Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Body mass index and survival among patients with advanced biliary tract cancer: a single-institutional study with nationwide data-based validation

BACKGROUND

Excess body weight may modulate the progression of various cancer types. The prognostic relevance of body mass index (BMI) has not been fully examined in patients with biliary tract cancer.

METHODS

Using a single-institutional cohort of 360 patients receiving gemcitabine-based chemotherapy for advanced biliary tract cancer, we examined the association of BMI with overall survival (OS). Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for OS according to BMI. The findings were validated using a Japanese nationwide inpatient database including 8324 patients treated at 201 hospitals.

RESULTS

In the clinical cohort, BMI was not associated with OS (Ptrend = 0.34). Compared to patients with BMI = 18.5-24.9 kg/m2, patients with BMI < 18.5 kg/m2 and ≥ 25.0 kg/m2 had adjusted HRs for OS of 1.06 (95% CI, 0.78-1.45) and 1.01 (95% CI, 0.74-1.39), respectively. There was no evidence on a non-linear relationship between BMI and OS (Pnonlinearity = 0.63). In the nationwide cohort, the null findings were validated (Ptrend = 0.18) with adjusted HRs of 1.07 (95% CI, 0.98-1.18) for BMI < 18.5 kg/m2 and 1.05 (95% CI, 0.96-1.14) for BMI ≥ 25.0 kg/m2 (vs. BMI = 18.5-24.9 kg/m2). In the clinical cohort, BMI was not associated with progression-free survival (Ptrend = 0.81).

CONCLUSIONS

BMI was not associated with survival outcomes of patients with advanced biliary tract cancer. Further research is warranted incorporating more detailed body composition metrics to explore the prognostic role of adiposity in biliary tract cancer.

Analytical challenges in omics research on asthma and allergy: A National Institute of Allergy and Infectious Diseases workshop

Studies of asthma and allergy are generating increasing volumes of omics data for analysis and interpretation. The National Institute of Allergy and Infectious Diseases (NIAID) assembled a workshop comprising investigators studying asthma and allergic diseases using omics approaches, omics investigators from outside the field, and NIAID medical and scientific officers to discuss the following areas in asthma and allergy research: genomics, epigenomics, transcriptomics, microbiomics, metabolomics, proteomics, lipidomics, integrative omics, systems biology, and causal inference. Current states of the art, present challenges, novel and emerging strategies, and priorities for progress were presented and discussed for each area. This workshop report summarizes the major points and conclusions from this NIAID workshop. As a group, the investigators underscored the imperatives for rigorous analytic frameworks, integration of different omics data types, cross-disciplinary interaction, strategies for overcoming current limitations, and the overarching goal to improve scientific understanding and care of asthma and allergic diseases.

Cultivable Microbiome Approach Applied to Cervical Cancer Exploration

Traditional microbiological methodology is valuable and essential for microbiota composition description and microbe role assignations at different anatomical sites, including cervical and vaginal tissues; that, combined with molecular biology strategies and modern identification approaches, could give a better perspective of the microbiome under different circumstances. This pilot work aimed to describe the differences in microbiota composition in non-cancer women and women with cervical cancer through a culturomics approach combining culture techniques with Vitek mass spectrometry and 16S rDNA sequencing. To determine the possible differences, diverse statistical, diversity, and multivariate analyses were applied; the results indicated a different microbiota composition between non-cancer women and cervical cancer patients. The Firmicutes phylum dominated the non-cancer (NC) group, whereas the cervical cancer (CC) group was characterized by the predominance of Firmicutes and Proteobacteria phyla; there was a depletion of lactic acid bacteria, an increase in the diversity of anaerobes, and opportunistic and non-typical human microbiota isolates were present. In this context, we hypothesize and propose a model in which microbial composition and dynamics may be essential for maintaining the balance in the cervical microenvironment or can be pro-oncogenesis microenvironmental mediators in a process called Ying-Yang or have a protagonist/antagonist microbiota role.

