Impact of the COVID-19 pandemic on the performance of endoscopy in the Tohoku region of Japan

Objectives

The whole picture of the disturbance in endoscopy performance caused by the coronavirus disease 2019 (COVID-19) pandemic in Japan remains to be clarified. Therefore, the Japan Gastroenterological Endoscopy Society-Tohoku conducted this questionnaire survey in Tohoku region of Japan.

Methods

A questionnaire on the number of diagnostic endoscopy procedures and resulting diagnosed cancers in 2019 and 2020 was sent to all guidance/guidance cooperation hospitals in the Japan Gastroenterological Endoscopy Society who worked in the Tohoku region. The percentage change was calculated by comparing the numbers in 2020 with those in 2019 (the pre-COVID-19 period).

Results

Among the applicable 89 guidance/guidance cooperation hospitals, 83 (94%) returned the questionnaire. The number of endoscopy procedures promptly decreased to the nadir in April and May 2020 (during the first state of emergency in Japan); however, it recovered relatively quickly, within a few months after the state of emergency was lifted. Consequently, the annual reduction in the number of endoscopy procedures in 2020 (in comparison to 2019) was 10.1% for esophagogastroduodenoscopy and 7.9% for colonoscopy. The reduction in the number of diagnostic endoscopy procedures led to a 5.5% reduction in esophagogastric cancer and 2.7% in colorectal cancer.

Conclusions

This is the most comprehensive survey on the impact of the COVID-19 pandemic on the performance of endoscopy and the resulting diagnosis of cancer in Japan. Understanding the magnitude of the decline in endoscopic examinations and cancer detection due to the pandemic is critical to understanding how many people will ultimately be affected and establishing a strategy for providing endoscopy during national emergencies.

Modes of Interactions with DNA/HSA Biomolecules and Comparative Cytotoxic Studies of Newly Synthesized Mononuclear Zinc(II) and Heteronuclear Platinum(II)/Zinc(II) Complexes toward Colorectal Cancer Cells

A series of mono- and heteronuclear platinum(II) and zinc(II) complexes with 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine ligand were synthesized and characterized. The DNA and protein binding properties of [ZnCl2(terpytBu)] (C1), [{cis-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C2), [{trans-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C3), [{cis-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C4) and [{trans-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C5) (where terpytBu = 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine), were investigated by electronic absorption, fluorescence spectroscopic, and molecular docking methods. Complexes featuring transplatin exhibited lower Kb and Ksv constant values compared to cisplatin analogs. The lowest Ksv value belonged to complex C1, while C4 exhibited the highest. Molecular docking studies reveal that the binding of complex C1 to DNA is due to van der Waals forces, while that of C2-C5 is due to conventional hydrogen bonds and van der Waals forces. The tested complexes exhibited variable cytotoxicity toward mouse colorectal carcinoma (CT26), human colorectal carcinoma (HCT116 and SW480), and non-cancerous mouse mesenchymal stem cells (mMSC). Particularly, the mononuclear C1 complex showed pronounced selectivity toward cancer cells over non-cancerous mMSC. The C1 complex notably induced apoptosis in CT26 cells, effectively arrested the cell cycle in the G0/G1 phase, and selectively down-regulated Cyclin D.

The Roles and Interactions of Porphyromonas gingivalis and Fusobacterium nucleatum in Oral and Gastrointestinal Carcinogenesis: A Narrative Review

Epidemiological studies have spotlighted the intricate relationship between individual oral bacteria and tumor occurrence. Porphyromonas gingivalis and Fusobacteria nucleatum, which are known periodontal pathogens, have emerged as extensively studied participants with potential pathogenic abilities in carcinogenesis. However, the complex dynamics arising from interactions between these two pathogens were less addressed. This narrative review aims to summarize the current knowledge on the prevalence and mechanism implications of P. gingivalis and F. nucleatum in the carcinogenesis of oral squamous cell carcinoma (OSCC), colorectal cancer (CRC), and pancreatic ductal adenocarcinoma (PDAC). In particular, it explores the clinical and experimental evidence on the interplay between P. gingivalis and F. nucleatum in affecting oral and gastrointestinal carcinogenesis. P. gingivalis and F. nucleatum, which are recognized as keystone or bridging bacteria, were identified in multiple clinical studies simultaneously. The prevalence of both bacteria species correlated with cancer development progression, emphasizing the potential impact of the collaboration. Regrettably, there was insufficient experimental evidence to demonstrate the synergistic function. We further propose a hypothesis to elucidate the underlying mechanisms, offering a promising avenue for future research in this dynamic and evolving field.

Assessment of the DNA Mismatch Repair System Is Crucial in Colorectal Cancers Necessitating Adjuvant Treatment: A Propensity Score-Matched and Win Ratio Analysis

A deficient DNA mismatch repair (MMR) system is identified in a non-negligible part of sporadic colorectal cancers (CRCs), and its prognostic value remains controversial. High tumor mutational burden, along with a poor response to conventional chemotherapy and excellent results from immunotherapy, are the main features of this subset. The aim of this study was to evaluate the predictive value of DNA MMR system status for its best treatment. Four hundred and three CRC patients, operated on from 2014 to 2021 and not treated with immunotherapy, entered this study. Immunohistochemistry and polymerase chain reaction, as appropriate, were used to unequivocally group specimens into microsatellite stable (MSS) and instable (MSI) tumors. The win-ratio approach was utilized to compare composite outcomes. MSI tumors accounted for 12.9% of all series. The right tumor location represented the most important factor related to MSI. The status of the DNA MMR system did not appear to correlate with outcome in early-stage CRCs not requiring adjuvant treatment; in advanced stages undergoing conventional chemotherapy, MSI tumors showed significantly poorer overall and disease-free survival rates and the highest win ratio instead. The determination of DNA MMR status is crucial to recommending correct management. There is clear evidence that instable CRCs needing adjuvant therapy should undergo appropriate treatments.

Disparities in Cancer Incidence across Income Levels in South Korea

BACKGROUND

Recent nationwide studies of disparities in cancer incidence by income are scarce in Korea. This study investigated such disparities in cancer incidence and the stage at cancer diagnosis across income groups in Korea.

METHODS

This study utilized data from a national cancer database, specifically focusing on cases recorded in the year 2018. Income levels were categorized into quintiles according to the insurance premium paid in addition to the Medicaid benefit. The slope index of inequality (SII) and relative index of inequality (RII) were used to measure absolute and relative differences in cancer incidence by income. A multivariable logistic regression was performed to estimate the risk of a distant stage at cancer diagnosis.

RESULTS

The total number of cases of incident cancer was 223,371 (men: 116,320, women: 107,051) with shares of the total of 29.5% (5Q), 20.4% (4Q), 16.0% (3Q), 13.5% (2Q), 15.6% (1Q), and 5% (Medicaid). The most common cancer type was thyroid cancer, followed by gastric and colorectal cancers. The age-standardized incidence rate for all cancers was lowest in the highest income group, but the SII was not statistically significant (SII: -35.7), and the RII was -0.07. Colorectal and cervical cancers had lower incidence rates for higher income groups, while thyroid and prostate cancers had higher incidence rates for higher income groups. The odds ratio for a distant stage at diagnosis for all cancers increased for lower income groups relative to 5Q.

CONCLUSIONS

Disparities in cancer incidence in a Korean population differed by cancer type, and lower income was a significant predictor of a distant stage at diagnosis for cancers overall. These results emphasize the need for further study of the underlying causes of disparities in cancer incidence and the stage at diagnosis, as well as the need for interventions to mitigate these disparities.

Metallothionein Family Proteins as Regulators of Zinc Ions Synergistically Enhance the Anticancer Effect of Cannabidiol in Human Colorectal Cancer Cells

Cannabidiol (CBD) is a chemical obtained from Cannabis sativa; it has therapeutic effects on anxiety and cognition and anti-inflammatory properties. Although pharmacological applications of CBD in many types of tumors have recently been reported, the mechanism of action of CBD is not yet fully understood. In this study, we perform an mRNA-seq analysis to identify the target genes of CBD after determining the cytotoxic concentrations of CBD using an MTT assay. CBD treatment regulated the expression of genes related to DNA repair and cell division, with metallothionein (MT) family genes being identified as having highly increased expression levels induced by CBD. It was also found that the expression levels of MT family genes were decreased in colorectal cancer tissues compared to those in normal tissues, indicating that the downregulation of MT family genes might be highly associated with colorectal tumor progression. A qPCR experiment revealed that the expression levels of MT family genes were increased by CBD. Moreover, MT family genes were regulated by CBD or crude extract but not by other cannabinoids, suggesting that the expression of MT family genes was specifically induced by CBD. A synergistic effect between CBD and MT gene transfection or zinc ion treatment was found. In conclusion, MT family genes as novel target genes could synergistically increase the anticancer activity of CBD by regulating the zinc ions in human colorectal cancer cells.

