, 5 year OS: 38.9%)

CONCLUSIONS

Compared with CRC detected by colonoscopy, PCCRCs are associated with a higher risk of emergent presentation, a lower likelihood of surgical resection and most notably, significantly worse oncological outcomes. However, they have better outcomes than patients with no recent colonoscopy.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

How to improve colon cancer screening rates

Colorectal carcinoma is a common cause of death throughout the world and may be prevented by routine control, which can detect precancerous neoplasms and early cancers before they undergo malignant transformation or metastasis. Three strategies may improve colon cancer screening rates: convince the population about the importance of undergoing a screening test; achieve higher efficacy in standard screening tests and make them more available to the community and develop new more sensitive and efficacious screening methods and make them available as routine tests. In this light, the present study seeks to review these three means through which to increase colon cancer screening rates.

Wireless capsule endoscopy in adolescents with familial adenomatous polyposis

Aims and background

Guidelines for surveillance in patients with familial adenomatous polyposis (FAP) recommend mutation carriers to undergo periodic colorectal examination starting in the early teens. Performing colonoscopy in children may lead to complications. Wireless capsule endoscopy (WCE) has been introduced recently to evaluate both the upper and lower gastrointestinal tract, and seems suitable as a first screening examination for adolescents. The aim of this study was to evaluate the pros and cons of WCE.

Methods

This was a retrospective review of a single institution database of adolescent patients with FAP identified through the Hereditary Colorectal Tumor Registry between 2007 and 2013. The main outcomes were identification of upper and lower gastrointestinal tract polyps, tolerance of the examination, and number and size of polyps.

Results

Of 46 adolescent patients with FAP, 14 (30.4%) patients carrying adenomatous polyposis coli gene ( APC) mutation, 6 male and 8 female, age (median, range) 12 (10-17) years, body mass index 19 (13-24), underwent WCE as first screening examination. The examination was completed in 13 patients (93.3%). Wireless capsule endoscopy identified the duodenal papilla in 4 patients and colonic and rectal polyps in all 13 patients. In 7 patients, fewer than 25 polyps were identified. No complications were recorded related to the use of the video capsule.

Conclusions

Wireless capsule endoscopy is feasible and well-tolerated as a first screening examination in adolescent patients. It cannot be used as alternative to the colonoscopy, but could improve compliance with colonoscopy, and increase early adherence to a surveillance program.

Genetics, diagnosis and management of colorectal cancer (Review)

Colorectal cancer (CRC) is the third most common type of cancer worldwide and a leading cause of cancer death. Surgery represents the mainstay of treatment in early cases but often patients are primarily diagnosed in an advanced stage of disease and sometimes also distant metastases are present. Neoadjuvant therapy is therefore needed but drug resistance may influence response and concur to recurrent disease. At molecular level, it is a very heterogeneous group of diseases with about 30% of hereditary or familial cases. During colorectal adenocarcinomas development, epithelial cells from gastrointestinal trait acquire sequential genetic and epigenetic mutations in specific oncogenes and/or tumour suppressor genes, causing CRC onset, progression and metastasis. Molecular characterization of cancer associated mutations gives valuable information about disease prognosis and response to the therapy. Very early diagnosis and personalized care, as well as a better knowledge of molecular basis of its onset and progression, are therefore crucial to obtain a cure of CRC. In this review, we describe updated genetics, current diagnosis and management of CRC pointing out the extreme need for a multidisciplinary approach to achieve the best results in patient outcomes.

Complete resection of colorectal adenomas: what are the important factors in fellow training?

BACKGROUND

The complete removal of adenomatous polyps is important for reducing interval cancer after colonoscopy.

AIMS

To identify factors affecting the completeness of colonoscopic polypectomies and to evaluate the experience level of fellows who achieve competence compared with that of experts.

METHODS

Medical records of 1,860 patients who underwent at least one polypectomy for an adenomatous polyp at Seoul National University Hospital between March 2011 and February 2013 were retrospectively reviewed. A total of 3,469 adenomatous polyps were included. The lateral and deep margins of the resected polyps were evaluated to check the resection completeness.

RESULTS

Of the 3,469 adenomatous polyps, 1,389 (40.0 %) were removed by two experts and 2,080 (60.0 %) were removed by seven fellows. In the expert-treated group, larger size [odds ratio (OR) 2.81 for ≥20 mm, 95 % confidence interval (CI) 1.64-4.84, P < 0.001] and right-sided location (OR 1.31, 95 % CI 1.05-1.63, P = 0.019) were associated with incomplete resection. In the fellow-treated group, not only polyp characteristics [right-sided location (OR 1.41, 95 % CI 1.18-1.69, P < 0.001)], but also the cumulative number of procedures was also related to resection completeness. After 300 polypectomies, the complete resection rate of the fellows was comparable to that of the experts.

CONCLUSIONS

In the fellow-treated group, the level of procedure experience was closely associated with the polypectomy outcomes. Meticulous attention is critical to ensure the completeness of polypectomies performed by trainee endoscopists during the training program.