Insights into the Microbial Composition of Intratumoral, Reproductive Tract, and Gut Microbiota in Ovarian Cancer Patients

According to the latest global cancer data, ovarian cancer is the deadliest among all gynecological malignant tumors and ranks fifth in terms of mortality. Its etiology and pathogenesis are unknown, and the 5-year survival rate of patients with advanced ovarian cancer is only 40% (Sung et al. CA Cancer J Clin 71:209-49, 2021). Recent research has shown that the human microbiota plays a crucial role in the development and progression of tumors, including ovarian cancer. Numerous studies have highlighted the complex connections between the reproductive tract microbiota, intestinal microbiota, and ovarian cancer (Jacobson et al. PeerJ 9:e11574, 2021). Therefore, this chapter will delve into composition, function, and the correlation between microbiota and immunity in the field of ovarian cancer microbiota, as well as the potential of bacteria in therapeutics and diagnostics of ovarian cancer.

The microbiome and rise of early-onset cancers: knowledge gaps and research opportunities

Accumulating evidence indicates an alarming increase in the incidence of early-onset cancers, which are diagnosed among adults under 50 years of age, in the colorectum, esophagus, extrahepatic bile duct, gallbladder, liver, stomach, pancreas, as well as the bone marrow (multiple myeloma), breast, head and neck, kidney, prostate, thyroid, and uterine corpus (endometrium). While the early-onset cancer studies have encompassed research on the wide variety of organs, this article focuses on research on digestive system cancers. While a minority of early-onset cancers in the digestive system are associated with cancer-predisposing high penetrance germline genetic variants, the majority of those cancers are sporadic and multifactorial. Although potential etiological roles of diets, lifestyle, environment, and the microbiome from early life to adulthood (i.e. in one's life course) have been hypothesized, exact contribution of each of these factors remains uncertain. Diets, lifestyle patterns, and environmental exposures have been shown to alter the oral and intestinal microbiome. To address the rising trend of early-onset cancers, transdisciplinary research approaches including lifecourse epidemiology and molecular pathological epidemiology frameworks, nutritional and environmental sciences, multi-omics technologies, etc. are needed. We review current evidence and discuss emerging research opportunities, which can improve our understanding of their etiologies and help us design better strategies for prevention and treatment to reduce the cancer burden in populations.

Effects of Long Non-Coding RNAs Induced by the Gut Microbiome on Regulating the Development of Colorectal Cancer

Although an imbalanced gut microbiome is closely associated with colorectal cancer (CRC), how the gut microbiome affects CRC is not known. Long non-coding RNAs (lncRNAs) can affect important cellular functions such as cell division, proliferation, and apoptosis. The abnormal expression of lncRNAs can promote CRC cell growth, proliferation, and metastasis, mediating the effects of the gut microbiome on CRC. Generally, the gut microbiome regulates the lncRNAs expression, which subsequently impacts the host transcriptome to change the expression of downstream target molecules, ultimately resulting in the development and progression of CRC. We focused on the important role of the microbiome in CRC and their effects on CRC-related lncRNAs. We also reviewed the impact of the two main pathogenic bacteria, Fusobacterium nucleatum and enterotoxigenic Bacteroides fragilis, and metabolites of the gut microbiome, butyrate, and lipopolysaccharide, on lncRNAs. Finally, available therapies that target the gut microbiome and lncRNAs to prevent and treat CRC were proposed.

Is early-onset cancer an emerging global epidemic? Current evidence and future implications

Over the past several decades, the incidence of early-onset cancers, often defined as cancers diagnosed in adults <50 years of age, in the breast, colorectum, endometrium, oesophagus, extrahepatic bile duct, gallbladder, head and neck, kidney, liver, bone marrow, pancreas, prostate, stomach and thyroid has increased in multiple countries. Increased use of screening programmes has contributed to this phenomenon to a certain extent, although a genuine increase in the incidence of early-onset forms of several cancer types also seems to have emerged. Evidence suggests an aetiological role of risk factor exposures in early life and young adulthood. Since the mid-20th century, substantial multigenerational changes in the exposome have occurred (including changes in diet, lifestyle, obesity, environment and the microbiome, all of which might interact with genomic and/or genetic susceptibilities). However, the effects of individual exposures remain largely unknown. To study early-life exposures and their implications for multiple cancer types will require prospective cohort studies with dedicated biobanking and data collection technologies. Raising awareness among both the public and health-care professionals will also be critical. In this Review, we describe changes in the incidence of early-onset cancers globally and suggest measures that are likely to reduce the burden of cancers and other chronic non-communicable diseases.