Colorectal Cancer: Disease Process, Current Treatment Options, and Future Perspectives

Colorectal cancer (CRC) is one of the deadliest malignancies in the US, ranking fourth after lung, prostate, and breast cancers, respectively, in general populations. It continues to be a menace, and the incidence has been projected to more than double by 2035, especially in underdeveloped countries. This review seeks to provide some insights into the disease progression, currently available treatment options and their challenges, and future perspectives. Searches were conducted in the PubMed search engine in the university's online library. The keywords were "Colorectal Cancer" AND "disease process" OR "disease mechanisms" OR "Current Treatment" OR "Prospects". Selection criteria were original articles published primarily during the period of 2013 through 2023. Abstracts, books and documents, and reviews/systematic reviews were filtered out. Of over 490 thousand articles returned, only about 800 met preliminary selection criteria, 200 were reviewed in detail, but 191 met final selection criteria. Fifty-one other articles were used due to cross-referencing. Although recently considered a disease of lifestyle, CRC incidence appears to be rising in countries with low, low-medium, and medium social demographic indices. CRC can affect all parts of the colon and rectum but is more fatal with poor disease outcomes when it is right-sided. The disease progression usually takes between 7-10 years and can be asymptomatic, making early detection and diagnosis difficult. The CRC tumor microenvironment is made up of different types of cells interacting with each other to promote the growth and proliferation of the tumor cells. Significant advancement has been made in the treatment of colorectal cancer. Notable approaches include surgery, chemotherapy, radiation therapy, and cryotherapy. Chemotherapy, including 5-fluorouracil, irinotecan, oxaliplatin, and leucovorin, plays a significant role in the management of CRC that has been diagnosed at advanced stages. Two classes of monoclonal antibody therapies have been approved by the FDA for the treatment of colorectal cancer: the vascular endothelial growth factor (VEGF) inhibitor, e.g., bevacizumab (Avastin®), and the epidermal growth factor receptor (EGFR) inhibitor, e.g., cetuximab (Erbitux®) and panitumumab (Verbitix®). However, many significant problems are still being experienced with these treatments, mainly off-target effects, toxic side effects, and the associated therapeutic failures of small molecular drugs and the rapid loss of efficacy of mAb therapies. Other novel delivery strategies continue to be investigated, including ligand-based targeting of CRC cells.

Transplant Oncology: An Emerging Discipline of Cancer Treatment

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients' survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Transcription factor expression repertoire basis for epigenetic and transcriptional subtypes of colorectal cancers

Colorectal cancers (CRCs) form a heterogenous group classified into epigenetic and transcriptional subtypes. The basis for the epigenetic subtypes, exemplified by varying degrees of promoter DNA hypermethylation, and its relation to the transcriptional subtypes is not well understood. We link cancer-specific transcription factor (TF) expression alterations to methylation alterations near TF-binding sites at promoter and enhancer regions in CRCs and their premalignant precursor lesions to provide mechanistic insights into the origins and evolution of the CRC molecular subtypes. A gradient of TF expression changes forms a basis for the subtypes of abnormal DNA methylation, termed CpG-island promoter DNA methylation phenotypes (CIMPs), in CRCs and other cancers. CIMP is tightly correlated with cancer-specific hypermethylation at enhancers, which we term CpG-enhancer methylation phenotype (CEMP). Coordinated promoter and enhancer methylation appears to be driven by downregulation of TFs with common binding sites at the hypermethylated enhancers and promoters. The altered expression of TFs related to hypermethylator subtypes occurs early during CRC development, detectable in premalignant adenomas. TF-based profiling further identifies patients with worse overall survival. Importantly, altered expression of these TFs discriminates the transcriptome-based consensus molecular subtypes (CMS), thus providing a common basis for CIMP and CMS subtypes.

The Prevalence of Back Pain in Patients Operated on Due to Colorectal Cancer Depending on the Type of Surgical Procedure Performed

PURPOSE

Low back pain presents a serious challenge for numerous medical specialties. The purpose of this study was to assess disability due to low back pain in patients operated on due to colorectal cancer depending on the type of surgery performed.

METHODS

This prospective observational study was carried out in the period of July 2019 through March 2020. Included in the study were patients with colorectal cancer for scheduled surgeries including anterior resection of rectum (AR), laparoscopic anterior resection of rectum (LAR), Hartmann's procedure (HART), or abdominoperineal resection of rectum (APR). The Oswestry Low Back Pain Disability Questionnaire was used as the research tool. The study patients were surveyed at three time points: before surgery, six months after surgery, and one year after surgery.

RESULTS

The analysis of study results revealed that an increase in the degree of disability and functioning impairment occurred in all groups between time points I and II, with the differences being statistically significant (p < 0.05). The inter-group comparative analysis of the total Oswestry questionnaire scores revealed statistically significant differences, with the impairment of function being most severe within the APR group and least severe within the LAR group.

CONCLUSION

The study results showed that low back pain contributes to impaired functioning of patients operated on due to colorectal cancer regardless of the type of procedure performed. A reduction in the degree of disability due to low back pain was observed one year after the procedure in patients having undergone LAR.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

Vaccination-Based Immunoprevention of Colorectal Tumors: A Primer for the Clinician

Colorectal cancer (CRC) continues to be a significant public health problem worldwide. CRC screening programs have reduced the incidence rates of CRCs but still suffer from the problems of missed lesions and interval cancers. Chemopreventive strategies against CRC would benefit high-risk populations but trials testing synthetic and naturally occurring compounds have not yielded a front runner. Immune mechanisms promoting cancer have been modulated to develop immunotherapy for cancer treatment that has revolutionized cancer management, but could also be applied to cancer interception, that is, cancer immunoprevention. Cancer immunoprevention refers to approaches that can enhance the immune system, either directly or by removing natural breaks such as immune checkpoints, to survey and destroy tumor cells. In this primer, we aim to explain the concepts behind vaccine-based cancer immunoprevention. Multiple cancer vaccines have been tried in advanced cancer populations, but most have failed primarily because of an immunosuppressive environment that accompanies advanced cancers. Preventive vaccines in immunocompetent hosts may have a better clinical response compared with therapeutic vaccines in immunosuppressed hosts. The first randomized controlled trial testing the mucin1 vaccine against CRC in the prevention setting has been successfully completed. For the benefit of the clinician, we briefly discuss important concepts related to the workings of preventive vaccines. Prevention with vaccines is a highly attractive approach because of the potential for highly targeted therapy with minimal side effects that could theoretically provide lifelong protection.

Clinical role of CD274 (PD-L1) and CD3+ lymphocytes in predicting high risk in advanced colorectal cancer patients receiving neoadjuvant chemotherapy

In cancer research, the mechanism underlying the immune response to a tumour has been of great interest. In this study, we investigated the role of CD274 (programmed cell death-ligand 1 - PD-L1) and CD3+ tumour-infiltrating lymphocytes (TILs) in the prognosis of advanced colorectal cancer (CRC) patients treated with neoadjuvant chemotherapy. We retrospectively examined primary tumour specimens from stage III/IV CRC patients operated on between 2008 and 2018. We found a significant association between these biomarkers and pT stage (PD-L1, p = 0.020; CD3+TILs, p = 0.025), tumour grade (PD-L1, p = 0.005; CD3+TILs, p = 0.004), positive surgical margin (PD-L1, p = 0.001; CD3+TILs, p = 0.001), MSI (PD-L1, p < 0.001; CD3+TILs, p < 0.001), etc. We also discovered that these biomarkers are independent risk factors for MSI (PD-L1, OR = 1.84 [1.27-4.02], p = 0.003; CD3+TILs, OR = 1.92 [1.31-4.35], p = 0.008). Univariate analysis results revealed that patients with high PD-L1, low CD3+TIL, and both showed poor relapse-free survival (RFS) and poor overall survival (OS) (PD-L1: RFS, p = 0.008 and OS, p = 0.001; CD3+TILs: RFS, p = 0.003 and OS, p = 0.005; PD-L1 and CD3+TILs: RFS, p < 0.001 and OS, p < 0.001). The results of the multivariate analysis showed that the combined use of high PD-L1 and low CD3+TILs was a better predictor of poor RFS and OS (PD-L1 and CD3+TILs: RFS, hazard ratio - HR, = 2.85 [95% CI: 1.36-3.84], p < 0.001); OS, HR = 2.74 [1.32-3.71], p < 0.001). We also found a high PD-L1 parameter as another independent overall and relapse-free survival parameter. Our findings suggest that a combination of high PD-L1 and low CD3+TIL can reliably predict poor survival in CRC patients receiving chemotherapy. Therefore, these biomarkers may be promising for the planning and execution of appropriate targeted therapies.