The prevalence of small intestinal polyps in patients with familial adenomatous polyposis: a prospective capsule endoscopy study

Familial adenomatous polyposis (FAP) is a genetic disorder in which multiple colorectal polyps and cancers develop. However, the prevalence of small intestinal tumors in patients with FAP remains unclear. We elucidated the prevalence of polyps in the small intestine and duodenum using capsule endoscopy (CE). Patients with FAP receiving a periodic screening colonoscopy at Kyoundo Hospital were encouraged to participate in the study. All study participants underwent esophagogastroduodenoscopy (EGD) within 2 weeks before CE. Outcome measurements were the prevalence of duodenal polyps (DP) and small intestinal polyp (SIP), detectability of the ampulla of Vater, and concordance of the duodenal findings between CE and EGD. Twenty-three patients (mean age, 47 years; 15 males) were enrolled in the study. CE showed DPs in 11 patients (52%) and SIPs in nine patients (43 %). The mean numbers of DPs and SIPs was 11.5 ± 6.2 and 11.9 ± 10.9, respectively. SIPs were more often detected in patients with DPs versus those without (62 vs. 13%, P = 0.07). The ampulla of Vater was observed by CE in four patients (21%). EGD showed DPs in 13 patients (62%). EGD missed DPs in two of 11 patients with DPs detected by CE. EGD found DPs in four of 10 patients without DPs using CE. The kappa index was 0.422. Patients with FAP have a high prevalence of polyps in the small intestine. Although the clinical significance of small intestinal polyps remains unclear, patients with FAP seem to be good candidates for CE.

ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes

This guideline presents recommendations for the management of patients with hereditary gastrointestinal cancer syndromes. The initial assessment is the collection of a family history of cancers and premalignant gastrointestinal conditions and should provide enough information to develop a preliminary determination of the risk of a familial predisposition to cancer. Age at diagnosis and lineage (maternal and/or paternal) should be documented for all diagnoses, especially in first- and second-degree relatives. When indicated, genetic testing for a germline mutation should be done on the most informative candidate(s) identified through the family history evaluation and/or tumor analysis to confirm a diagnosis and allow for predictive testing of at-risk relatives. Genetic testing should be conducted in the context of pre- and post-test genetic counseling to ensure the patient's informed decision making. Patients who meet clinical criteria for a syndrome as well as those with identified pathogenic germline mutations should receive appropriate surveillance measures in order to minimize their overall risk of developing syndrome-specific cancers. This guideline specifically discusses genetic testing and management of Lynch syndrome, familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, serrated (hyperplastic) polyposis syndrome, hereditary pancreatic cancer, and hereditary gastric cancer.

The utility of Apc-mutant rats in modeling human colon cancer

Prior to the advent of genetic engineering in the mouse, the rat was the model of choice for investigating the etiology of cancer. Now, recent advances in the manipulation of the rat genome, combined with a growing recognition of the physiological differences between mice and rats, have reignited interest in the rat as a model of human cancer. Two recently developed rat models, the polyposis in the rat colon (Pirc) and Kyoto Apc Delta (KAD) strains, each carry mutations in the intestinal-cancer-associated adenomatous polyposis coli (Apc) gene. In contrast to mouse models carrying Apc mutations, in which cancers develop mainly in the small intestine rather than in the colon and there is no gender bias, these rat models exhibit colonic predisposition and gender-specific susceptibility, as seen in human colon cancer. The rat also provides other experimental resources as a model organism that are not provided by the mouse: the structure of its chromosomes facilitates the analysis of genomic events, the size of its colon permits longitudinal analysis of tumor growth, and the size of biological samples from the animal facilitates multiplexed molecular analyses of the tumor and its host. Thus, the underlying biology and experimental resources of these rat models provide important avenues for investigation. We anticipate that advances in disease modeling in the rat will synergize with resources that are being developed in the mouse to provide a deeper understanding of human colon cancer.

Report of a Novel Mutation in MLH1 Gene in a Hispanic Family from Puerto Rico Fulfilling Classic Amsterdam Criteria for Lynch Syndrome

In Puerto Rico, colorectal cancer (CRC) represents the second leading cause of cancer in men and women. Familial CRC accounts for 10–15% of the total CRC cases, while Lynch syndrome accounts for approximately 2–4% of cases. Limited information is available about the prevalence, clinical manifestations, and genetic mutations of hereditary CRC in US Hispanic individuals. In this paper we report a novel mutation in the hMLH1 gene in a Puerto Rican Hispanic family with Lynch syndrome recruited through the Puerto Rico Familial Colorectal Cancer Registry (PURIFICAR). Our proband was identified by applying Amsterdam and Bethesda criteria for Lynch syndrome, analysis of protein expression by immunohistochemistry, and genetic sequencing of the mismatch repair genes. A novel mutation at c.2044_2045 in hMLH1 consisting of the deletion of two consecutive nucleotides (AT) at exon 18 was identified. This deletion causes a frameshift in the protein coding sequence at p.682 resulting in premature termination and a truncated MLH1 protein. To our knowledge, this mutation has not been previously reported in the literature. The detection of this novel mutation in MLH1 further emphasizes the need for genetic testing in at-risk patients for hereditary CRC from various ethnic and racial backgrounds.