Western-Style Diet, pks Island-Carrying Escherichia coli, and Colorectal Cancer: Analyses From Two Large Prospective Cohort Studies

BACKGROUND & AIMS

Evidence supports a carcinogenic role of Escherichia coli carrying the pks island that encodes enzymes for colibactin biosynthesis. We hypothesized that the association of the Western-style diet (rich in red and processed meat) with colorectal cancer incidence might be stronger for tumors containing higher amounts of pks+E coli.

METHODS

Western diet score was calculated using food frequency questionnaire data obtained every 4 years during follow-up of 134,775 participants in 2 United States-wide prospective cohort studies. Using quantitative polymerase chain reaction, we measured pks+E coli DNA in 1175 tumors among 3200 incident colorectal cancer cases that had occurred during the follow-up. We used the 3200 cases and inverse probability weighting (to adjust for selection bias due to tissue availability), integrated in multivariable-adjusted duplication-method Cox proportional hazards regression analyses.

RESULTS

The association of the Western diet score with colorectal cancer incidence was stronger for tumors containing higher levels of pks+E coli (Pheterogeneity = .014). Multivariable-adjusted hazard ratios (with 95% confidence interval) for the highest (vs lowest) tertile of the Western diet score were 3.45 (1.53-7.78) (Ptrend = 0.001) for pks+E coli-high tumors, 1.22 (0.57-2.63) for pks+E coli-low tumors, and 1.10 (0.85-1.42) for pks+E coli-negative tumors. The pks+E coli level was associated with lower disease stage but not with tumor location, microsatellite instability, or BRAF, KRAS, or PIK3CA mutations.

CONCLUSIONS

The Western-style diet is associated with a higher incidence of colorectal cancer containing abundant pks+E coli, supporting a potential link between diet, the intestinal microbiota, and colorectal carcinogenesis.

Cancer as microenvironmental, systemic and environmental diseases: opportunity for transdisciplinary microbiomics science

Cancer is generally regarded as a localised disease, with the well-established role of the tumour microenvironment. However, the realm of cancer goes beyond the tumour microenvironment, and cancer should also be regarded as a systemic and environmental disease. The exposome (ie, the totality of exposures), which encompasses diets, supplements, smoking, alcohol, other lifestyle factors, medications, etc, likely alters the microbiome (inclusive of bacteria, viruses, archaea, fungi, parasites, etc) and immune system in various body sites and influences tumour phenotypes. The systemic metabolic/inflammatory status, which is likely influenced by exposures and intestinal physiological changes, may affect tissue microenvironment of colorectum and any other organs. Germline genomic factors can modify disease phenotypes via gene-by-environment interactions. Although challenges exist, it is crucial to advance not only basic experimental research that can analyse the effects of exposures, microorganisms and microenvironmental components on tumour evolution but also interdisciplinary human population research that can dissect the complex pathogenic roles of the exposome, microbiome and immunome. Metagenomic, metatranscriptomic and metabolomic analyses should be integrated into well-designed population research combined with advanced methodologies of artificial intelligence and molecular pathological epidemiology. Ideally, a prospective cohort study design that enables biospecimen (such as stool) collection before disease detection should be considered to address reverse causation and recall biases. Robust experimental and observational research together can provide insights into dynamic interactions between environmental exposures, microbiota, tumour and immunity during carcinogenesis processes, thereby helping us develop precision prevention and therapeutic strategies to ultimately reduce the cancer burden.

Methods for Stratification and Validation Cohorts: A Scoping Review

Personalized medicine requires large cohorts for patient stratification and validation of patient clustering. However, standards and harmonized practices on the methods and tools to be used for the design and management of cohorts in personalized medicine remain to be defined. This study aims to describe the current state-of-the-art in this area. A scoping review was conducted searching in PubMed, EMBASE, Web of Science, Psycinfo and Cochrane Library for reviews about tools and methods related to cohorts used in personalized medicine. The search focused on cancer, stroke and Alzheimer’s disease and was limited to reports in English, French, German, Italian and Spanish published from 2005 to April 2020. The screening process was reported through a PRISMA flowchart. Fifty reviews were included, mostly including information about how data were generated (25/50) and about tools used for data management and analysis (24/50). No direct information was found about the quality of data and the requirements to monitor associated clinical data. A scarcity of information and standards was found in specific areas such as sample size calculation. With this information, comprehensive guidelines could be developed in the future to improve the reproducibility and robustness in the design and management of cohorts in personalized medicine studies.