High prevalence of unusual KRAS, NRAS and BRAF mutations in POLE hypermutated colorectal cancers

Exonucleasic domain POLE (edPOLE) mutations, which are responsible for a hypermutated tumor phenotype, occur in 1–2% of colorectal cancer (CRC) cases. These alterations represent an emerging biomarker for response to immune checkpoint blockade. This study aimed to assess the molecular characteristics of edPOLE‐mutated tumors to facilitate patient screening. Based on opensource data analysis, we compared the prevalence of edPOLE mutations in a control group of unselected CRC patients (n = 222) vs a group enriched for unusual BRAF/RAS mutations (n = 198). Tumor mutational burden (TMB) and immune infiltrate of tumors harboring edPOLE mutations were then analyzed. In total, 420 CRC patients were analyzed: 11 edPOLE‐mutated tumors were identified, most frequently in microsatellite (MMR)‐proficient young (< 70 years) male patients, with left‐sided tumors harboring noncodon 12 KRAS mutation. The prevalence of edPOLE‐mutated tumors in the control vs the experimental screening group was, respectively, 0.45% (n = 1) vs 5.0% (n = 10). Among the 11 edPOLE‐mutated cases, two had a low TMB, three were hypermutated, and six were ultramutated. EdPOLE‐mutated cases had a high CD8⁺ tumor‐infiltrating lymphocyte (TIL) infiltration. These clinicopathological and molecular criteria may help to identify edPOLE mutations associated with a high TMB in CRC, and improve the selection of patients who could benefit from immunotherapy.

The predictive value of vitamin D follow-up and supplementation on recurrence in patients with colorectal cancer

Aim: Vitamin D has a role in carcinogenesis and may have effect on recurrence. Thus, we aim to analyze the prognostic effect of vitamin D levels at beginning and follow-up together with the contribution of vitamin D supplementation on patients with colorectal cancer (CRC). Materials & methods: CRC patients who underwent curative surgery were included. Patients' vitamin D values were assessed under four groups according to baseline and follow-up vitamin D values, and whether vitamin D supplementation was used. Survival distributions were compared for vitamin D groups. Results: Patients with a high follow-up vitamin D level and a high vitamin D level after supplementation presented with better disease-free survival and overall survival than patients with low vitamin D and low vitamin D levels after supplementation. Conclusion: Follow-up vitamin D values seems to be a good predictive biomarker and vitamin D supplementation may have a positive effect on survival.

JAK-STAT core cancer pathway: An integrative cancer interactome analysis

Through a comprehensive review and in silico analysis of reported data on STAT-linked diseases, we analysed the communication pathways and interactome of the seven STATs in major cancer categories and proposed rational targeting approaches for therapeutic intervention to disrupt critical pathways and addictions to hyperactive JAK/STAT in neoplastic states. Although all STATs follow a similar molecular activation pathway, STAT1, STAT2, STAT4 and STAT6 exert specific biological profiles associated with a more restricted pattern of activation by cytokines. STAT3 and STAT5A as well as STAT5B have pleiotropic roles in the body and can act as critical oncogenes that promote many processes involved in cancer development. STAT1, STAT3 and STAT5 also possess tumour suppressive action in certain mutational and cancer type context. Here, we demonstrated member-specific STAT activity in major cancer types. Through systems biology approaches, we found surprising roles for EGFR family members, sex steroid hormone receptor ESR1 interplay with oncogenic STAT function and proposed new drug targeting approaches of oncogenic STAT pathway addiction.

Utility of Cell-Free DNA Detection in Transplant Oncology

Simple Summary

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-liver transplant stages, and evaluate transplant rejection. The use of ctDNA to evaluate transplant rejection has been extensively studied in non-hepatocellular carcinoma (HCC) diseases. Emerging studies have also investigated the use of ctDNA detection in evaluating HCC tumor burden pre-and post-surgery as well as transplant rejection. However, extensive studies still need to be conducted to evaluate the role of ctDNA detection in the medical management of transplant oncology patients.

Abstract

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. A critical concept that must be addressed to ensure the successful application of transplant oncology to patient care is efficient monitoring of tumor burden pre-and post-transplant and transplant rejection. Cell-free DNA (cfDNA) detection has emerged as a vital tool in revolutionizing the management of cancer patients who undergo organ transplantation. The advances in cfDNA technology have provided options to perform a pre-transplant evaluation of minimal residual disease (MRD) and post-transplant evaluation of cancer recurrence and transplant rejection. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-transplant stages, and evaluate transplant rejection.

The Application of Metabolomics in Recent Colorectal Cancer Studies: A State-of-the-Art Review

Simple Summary

Colorectal Cancer (CRC) is one of the leading causes of cancer-related death in the United States. Current diagnosis techniques are either highly invasive or lack sensitivity, suggesting the need for alternative techniques for biomarker detection. Metabolomics represents one such technique with great promise in identifying CRC biomarkers with high sensitivity and specificity, but thus far is rarely employed in a clinical setting. In order to provide a framework for future clinical usage, we characterized dysregulated metabolites across recent literature, identifying metabolites dysregulated across a variety of biospecimens. We additionally put special focus on the interplay of the gut microbiome and perturbed metabolites in CRC. We were able to identify many metabolites showing consistent dysregulation in CRC, demonstrating the value of metabolomics as a promising diagnostic technique.

Abstract

Colorectal cancer (CRC) is a highly prevalent disease with poor prognostic outcomes if not diagnosed in early stages. Current diagnosis techniques are either highly invasive or lack sufficient sensitivity. Thus, identifying diagnostic biomarkers of CRC with high sensitivity and specificity is desirable. Metabolomics represents an analytical profiling technique with great promise in identifying such biomarkers and typically represents a close tie with the phenotype of a specific disease. We thus conducted a systematic review of studies reported from January 2012 to July 2021 relating to the detection of CRC biomarkers through metabolomics to provide a collection of knowledge for future diagnostic development. We identified thirty-seven metabolomics studies characterizing CRC, many of which provided metabolites/metabolic profile-based diagnostic models with high sensitivity and specificity. These studies demonstrated that a great number of metabolites can be differentially regulated in CRC patients compared to healthy controls, adenomatous polyps, or across stages of CRC. Among these metabolite biomarkers, especially dysregulated were certain amino acids, fatty acids, and lysophosphatidylcholines. Additionally, we discussed the contribution of the gut bacterial population to pathogenesis of CRC through their modulation to fecal metabolite pools and summarized the established links in the literature between certain microbial genera and altered metabolite levels in CRC patients. Taken together, we conclude that metabolomics presents itself as a promising and effective method of CRC biomarker detection.

Transplant Oncology: An Evolving Field in Cancer Care

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The application of oncology, transplant medicine, and surgery to improve patients' survival and quality of life is the core of transplant oncology. Hepatobiliary malignancies have been treated by liver transplantation (LT) with significant improved outcome. In addition, as the liver is the most common site of metastasis for colorectal cancer (CRC), patients with CRC who have stable unresectable liver metastases are good candidates for LT, and initial studies have shown improved survival compared to palliative systemic therapy. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years in a stepwise manner; however, they have only been shown to improve patient survival in the setting of limited systemic therapy options. This review illustrates the concept and history of transplant oncology as an evolving field for the management of hepatocellular carcinoma, intrahepatic biliary cancer, and liver-only metastasis of non-hepatobiliary carcinoma. The utility of immunotherapy in the transplant setting is discussed as well as the feasibility of using circulating tumor DNA for surveillance post-transplantation.

Perforated colorectal cancers: clinical outcomes of 18 patients who underwent emergency surgery

Introduction

Although colon cancer perforations are rare among acute abdominal syndromes, it is a clinical picture with high mortality that requires urgent treatment.

Aim

In this study, the clinical results of patients who were operated in emergency conditions due to colorectal cancer perforation were evaluated.

Material and methods

The data of 18 patients treated for colorectal cancer perforation in our clinic between February 2014 and February 2017 were retrospectively reviewed. The following data were evaluated: demographic features of the patients, location of the tumour, metastasis, stage of the tumour, number of lymph nodes dissected, survival, type, and prognosis of the surgery.

Results

Eight (44%) of 18 patients with perforated colon cancers were female and 10 (56%) were male. The mean age was 65.2 (31-104) years. Four of the patients had liver metastasis only, and 5 had multiple metastases. All cases had sudden abdominal pain and acute abdominal clinical findings. Fourteen of the patients underwent full resection, and 4 of them underwent partial resection and trephine stoma (colostomy). Perioperative mortality was not observed. The long-term mortality rate in our study was 77.7% (n = 14), and the operative mortality rate was 44% (n = 8). Additional organ injuries occurred during resection in 2 patients.

Conclusions

Colorectal cancer perforation seen in advanced ages is one of the causes of acute abdominal syndrome, which can be fatal. The general condition of the patient and the size and localization of the perforation should be taken into consideration in the choice of treatment. Curative surgery can also be performed in perforated colorectal cancers. However, partial resection and trephine colostomy should be performed in patients with multiple metastases and poor general condition.

HER2 Overexpression and Mismatch Repair Deficiency are Correlated with Malignancy in Colorectal Cancer

PURPOSE

This study was designed to investigate the correlation between the expression of human epidermal growth factor receptor 2 (HER2), mismatch repair (MMR), and clinicopathological parameters and serum tumor markers in a total of 522 resection samples materials from colorectal cancer (CRC) patients. These data were also used to determine the links between HER2 and MMR expression and prognosis.

METHODS

We conducted a retrospective analysis of the clinical data from 522 CRC patients. Immunohistochemistry (IHC) was used to detect HER2 overexpression and MMR deficiency (dMMR) in tumor specimens which were then correlated with various clinicopathological parameters. Prognostic value for HER2 and MMR expression was then evaluated using the data from 105 CRC patients.

RESULTS

HER2 overexpression was identified in 35.63% of the samples evaluated in this study, while the total dMMR rate was 12.64%. Expression of HER2 and several, MMR proteins (MLH1, MSH-2, MSH-6, and PMS-2) were then correlated with tumor location. HER2 overexpression is significantly associated with increased depth of tumor invasion, lymph node metastasis, distant metastases, pTNM staging, vascular invasion, nerve infiltration, and serum carcinoembryonic antigen (CEA) levels. HER2 overexpression and dMMR increased with advancing clinical stage. In addition, deficiencies in MLH1 and PMS2 correlated with HER2 overexpression. Finally, the prognostic evaluations revealed that HER2 overexpression was closely associated with poorer clinical outcomes.

CONCLUSION

HER2 overexpression is significantly correlated with multiple clinicopathological parameters resulting in a poorer prognosis. Moreover, the prognosis of patients with HER2 overexpression was worse, confirming its significance during disease assessment. In clinical practice, clinicians should pay close attention to the HER2 profile of patients as they may require more extensive clinical intervention. In addition, deficiencies in MLH1, MSH-2, MSH-6, or PMS-2 correlate with tumor location, and MLH1 and PMS2 expression is associated with lymph node metastasis and pTNM stage, suggesting that these may be additional markers in CRC risk assessments.

Predictive and prognostic biomarkers with therapeutic targets in colorectal cancer: A 2021 update on current development, evidence, and recommendation

Although therapeutically actionable molecular alterations are widely distributed across many cancer types, only a handful of them show evidence of clinical utility and are recommended for routine clinical practice in the management of cancers of colon and rectum (CRC). This 2021 update aims to provide a succinct summary on the use of prognostic and/or predictive biomarkers (expanded RAS, BRAF, microsatellite-high [MSI-H] or deficient mismatch repair [dMMR], neurotrophic tyrosine receptor kinase [NTRK] fusion genes, and human epidermal growth factor receptor type II [HER2] gene amplification) associated with CRC. Therapeutic implications of each relevant predictive or prognostic biomarker for patients with CRC are described, along with discussion on new developments on (1) biomarker-driven therapies such as testing of BRAF, MLH1 promoter methylation and MMR germline genes in differentiating sporadic CRC or hereditary conditions such as Lynch syndrome; (2) first-line use of immune checkpoint inhibitors in metastatic CRC; (3) risk stratification and therapy selection based on primary tumor location (left-sided vs. right-sided colon cancer); (3) atypical BRAF mutations; (4) use of EGFR directed therapy in the perioperative oligometastatic disease setting; (5) re-challenge of EGFR directed therapy and (6) personalizing therapy of fluoropyrimidine and irinotecan based on new evidence in pharmacogenomic testing. Data are collected and analyzed from available systematic reviews and meta-analyses of treatments with known therapeutic targets in CRC, which may be associated with predictive and/or prognostic biomarkers. Discussions are presented in an application-based format, with goal to empower pharmacists or other clinicians to gain awareness and understanding in biomarker-driven cancer therapy issues.

Clinicopathological Significances of Tumor-Stroma Ratio (TSR) in Colorectal Cancers: Prognostic Implication of TSR Compared to Hypoxia-Inducible Factor-1α Expression and Microvessel Density

The present study aimed to elucidate the clinicopathological significance and prognostic implications of tumor–stroma ratio (TSR) in colorectal cancers (CRCs). TSRs were investigated in 266 human CRC specimens. The correlations between TSR and clinicopathological characteristics and survival were evaluated. The hypoxia-inducible factor-1α (HIF-1α) immunohistochemical expression of tumor cells and microvessel density (MVD) of stroma were compared between stroma-low and stroma-high subgroups. Results: Stroma-low was found in 185 of 266 CRCs (69.5%). Stroma-low was significantly correlated with less frequent vascular and perineural invasion and distant metastasis than stroma-high. HIF-1α of tumor cells was more highly expressed in the stroma-high subgroup than in the stroma-low subgroup. In addition, MVD was significantly higher in the stroma-high subgroup compared to the stroma-low subgroup. The stroma-low rate was increased considerably in CRCs with a mucinous component and decreased in CRCs with a micropapillary component. There were significant correlations between stroma-low and better overall and recurrence-free survivals. Similar to the literature, we observed that stroma-low was significantly correlated with favorable tumor behaviors and better survival. The microscopic examination of TSR can be useful for predicting the prognosis of CRC patients.

Senescent Tumor Cells Build a Cytokine Shield in Colorectal Cancer

Cellular senescence can either support or inhibit cancer progression. Here, it is shown that intratumoral infiltration of CD8+ T cells is negatively associated with the proportion of senescent tumor cells in colorectal cancer (CRC). Gene expression analysis reveals increased expression of C-X-C motif chemokine ligand 12 (CXCL12) and colony stimulating factor 1 (CSF1) in senescent tumor cells. Senescent tumor cells inhibit CD8+ T cell infiltration by secreting a high concentration of CXCL12, which induces a loss of CXCR4 in T cells that result in impaired directional migration. CSF1 from senescent tumor cells enhance monocyte differentiation into M2 macrophages, which inhibit CD8+ T cell activation. Neutralization of CXCL12/CSF1 increases the effect of anti-PD1 antibody in allograft tumors. Furthermore, inhibition of CXCL12 from senescent tumor cells enhances T cell infiltration and results in reducing the number and size of tumors in azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced CRC. These findings suggest senescent tumor cells generate a cytokine barrier protecting nonsenescent tumor cells from immune attack and provide a new target for overcoming the immunotherapy resistance of CRC.

Human oral microbiome dysbiosis as a novel non-invasive biomarker in detection of colorectal cancer

Background: The oral microbiome may play an important role in colorectal carcinogenesis. However, few studies have investigated the association between oral microbiome and the development of colorectal cancer (CRC). We aimed to investigate whether oral health-colorectal tumor association has an underlying microbial basis, in the quest for novel non-invasive biomarkers for CRC.

Methods: We collected oral swab samples from 161 patients with CRC, 34 patients with colorectal adenoma (CRA), and 58 healthy volunteers. The oral microbiota was assessed using 16S rRNA sequencing. We characterized oral microbiome, identified microbial markers, constructed and validated colorectal tumor (CRA and CRC) classifier.

Results: Oral microbial composition and diversity were significantly different among the three groups, and the CRA group had the highest diversity. Analysis of the functional potential of oral microbiota demonstrated that the pathway involving cell motility was overrepresented in the CRA and CRC groups relative to that in the healthy controls. Moreover, a random forest model was constructed based on oral microbial markers, which could distinguish the colorectal tumor groups from the healthy controls and achieve a powerful classification potential in the discovery and validation cohorts.

Conclusion: This study suggests a potential association between oral microbiome dysbiosis and colorectal cancer. Oral microbiota-based biomarkers may be helpful in predicting the risks for the development of CRA and CRC.

Germline pathogenic variant spectrum in 25 cancer susceptibility genes in Turkish breast and colorectal cancer patients and elderly controls

Inherited pathogenic variants account for 5% to 10% of all breast cancer (BC) and colorectal cancer (CRC) cases. Here, we sought to profile the pathogenic variants in 25 cancer susceptibility genes in Turkish population. Germline pathogenic variants were screened in 732 BC patients, 189 CRC patients and 490 cancer-free elderly controls, using next-generation sequencing-based multigene panel testing and multiplex ligation-dependent probe amplification testing. Pathogenic variants were detected in 17.2% of high-risk BC patients and 26.4% of high-risk CRC patients. More than 95% of these variants were clinically actionable. BRCA1/2 and mismatch repair genes (MLH1, MSH2 and MSH6) accounted for two-thirds of all pathogenic variants detected in high-risk BC and CRC patients, respectively. Pathogenic variants in PALB2, CHEK2, ATM and TP53 were also prevalent in high-risk BC patients (4.5%). BRCA1 exons 17-18 deletion and CHEK2 c.592+3A>T were the most common variants predisposing to BC, and they are likely to be founder variants. Three frequent MUTYH pathogenic variants (c.884C>T, c.1437_1439delGGA and c.1187G>A) were responsible for all MUTYH biallelic cases (4.4% of high-risk CRC patients). The total pathogenic variant frequency was very low in controls (2.4%) and in low-risk BC (3.9%) and CRC (6.1%) patients. Our study depicts the pathogenic variant spectrum and prevalence in Turkish BC and CRC patients, guiding clinicians and health authorities for genetic testing applications and variant classification in Turkish population.