Utility of Continuous Disease Subtyping Systems for Improved Evaluation of Etiologic Heterogeneity

Molecular pathologic diagnosis is important in clinical (oncology) practice. Integration of molecular pathology into epidemiological methods (i.e., molecular pathological epidemiology) allows for investigating the distinct etiology of disease subtypes based on biomarker analyses, thereby contributing to precision medicine and prevention. However, existing approaches for investigating etiological heterogeneity deal with categorical subtypes. We aimed to fully leverage continuous measures available in most biomarker readouts (gene/protein expression levels, signaling pathway activation, immune cell counts, microbiome/microbial abundance in tumor microenvironment, etc.). We present a cause-specific Cox proportional hazards regression model for evaluating how the exposure-disease subtype association changes across continuous subtyping biomarker levels. Utilizing two longitudinal observational prospective cohort studies, we investigated how the association of alcohol intake (a risk factor) with colorectal cancer incidence differed across the continuous values of tumor epigenetic DNA methylation at long interspersed nucleotide element-1 (LINE-1). The heterogeneous alcohol effect was modeled using different functions of the LINE-1 marker to demonstrate the method's flexibility. This real-world proof-of-principle computational application demonstrates how the new method enables visualizing the trend of the exposure effect over continuous marker levels. The utilization of continuous biomarker data without categorization for investigating etiological heterogeneity can advance our understanding of biological and pathogenic mechanisms.

Field cancerization in breast cancer

Breast cancer affects one in seven women worldwide during their lifetime. Widespread mammographic screening programs and education campaigns allow for early detection of the disease, often during its asymptomatic phase. Current practice in treatment and recurrence monitoring is based primarily on pathological evaluations but can also encompass genomic evaluations, both of which focus on the primary tumor. Although breast cancer is one of the most studied cancers, patients still recur at a rate of up to 15% within the first 10 years post‐surgery. Local recurrence was originally attributed to tumor cells contaminating histologically normal (HN) tissues beyond the surgical margin, but advances in technology have allowed for the identification of distinct aberrations that exist in the peri‐tumoral tissues themselves. One leading theory to explain this phenomenon is the field cancerization theory. Under this hypothesis, tumors arise from a field of molecularly altered cells that create a permissive environment for malignant evolution, which can occur with or without morphological changes. The traditional histopathology paradigm dictates that molecular alterations are reflected in the tissue phenotype. However, the spectrum of inter‐patient variability of normal breast tissue may obfuscate recognition of a cancerized field during routine diagnostics. In this review, we explore the concept of field cancerization focusing on HN peri‐tumoral tissues: we present the pathological and molecular features of field cancerization within these tissues and discuss how the use of peri‐tumoral tissues can affect research. Our observations suggest that pathological and molecular evaluations could be used synergistically to assess risk and guide the therapeutic management of patients. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Alterations in the Gut Microbiota and Their Metabolites in Colorectal Cancer: Recent Progress and Future Prospects

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality worldwide. The etiology and pathogenesis of CRC remain unclear. A growing body of evidence suggests dysbiosis of gut bacteria can contribute to the occurrence and development of CRC by generating harmful metabolites and changing host physiological processes. Metabolomics, a systems biology method, will systematically study the changes in metabolites in the physiological processes of the body, eventually playing a significant role in the detection of metabolic biomarkers and improving disease diagnosis and treatment. Metabolomics, in particular, has been highly beneficial in tracking microbially derived metabolites, which has substantially advanced our comprehension of host-microbiota metabolic interactions in CRC. This paper has briefly compiled recent research progress of the alterations of intestinal flora and its metabolites associated with CRC and the application of association analysis of metabolomics and gut microbiome in the diagnosis, prevention, and treatment of CRC; furthermore, we discuss the prospects for the problems and development direction of this association analysis in the study of CRC. Gut microbiota and their metabolites influence the progression and causation of CRC, and the association analysis of metabolomics and gut microbiome will provide novel strategies for the prevention, diagnosis, and therapy of CRC.