POLE and POLD1 germline exonuclease domain pathogenic variants, a rare event in colorectal cancer from the Middle East

Background

Colorectal cancer (CRC) is a major contributor to morbidity and mortality related to cancer. Only ~5% of all CRCs occur as a result of pathogenic variants in well‐defined CRC predisposing genes. The frequency and effect of exonuclease domain pathogenic variants of POLE and POLD1 genes in Middle Eastern CRCs is still unknown.

Methods

Targeted capture sequencing and Sanger sequencing technologies were employed to investigate the germline exonuclease domain pathogenic variants of POLE and POLD1 in Middle Eastern CRCs. Immunohistochemical analysis of POLE and POLD1 was performed to look for associations between protein expression and clinico‐pathological characteristics.

Results

Five damaging or possibly damaging variants (0.44%) were detected in 1,135 CRC cases, four in POLE gene (0.35%, 4/1,135) and one (0.1%, 1/1,135) in POLD1 gene. Furthermore, low POLE protein expression was identified in 38.9% (417/1071) cases and a significant association with lymph node involvement (p = .0184) and grade 3 tumors (p = .0139) was observed. Whereas, low POLD1 expression was observed in 51.9% (555/1069) of cases and was significantly associated with adenocarcinoma histology (p = .0164), larger tumor size (T3 and T4 tumors; p = .0012), and stage III tumors (p = .0341).

Conclusion

POLE and POLD1 exonuclease domain pathogenic variants frequency in CRC cases was very low and these exonuclease domain pathogenic variants might be rare causative events of CRC in the Middle East. POLE and POLD1 can be included in multi‐gene panels to screen CRC patients.

Correlation study between serum neuro-specific enolase and gastric and colorectal cancers

This study investigated the diagnostic value of preoperative serum neuro-specific enolase (NSE) in gastric cancer (GC) and colorectal cancer (CRC), and the diagnostic viability of combined serum NSE, carcinoembryonic antigen (CEA), cancer antigen (CA)19-9, and CA242.Patients with GC and CRC, and a healthy control group (n = 666 and 266, respectively) were compared with regard to NSE, CEA, CA19-9, and CA242 serum levels. NSE was analyzed for associations with clinicopathological parameters. To estimate the diagnostic potential of NSE, a receiver operating characteristic curve was constructed and the area under the curve (AUCs) was calculated for different patient subgroups.The median serum NSE level of the tumor group (20.925 ng/mL) was significantly higher than that of the control (15.190 ng/mL). Serum NSE was associated with pathological tumor-node-metastasis staging, lymph node metastasis, distant metastasis, vascular invasion, and nerve infiltration. The area under the receiver operating characteristic curve (AUC) for NSE in GC and CRC (0.769) was higher than for the other 3 markers (0.571-0.680). The AUC of the combined markers was higher than for any of the markers individually (0.778-0.810).The AUC for NSE alone suggests it may be an independent tumor marker, and useful for diagnosis of GC and CRC. However, the AUC for combined NSE, CEA, CA19-9, and CA242 was higher and thus potentially more diagnostic value.

Mutation Analysis of Colorectal and Gastric Carcinomas Originating from Adenomas: Insights into Genomic Evolution Associated with Malignant Progression

Small malignant tumor foci arising from benign lesions are rare but offer a unique opportunity to investigate the genomic evolution that occurs during malignant transformation. In this study, we analyzed 11 colorectal and 10 gastric adenoma–carcinoma pairs, each of which represented malignant tumors (carcinomas) embedded in benign lesions (adenomas) found in the same patient. Whole-exome sequencing revealed that mutation abundance was variable across different cases, but comparable between adenoma–carcinoma pairs. When mutations were classified as adenoma-specific, carcinoma-specific, or common, adenoma-specific mutations were more enriched with subclonal mutations than were carcinoma-specific mutations, indicative of a perturbation in mutational subclonal architecture (such as selective sweep) during malignant transformation. Among the recurrent mutations in colorectal cancers, APC and KRAS mutations were common between adenomas and carcinomas, indicative of their early occurrence during genomic evolution. TP53 mutations were often observed as adenoma-specific and therefore likely not associated with the emergence of malignant clones. Clonality-based enrichment analysis revealed that subclonal mutations of extracellular matrix genes in adenomas are more likely to be clonal in carcinomas, indicating potential roles for these genes in malignant transformation. Compared with colorectal cancers, gastric cancers showed more lesion-specific mutations than common mutations and higher levels of discordance in copy number profiles between matched adenomas and carcinomas, which may explain the elevated evolutionary dynamics and heterogeneity of gastric cancers compared to colorectal cancers. Taken together, this study demonstrates that co-existing benign and malignant lesions enable the evolution-based categorization of genomic alterations that may reveal clinically important biomarkers in colorectal and gastric cancers.

Active Lifestyle Patterns Reduce the Risk of Colorectal Cancer in the North of Vietnam: A Hospital-Based Case-Control Study

A hospital-based, case-control study was conducted to investigate the association between lifestyle patterns and risk of colorectal cancer (CRC) in the north of Vietnam. Demographic factors employed for the models were age, sex, marital status, occupation, education, income, smoking status, alcohol consumption, vegetable consumption, tea, coffee consumption, and physical activity (PA). Individuals of both groups (n = 154 for the control group and n = 136 for the CRC group) were interviewed using a questionnaire by trained interviewers. The findings showed that moderate PA was inversely associated with CRC risk: odds ratio (OR) = 0.19, 95% confidence interval (CI) = 0.10 to 0.36 with P < .01. The total PA showed that the highest tertile (>2.7 MET-h/d) was associated with the reduced risk of CRC compared with the lowest tertile one after controlling for confounding factors: adjusted OR = 0.25, 95% CI = 0.09 to 0.74, P < .01. Sedentary time was associated with an increased level of CRC risk by 57% as compared between the highest tertile and the lowest one after controlling for confounding factors. Daily consumption of vegetables and 1 to 3 cups of tea per day or more were also associated with decreased risk of CRC. Despite promising findings, a limitation of this research is that it did not establish a temporal relationship between risk factors and CRC due to its retrospective design. However, this is the first analytic study highlighting the role of the active lifestyle pattern associated with reduced CRC risk in Vietnamese adults.

The critical role of calcineurin/NFAT (C/N) pathways and effective antitumor prospect for colorectal cancers

Transcription factors (TFs) like a nuclear factor of activated T-cells (NFAT) and its controller calcineurin are highly expressed in primary intestinal epithelial cells (IECs) due to delamination, damage by tumor-associated flora and selective activation in the intestinal tract tumor are crucial in the progression and growth of colorectal cancer (CRC). This study sought to summarize the current findings concerning the dysregulated calcineurin/NFAT (C/N) signaling involved in CRC initiation and progression. These signalings include proliferation, T-cell functions, and glycolysis with high lactate production that remodels the acidosis, which genes in tumor cells provide an evolutionary advantage, or even increased their attack phenotype. Moreover, the relationship between C/N and gut microbiome in CRC, especially role of NFAT and toll-like receptor signaling in regulating intestinal microbiota are also discussed. Furthermore, this review will discuss the proteins and genes relating to C/N induced acidosis in CRC, which includes ASIC2 regulated C/N1 and TFs associated with the glycolytic by-product that affect T-cell functions and CRC cell growth. It is revealed that calcineurin or NFAT targeting to antitumor, selective calcineurin inhibition or targets in NFAT signaling may be useful for clinical treatment of CRC. This can further aid in the identification of specific targets via cancer patient-personalized approach. Future studies should be focused on targeting to C/N or TLR signaling by the combination of therapeutic agents to regulate T-cell functions and gut microbiome for activating potent anticancer property with the prospect of potentiating the antitumor therapy for CRC.

Role of SCFAs in gut microbiome and glycolysis for colorectal cancer therapy

Increased risk of colorectal cancer (CRC) is associated with altered intestinal microbiota as well as short-chain fatty acids (SCFAs) reduction of output The energy source of colon cells relies mainly on three SCFAs, namely butyrate (BT), propionate, and acetate, while CRC transformed cells rely mainly on aerobic glycolysis to provide energy. This review summarizes recent research results for dysregulated glucose metabolism of SCFAs, which could be initiated by gut microbiome of CRC. Moreover, the relationship between SCFA transporters and glycolysis, which may correlate with the initiation and progression of CRC, are also discussed. Additionally, this review explores the linkage of BT to transport of SCFAs expressions between normal and cancerous colonocyte cell growth for tumorigenesis inhibition in CRC. Furthermore, the link between gut microbiota and SCFAs in the metabolism of CRC, in addition, the proteins and genes related to SCFAs-mediated signaling pathways, coupled with their correlation with the initiation and progression of CRC are also discussed. Therefore, targeting the SCFA transporters to regulate lactate generation and export of BT, as well as applying SCFAs or gut microbiota and natural compounds for chemoprevention may be clinically useful for CRCs treatment. Future research should focus on the combination these therapeutic agents with metabolic inhibitors to effectively target the tumor SCFAs and regulate the bacterial ecology for activation of potent anticancer effect, which may provide more effective application prospect for CRC therapy.

miR-148a inhibits early relapsed colorectal cancers and the secretion of VEGF by indirectly targeting HIF-1α under non-hypoxia/hypoxia conditions

Vascular endothelial growth factor (VEGF) is correlated with angiogenesis and early relapse of colorectal cancer (CRC). This study investigated the role of miR‐148a in the regulation of VEGF/angiogenesis and early relapse of CRC. We established a stable clone with miR‐148a expression in HCT116 and HT29 cell lines and created a hypoxic condition by using CoCl₂ to determine the underlying mechanism of miR‐148a. The effects of miR‐148a on the phosphoryl‐ERK (pERK)/hypoxia‐inducible factor‐1α (HIF‐1α)/VEGF pathway were evaluated through Western blotting and the inhibitory effect of miR‐148a on angiogenesis was demonstrated through a tube formation assay. Sixty‐three CRC tissues (28 early relapse and 35 non‐early relapse) were analysed to assess the relationship between miR‐148a and HIF‐1α/VEGF. The protein expression of pERK/HIF‐1α/VEGF in HCT116 and HT29 cells was significantly decreased by miR‐148a (all P < 0.05). The protein expression of VEGF/HIF‐1α was strongly inversely associated with the expression of miR‐148a in the 63 CRC tissue samples (all P < 0.05). Tube formation assay demonstrated that miR‐148a significantly obliterated angiogenesis. miR‐148a suppresses VEGF through down‐regulation of the pERK/HIF‐1α/VEGF pathway and might lead to the inhibition of angiogenesis; miR‐148a down‐regulation increased the early relapse rate of CRC. This demonstrates that miR‐148a is a potential diagnostic and therapeutic target.

Microbiota dysbiosis and barrier dysfunction in inflammatory bowel disease and colorectal cancers: exploring a common ground hypothesis

Inflammatory bowel disease (IBD) is a multifactorial disease which arises as a result of the interaction of genetic, environmental, barrier and microbial factors leading to chronic inflammation in the intestine. Patients with IBD had a higher risk of developing colorectal carcinoma (CRC), of which the subset was classified as colitis-associated cancers. Genetic polymorphism of innate immune receptors had long been considered a major risk factor for IBD, and the mutations were also recently observed in CRC. Altered microbial composition (termed microbiota dybiosis) and dysfunctional gut barrier manifested by epithelial hyperpermeability and high amount of mucosa-associated bacteria were observed in IBD and CRC patients. The findings suggested that aberrant immune responses to penetrating commensal microbes may play key roles in fueling disease progression. Accumulative evidence demonstrated that mucosa-associated bacteria harbored colitogenic and protumoral properties in experimental models, supporting an active role of bacteria as pathobionts (commensal-derived opportunistic pathogens). Nevertheless, the host factors involved in bacterial dysbiosis and conversion mechanisms from lumen-dwelling commensals to mucosal pathobionts remain unclear. Based on the observation of gut leakiness in patients and the evidence of epithelial hyperpermeability prior to the onset of mucosal histopathology in colitic animals, it was postulated that the epithelial barrier dysfunction associated with mucosal enrichment of specific bacterial strains may predispose the shift to disease-associated microbiota. The speculation of leaky gut as an initiating factor for microbiota dysbiosis that eventually led to pathological consequences was proposed as the "common ground hypothesis", which will be highlighted in this review. Overall, the understanding of the core interplay between gut microbiota and epithelial barriers at early subclinical phases will shed light to novel therapeutic strategies to manage chronic inflammatory disorders and colitis-associated cancers.

Lycorine Displays Potent Antitumor Efficacy in Colon Carcinoma by Targeting STAT3

Signal transducer and activator of transcription 3 (STAT3) is an attractive therapeutic target for cancer treatment. In this study, we identify lycorine is an effective inhibitor of STAT3, leading to repression of multiple oncogenic processes in colon carcinoma. Lycorine selectively inactivates phospho-STAT3 (Tyr-705), and subsequent molecular docking uncovers that lycorine directly binds to the SH2 domain of STAT3. Consequently, we find that lycorine exhibits anti-proliferative activity and induces cell apoptosis on human colorectal cancer (CRC) in vitro. Lycorine induces the activation of the caspase-dependent mitochondrial apoptotic pathway, as indicated by activation of caspase and increase of the ratio of Bax/Bcl-2 and mitochondrial depolarization. Overexpressing STAT3 greatly blocks these effects by lycorine in CRC cells. Finally, lycorine exhibits a potential therapeutic effect in xenograft colorectal tumors by targeting STAT3 without observed toxicity. Taken together, the present study indicates that lycorine acts as a promising inhibitor of STAT3, which blocks tumorigenesis in colon carcinoma.

New strategies for targeting glucose metabolism-mediated acidosis for colorectal cancer therapy

Colorectal cancer (CRC) is a heterogeneous group of diseases that are the result of abnormal glucose metabolism alterations with high lactate production by pyruvate to lactate conversion, which remodels acidosis and offers an evolutional advantage for tumor cells, even enhancing their aggressive phenotype. This review summarizes recent findings that involve multiple genes, molecules, and downstream signaling in the dysregulated glycolytic pathway, which can allow a tumor to initiate acid byproducts and to progress, thereby resulting in acidosis commonly found in the tumor microenvironment of CRC. Moreover, the relationship between CRC cells and the tumor acidic microenvironment, especially for regulating lactate production and lactate dehydrogenase A levels, is also discussed, as well as comprehensively defining different aspects of glycolytic pathways that affect cancer cell proliferation, invasion, and migration. Furthermore, this review concentrates on glucose metabolism-mediated transduction factors in CRC, which include acid-sensing ion channels, triosephosphate isomerase and key glycolysis-related enzymes that regulate glycolytic metabolites, coupled with the effect on tumor cell glycolysis as well as signaling pathways. In conclusion, glucose metabolism mediated by glycolytic pathways that are integral to tumor acidosis in CRC is demonstrated. Therefore, selective metabolic inhibitors or agents against these targets in glucose metabolism through glycolytic pathways may be clinically useful to regulate the tumor's acidic microenvironment for CRC treatment and to identify specific targets that regulate tumor acidosis through a cancer patient-personalized approach. Furthermore, strategies for modifying the metabolic processes that effectively inhibit cancer cell growth and tumor progression and activate potent anticancer effects may provide more effective antitumor prospects for CRC therapy.

Extensive screening of microRNA populations identifies hsa-miR-375 and hsa-miR-133a-3p as selective markers for human rectal and colon cancer

MicroRNAs (miRNAs) are ∼22-nt molecules exerting control of protein expression in cancer tissues. The current study determined the full spectrum of miRNA dysregulation in freshly isolated human colon or rectal cancer biopsies as well as in controls of healthy adjacent tissue (total of n = 100) using an Illumina sequencing technology. In this work, we aimed to identify miRNAs that may serve as future marker to discern between these two subtypes. DESeq2 analysis revealed 53 significantly dysregulated miRNAs in colon cancer, 67 miRNAs in rectal cancer, and 97 miRNAs in both at a P_adj value < 0.05 and ≥ 10 read counts. 65% of miRNAs were upregulated in colon as well as rectal cancer. Highest significant dysregulation (P_adj < 0.00001) was detected for hsa-miR-21-5p, -215-5p and -378a in both colon and rectal cancer. Among the group of miRNAs with P_adj < 0.05 and more than 2-fold expression differences, hsa-miR-375 was detected in rectal cancer only, and hsa-miR-133a-3p only in colon cancer. Receiver operating characteristic (ROC) analysis confirmed highly distinct sensitivities for hsa-miR-375 to detect rectal cancer (area under the curve (AUC): 0.9), while hsa-miR-133a-3p (AUC: 0.89) had the highest sensitivity for detecting colon cancer. We conclude that hsa-miR-375 and hsa-miR-133a-3p may serve as new markers of rectal or colon cancer and should be further investigated to search for different etiologies of colorectal cancer.