Patient-centered developments in colon- and rectal cancer with a multidisciplinary international team: From translational research to national guidelines

Rarely, scientific developments centered around the patient as a whole are published. Our multidisciplinary group, headed by gastrointestinal surgeons, applied this research philosophy considering the most important aspects of the diseases “colon- and rectal cancer” in the long-term developments. Good expert cooperation/knowledge at the Comprehensive Cancer Center Ulm (CCCU) were applied in several phase III trials for multimodal treatments of primary tumors (MMT) and metastatic diseases (involving nearly 2000 patients and 64 centers), for treatment individualization of MMT and of metastatic disease, for psycho-oncology/quality of life involving the patients’ wishes, and for disease prevention. Most of the targets initially were heavily rejected/discussed in the scientific communities, but now have become standards in treatments and national guidelines or are topics in modern translational research protocols involving molecular biology for e.g., “patient centered individualized treatment”. In this context we also describe the paths we had to tread in order to realize our new goals, which at the end were highly beneficial for the patients from many points of view. This description is also important for students and young researchers who, with an actual view on our recent developments, might want to know how medical progress was achieved.

Prostate Microbiota and Prostate Cancer: A New Trend in Treatment

Although the incidence and mortality of prostate cancer have gradually begun to decline in the past few years, it is still one of the leading causes of death from malignant tumors in the world. The occurrence and development of prostate cancer are affected by race, family history, microenvironment, and other factors. In recent decades, more and more studies have confirmed that prostate microflora in the tumor microenvironment may play an important role in the occurrence, development, and prognosis of prostate cancer. Microorganisms or their metabolites may affect the occurrence and metastasis of cancer cells or regulate anti-cancer immune surveillance. In addition, the use of tumor microenvironment bacteria in interventional targeting therapy of tumors also shows a unique advantage. In this review, we introduce the pathway of microbiota into prostate cancer, focusing on the mechanism of microorganisms in tumorigenesis and development, as well as the prospect and significance of microorganisms as tumor biomarkers and tumor prevention and treatment.

Exploring the Inflammatory Pathogenesis of Colorectal Cancer

Colorectal cancer is one of the most commonly diagnosed cancers worldwide. Traditionally, mechanisms of colorectal cancer formation have focused on genetic alterations including chromosomal damage and microsatellite instability. In recent years, there has been a growing body of evidence supporting the role of inflammation in colorectal cancer formation. Multiple cytokines, immune cells such T cells and macrophages, and other immune mediators have been identified in pathways leading to the initiation, growth, and metastasis of colorectal cancer. Outside the previously explored mechanisms and pathways leading to colorectal cancer, initiatives have been shifted to further study the role of inflammation in pathogenesis. Inflammatory pathways have also been linked to some traditional risk factors of colorectal cancer such as obesity, smoking and diabetes, as well as more novel associations such as the gut microbiome, the gut mycobiome and exosomes. In this review, we will explore the roles of obesity and diet, smoking, diabetes, the microbiome, the mycobiome and exosomes in colorectal cancer, with a specific focus on the underlying inflammatory and metabolic pathways involved. We will also investigate how the study of colon cancer from an inflammatory background not only creates a more holistic and inclusive understanding of this disease, but also creates unique opportunities for prevention, early diagnosis and therapy.

Tumorigenic bacteria in colorectal cancer: mechanisms and treatments

Colorectal cancer (CRC) is the third most common and the second most fatal cancer. In recent years, more attention has been directed toward the role of gut microbiota in the initiation and development of CRC. Some bacterial species, such as Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis, Enterococcus faecalis, and Salmonella sp. have been associated with CRC, based upon sequencing studies in CRC patients and functional studies in cell culture and animal models. These bacteria can cause host DNA damage by genotoxic substances, including colibactin secreted by pks + Escherichia coli, B. fragilis toxin (BFT) produced by Bacteroides fragilis, and typhoid toxin (TT) from Salmonella. These bacteria can also indirectly promote CRC by influencing host-signaling pathways, such as E-cadherin/β-catenin, TLR4/MYD88/NF-κB, and SMO/RAS/p38 MAPK. Moreover, some of these bacteria can contribute to CRC progression by helping tumor cells to evade the immune response by suppressing immune cell function, creating a proinflammatory environment, or influencing the autophagy process. Treatments with the classical antibacterial drugs, metronidazole or erythromycin, the antibacterial active ingredients, M13@ Ag (electrostatically assembled from inorganic silver nanoparticles and the protein capsid of bacteriophage M13), berberine, and zerumbone, were found to inhibit tumorigenic bacteria to different degrees. In this review, we described progress in elucidating the tumorigenic mechanisms of several CRC-associated bacteria, as well as progress in developing effective antibacterial therapies. Specific bacteria have been shown to be active in the oncogenesis and progression of CRC, and some antibacterial compounds have shown therapeutic potential in bacteria-induced CRC. These bacteria may be useful as biomarkers or therapeutic targets for CRC.