Tetrac downregulates β-catenin and HMGA2 to promote the effect of resveratrol in colon cancer

The molecular pathogenesis of colorectal cancer encompasses the activation of several oncogenic signaling pathways that include the Wnt/β-catenin pathway and the overexpression of high mobility group protein A2 (HMGA2). Resveratrol - the polyphenolic phytoalexin - binds to integrin αvβ3 to induce apoptosis in cancer cells via cyclooxygenase 2 (COX-2) nuclear accumulation and p53-dependent apoptosis. Tetraiodothyroacetic acid (tetrac) is a de-aminated derivative of l-thyroxine (T₄), which - in contrast to the parental hormone - impairs cancer cell proliferation. In the current study, we found that tetrac promoted resveratrol-induced anti-proliferation in colon cancer cell lines, in primary cultures of colon cancer cells, and in vivo The mechanisms implicated in this action involved the downregulation of nuclear β-catenin and HMGA2, which are capable of compromising resveratrol-induced COX-2 nuclear translocation. Silencing of either β-catenin or HMGA2 promoted resveratrol-induced anti-proliferation and COX-2 nuclear accumulation which is essential for integrin αvβ3-mediated-resveratrol-induced apoptosis in cancer cells. Concurrently, tetrac enhanced nuclear abundance of chibby family member 1, the nuclear β-catenin antagonist, which may further compromise the nuclear β-catenin-dependent gene expression and proliferation. Taken together, these results suggest that tetrac targets β-catenin and HMGA2 to promote resveratrol-induced-anti-proliferation in colon cancers, highlighting its potential in anti-cancer combination therapy.

Exome and transcriptome sequencing identifies loss of PDLIM2 in metastatic colorectal cancers

Background

Understanding the genomic determinants associated with metastasis in colorectal cancers (CRCs) provides crucial clues for improving patient care.

Patients and methods

In this study, we performed whole-exome sequencing as well as RNA sequencing analyses on five pairs of primary and liver metastasized samples from CRC patients together with blood/normal control samples for each pair.

Results

We identified genomic deletions in the region of 8p21-23 (q value <0.01) from analysis of recurrent regions with copy number variations in both primary and matched metastatic lesions. Consistent with this result, we found significantly decreased expression levels of all 12 genes (ADAMDEC1, C8orf80, CLDN23, EPHX2, GFRA2, NEFL, NEFM, PDLIM2, PTK2B, SCARA5, SLC18A1 and STMN4) located within this region (adjusted P<0.01). Notably, the mRNA levels of PDLIM2, a key regulator of well-known cancer-associated genes including the proto-oncogene c-MYC, an early response gene IER3, and regulators of apoptosis such as BCL2, FAS, and FASLG, were highly downregulated in tumors compared to normal tissues.

Conclusion

Taken together, our findings uncovered various genomic alterations potentially leading to metastasis in CRC and provide important insights into the development of potential therapeutic targets for preventing metastatic progression of CRC.

Colorectal Cancer Incidence Trend and Projections in Tunisia (1994 - 2024)

Objectives: The aim of this study was to describe trends of colorectal cancer incidence during the period 1994-2009 and to generate projections until 2024. Methods: The North-Tunisia Cancer Registry (NTCR) was the source of data for patients with CRC. This registry lists, since 1994, cases of malignant tumors in people living in North Tunisia, including the District of Tunis, the north east and the north west. Cases were classified using the International Classification of Diseases for Oncology. Data were analyzed using R software and Joinpoint one was employed to analyse trends. Projections were performed using the Age Period Cohort based on poisson regression. Results: During the period 1994 to 2009, 6,909 new cases of CRC were registered in Northern Tunisia. The age standardized incidence rate (ASR) increased significantly from 6.4/100,000 in 1994 to 12.4/100,000 in 2009. Trends in CRC incidence was significantly rising with an annual percentage change (APC) of + 3,9% [2.8% -5.1%]. Without effective interventions, the predicted CRC ASR would be 39.3/100,000 [CI 95%: 32,9/100,000 - 48,8/100,000] in 2024. Conclusion: The incidence of colorectal cancer is clearly increasing in Tunisia. Strengthening of screening and primary prevention measures is to be recommended.

Investigation of clinicopathological parameters in emergency colorectal cancer surgery: a study of 67 patients

INTRODUCTION

The aim of the present study was to establish, having adjusted for case mix, the size of the differences in postoperative mortality and 5-year survival between patients presenting as an emergency with evidence of obstruction and perforation and the association of clinicopathological factors with mortality (bivariate analyses).

MATERIAL AND METHODS

The study included 67 patients who presented with colorectal cancer (CRC) between 2009 and 2013 in Iran. The mean age of the patients was 59.7 years. Of the 67 patients, 37 (55.22%) were male and 30 (44.77%) were female. Certain parameters that correlated with CRC and surgical treatment were investigated.

RESULTS

Our results showed that 46 (68.65%) patients had obstruction, while perforation was observed in 21 (31.34%) cases. Among the patients with obstruction, obstruction of the right colon was observed in 29 (43.28%) cases. There was no significant difference in mortality rate between right and left colonic obstruction. Based on the bivariate analyses, our findings showed that death of patients was significantly related to tumor grade (p = 0.02) and TNM staging (p = 0.026), but no association was found between other parameters and death, including age, sex, and tumor site.

CONCLUSIONS

Compared with patients who undergo elective surgery for colon cancer, those who present as an emergency with evidence of obstruction or perforation have higher postoperative mortality rates and poorer cancer-specific survival. Also, colorectal cancer patients with emergency surgery showed aggressive histopathology and an advanced stage.

Epstein-Barr virus and its association with Fascin expression in colorectal cancers in the Syrian population: A tissue microarray study

Colorectal cancer (CRC) is the third most common malignancy in both men and women worldwide. Colorectal carcinogenesis is a complex, multistep process involving environmental and lifestyle features as well as sequential genetic changes in addition to bacterial and viral infections. Viral infection has a proven role in the incidence of approximately 20% of human cancers including gastric malignancies. Accordingly, Epstein-Barr virus (EBV) has been recently shown to be present in human gastric cancers, which could play an important role in the initiation and progression of these cancers. Therefore, this work explores the prevalence of EBV in 102 CRC tissues from the Syrian population using polymerase chain reaction (PCR) and tissue microarray (TMA) analysis. We found that EBV is present in 37 (36.27%) of CRC samples. Additionally, the expression of LMP1 onco-protein of EBV was found to be correlated with Fascin expression/overexpression in the majority of CRC tissue samples, which are intermediate/high grade invasive carcinomas. Our data indicate that EBV is present in CRC and its presence is associated with more aggressive cancer phenotype. Consequently, future investigations are needed to expose the role of EBV in CRC initiation and progression.

The pathological behaviors and prognostic factors of Chinese and Japanese colorectal cancers from general hospitals: a comparative study of the inpatients with surgical operation

Here, we collected the information of 17304 and 2014 inpatients with colorectal cancer (CRC) from general hospitals of China and Japan respectively, and analyzed microscopic and macroscopic aspects, even stratified by the age and gender. It was found that Chinese CRC patients showed younger prone, more rectal and ascending cancers, less sigmoid and transverse cancers, larger size, less invasion into lymphatic system or metastasis into lymph node, and poorer differentiation than Japanese ones (p < 0.05). TNM staging was employed as an independent factor for the prognosis of the CRC patients regardless of the country (p < 0.05). Female patients showed larger tumor size, easier invasion and metastasis into lymphatic system, and worse differentiation than males (p < 0.05). The younger patients displayed frequent invasion and metastasis into lymphatic system, and poor differentiation in comparison to elder ones (p < 0.05). These findings demonstrated that Japanese patients seemed to have more invasion and metastasis due to standard and precise operation and pathological diagnosis accuracy. Actually, Chinese patients had more aggressive pathological characteristics and a poorer prognosis. Therefore, it is essential to establish a routine screening methodology, a standard treatment system and postoperative diagnosis protocol for the prevention and therapeutics of Chinese CRC patients, especially for female and young patients.

Yield of adenomas and colorectal cancers within 5 years of a negative colonoscopy: are the guidelines guiding?

BACKGROUND

Screening for colorectal cancers outside the recommended guidelines presents a considerable burden to resource management in many public hospitals. The aim of this study is to evaluate the frequency, indications and outcomes for repeat colonoscopy performed within 5 years of a negative colonoscopy.

METHODS

A retrospective review of all colonoscopies at Nambour Hospital in 2008 was performed to identify those with a negative colonoscopy. The charts of patients undergoing repeat colonoscopy at the same institution within 5 years of a negative colonoscopy were examined further, and data obtained regarding indications and outcomes of subsequent colonoscopies.

RESULTS

A total of 616 colonoscopies were identified, 427 (69.3%) were negative for adenoma and carcinoma. Of these patients, 74 (17.3%) underwent a repeat colonoscopy at Nambour Hospital within 5 years. Eighteen out of 74 (24.3%) were outside guideline recommendation. Overall, one patient (1.4%) had cancer and 11 patients (14.9%) had polyps detected at repeat colonoscopy. Most of the polyps detected had low-risk features and were detected in the fourth and fifth years of the study period.

CONCLUSION

The yield of a second colonoscopy within 5 years of a good-quality negative colonoscopy is low but not zero. In the absence of new concerning symptoms or other risk factors, patients can be reassured and guidelines adhered to.

Epigenetic silencing of NDRG2 promotes colorectal cancer proliferation and invasion

BACKGROUND

Genome-wide methylation arrays have revealed aberrant methylation of N-Myc downstream-regulated gene 2 (NDRG2) promoter in colorectal cancer (CRC). This study investigated the role of NDRG2 in colorectal carcinogenesis.

METHODS

The aberrant promoter methylation, mRNA, and protein expression of NDRG2 were evaluated in 27 pairs of human CRC and adjacent normal tissues and seven human CRC-derived cell-lines. After stable NDRG2 over-expressed RKO and DLD-1 human CRC cell-lines were constructed, in vitro functional assays, including colony formation, cell viability, proliferation, invasion and migration assays, and in vivo xenograft models were performed.

RESULTS

The promoter of NDRG2 was methylated in 89% human CRC tissue compared to adjacent normal colonic mucosa (7.4%; P < 0.001). High-level methylation of NDRG2 promoter was more prevalent in proximal CRC (P = 0.022) and advanced T stage (P = 0.039). NDRG2 mRNA and protein expression was down-regulated in 89% and 100% human CRC tissue, respectively. In human CRC cell-lines, the promoter of NDRG2 was methylated aberrantly and mRNA, and protein expression of NDRG2 was down-regulated. NDRG2 mRNA expression was reactivated by 5-aza-2'-deoxycytidine. Colony formation of NDRG2 over-expressing RKO cells was inhibited (P = 0.012), as was the viability, proliferation, and invasion of NDRG2 over-expressing DLD-1 cells (P < 0.001, P = 0.003, and P = 0.044, respectively). Tumor volume in xenograft mice transplanted with NDRG2 over-expressing RKO and DLD-1 cells was smaller than that in controls (P = 0.002 and P = 0.001, respectively).

CONCLUSIONS

Epigenetic silencing of NDRG2 induces proliferation and invasion of CRC and may be associated with proximal CRC and advanced T stage. NDRG2 methylation might serve as novel biomarker of CRC.

Cathepsin B promotes colorectal tumorigenesis, cell invasion, and metastasis

Cathepsin B is a cysteine proteinase that primarily functions as an endopeptidase within endolysosomal compartments in normal cells. However, during tumoral expansion, the regulation of cathepsin B can be altered at multiple levels, thereby resulting in its overexpression and export outside of the cell. This may suggest a possible role of cathepsin B in alterations leading to cancer progression. The aim of this study was to determine the contribution of intracellular and extracellular cathepsin B in growth, tumorigenesis, and invasion of colorectal cancer (CRC) cells. Results show that mRNA and activated levels of cathepsin B were both increased in human adenomas and in CRCs of all stages. Treatment of CRC cells with the highly selective and non‐permeant cathepsin B inhibitor Ca074 revealed that extracellular cathepsin B actively contributed to the invasiveness of human CRC cells while not essential for their growth in soft agar. Cathepsin B silencing by RNAi in human CRC cells inhibited their growth in soft agar, as well as their invasion capacity, tumoral expansion, and metastatic spread in immunodeficient mice. Higher levels of the cell cycle inhibitor p27^Kip1 were observed in cathepsin B‐deficient tumors as well as an increase in cyclin B1. Finally, cathepsin B colocalized with p27^Kip1 within the lysosomes and efficiently degraded the inhibitor. In conclusion, the present data demonstrate that cathepsin B is a significant factor in colorectal tumor development, invasion, and metastatic spreading and may, therefore, represent a potential pharmacological target for colorectal tumor therapy. © 2015 The Authors. Molecular Carcinogenesis, published by Wiley Periodicals, Inc.

Intestinal tumor in a dish

Predicting the response of colorectal cancer (CRC) tumors to novel chemotherapeutic agents is significantly complicated by their underlying genetic and epigenetic diversity. Large-scale clinical trials involving thousands of patients are often necessary in order to accurately determine efficacy during drug development. Recent advances in genetic sequencing has allowed us to improve the prediction of drug response through genetic stratification of patients into smaller populations, yet the complexity of the cancer genome still often confounds accuracy of drug response prediction. Ultimately, we may need to replicate patient's own tumor in a dish in order to test drug responses so that the optimal treatment can be identified. We recently developed highly efficient and tractable organoid culture system for intestinal stem cells, in which single stem cells form 3D structures recapitulating original tissue architecture. This technology has also been applied to colorectal tumors and enables us to monitor the growth and response of the patient's own tumors. In this review, we provide an overview focusing on CRC organoid culture and its perspective for clinical applications.

Correlation of pretreatment hemoglobin and platelet counts with clinicopathological features in colorectal cancer in Saudi population

BACKGROUND/AIMS

In Saudi Arabia, colorectal cancers (CRCs) are registered as the second most common cancers. However, no data has been reported about correlation of the severity of the anemia and pretreatment platelets level with clinicopathological features of CRCs. We aimed to evaluate the association between pretreatment hemoglobin and platelets level and the clinicopathological features of CRC patients in Saudi Arabia.

MATERIALS AND METHODS

Between September 2005 and November 2011, One hundred and fifty-four confirmed CRC patients underwent thorough physical examination, blood investigations, endoscopic ultrasonography (EUS), and computed tomography (CT) for staging before surgery. Findings of physical assessment, EUS, CT, and pathological specimens were correlated with pretreatment hemoglobin and platelets levels the Pearson-Kendall tau correlative coefficients.

RESULTS

The mean age of cohort was 56.6 years (range: 26-89). Left-sided CRC were predominant (97 patients; 63%). Mean size of primary tumor was 6 cms (1-18) SD ± 3.55. Mean values of hemoglobin, red blood cells, hematocrit, white blood cells, and platelets were 11.9 SD ± 2.3, 35.5 SD ± 5.7, 4.43 × 10 6 /mL SD ± 0.6, 7.67 10 6 /mL SD ± 2.44, and 343 × 10 3 /mL SD ± 164.4, respectively. Pretreatment hemoglobin was inversely correlated with primary tumor size (R: 0.71, R2: 1.55, P = 0.0001) and nodal status (R: 0.02, R2: 0.05, P = 0.01). Right-sided CRC had significantly low pretreatment hemoglobin levels ( P = 0.001). Interestingly, pretreatment thrombocytosis was seen only in right-sided CRC (P = 0.0001).

CONCLUSION

Pretreatment anemia and thrombocytosis were found mainly in right-sided CRCs and advanced primary and nodal stages. Pretreatment hemoglobin and thrombocytosis can be considered as useful prognostic markers in CRC patients.

Adrenomedullin is a therapeutic target in colorectal cancer

The KRAS oncogene influences angiogenesis, metastasis and chemoresistance in colorectal cancers (CRCs), and these processes are all enhanced in hypoxic conditions. To define functional activities of mutant KRAS in a hypoxic microenvironment, we first performed cDNA microarray experiments in isogenic DKs5 and DKO3 colon cancer cell lines that differ only by their expression of mutant KRAS (K-ras(D13)). Adrenomedullin (ADM) was identified as one of the most significantly upregulated genes in DKs5 cells that express the KRAS oncogene in hypoxia (3.2-fold, p = 1.47 × 10(-5)). Ectopic expression of mutant KRAS (K-ras(V12)) in Caco-2 cells (K-ras(WT)) induced ADM, whereas selective knockdown of mutant KRAS alleles (K-ras(D13) or K-ras(V12)) in HCT116, DLD1 and SW480 colon cancer cells suppressed the expression of ADM in hypoxia. Knockdown of ADM in colon tumor xenografts blocked angiogenesis and stimulated apoptosis, resulting in tumor suppression. Furthermore, ADM also regulated colon cancer cell invasion in vitro. Among 56 patients with CRC, significantly higher expression levels of ADM were observed in samples harboring a KRAS mutation. Collectively, ADM is a new target of oncogenic KRAS in the setting of hypoxia. This observation suggests that therapeutic targets may differ depending upon the specific tumor microenvironment.