Risk factor for breast cancer development under exposure to bovine leukemia virus in Colombian women: A case-control study

Viruses have been implicated in cancer development in both humans and animals. The role of viruses in cancer is typically to initiate cellular transformation through cellular DNA damage, although specific mechanisms remain unknown. Silent and long-term viral infections need to be present, in order to initiate cancer disease. In efforts to establish a causative role of viruses, first is needed to demonstrate the strength and consistency of associations in different populations. The aim of this study was to determine the association of bovine leukemia virus (BLV), a causative agent of leukemia in cattle, with breast cancer and its biomarkers used as prognosis of the severity of the disease (Ki67, HER2, hormonal receptors) in Colombian women. An unmatched, observational case-control study was conducted among women undergoing breast surgery between 2016-2018. Malignant samples (n = 75) were considered as cases and benign samples (n = 83) as controls. Nested-liquid PCR, in-situ PCR and immunohistochemistry were used for viral detection in blood and breast tissues. For the risk assessment, only BLV positive samples from breast tissues were included in the analysis. BLV was higher in cases group (61.3%) compared with controls (48.2%), with a statistically significant association between the virus and breast cancer in the unconditional logistic regression (adjusted-OR = 2.450,95%CI:1.088-5.517, p = 0.031). In this study, BLV was found in both blood and breast tissues of participants and an association between breast cancer and the virus was confirmed in Colombia, as an intermediate risk factor.

Harness the functions of gut microbiome in tumorigenesis for cancer treatment

It has been shown that gut microbiota dysbiosis leads to physiological changes and links to a number of diseases, including cancers. Thus, many cancer categories and treatment regimens should be investigated in the context of the microbiome. Owing to the availability of metagenome sequencing and multiomics studies, analyses of species characterization, host genetic changes, and metabolic profile of gut microbiota have become feasible, which has facilitated an exponential knowledge gain about microbiota composition, taxonomic alterations, and host interactions during tumorigenesis. However, the complexity of the gut microbiota, with a plethora of uncharacterized host‐microbe, microbe‐microbe, and environmental interactions, still contributes to the challenge of advancing our knowledge of the microbiota‐cancer interactions. These interactions manifest in signaling relay, metabolism, immunity, tumor development, genetic instability, sensitivity to cancer chemotherapy and immunotherapy. This review summarizes current studies/molecular mechanisms regarding the association between the gut microbiota and the development of cancers, which provides insights into the therapeutic strategies that could be harnessed for cancer diagnosis, treatment, or prevention.

Dietary fat, bile acid metabolism and colorectal cancer

Colorectal cancer (CRC) risk is predominantly driven by environmental factors, in particular diet. A high intake of dietary fat has been implicated as a risk factor inducing the formation of pre-neoplastic lesions (e.g., adenomatous polyps) and/or exacerbating colonic tumorigenesis. Recent data attributed the tumor-promoting activity of high-fat diets to their effects on gut microbiota composition and metabolism, in particular with regard to bile acids. Bile acids are synthesized in the liver in response to dietary fat and facilitate lipid absorption in the small intestine. The majority of bile acids is re-absorbed during small intestinal transit and subjected to enterohepatic circulation. Bile acids entering the colon undergo complex biotransformation performed by gut bacteria, resulting in secondary bile acids that show tumor-promoting activity. Excessive dietary fat leads to high levels of secondary bile acids in feces and primes the gut microbiota to bile acid metabolism. This promotes an altered overall bile acid pool, which activates or restricts intestinal and hepatic cross-signaling of the bile acid receptor, farnesoid X receptor (FXR). Recent studies provided evidence that FXR is a main regulator of bile acid-mediated effects on intestinal tumorigenesis integrating dietary, microbial and genetic risk factors for CRC. Selective FXR agonist or antagonist activity by specific bile acids depends on additional factors (e.g., bile acid concentration, composition of bile acid pool, genetic instability of cells) and, thus, may differ in healthy and tumorigenic conditions in the intestine. In conclusion, fat-mediated alterations of the gut microbiota link bile acid metabolism to CRC risk and colonic tumorigenesis, exemplifying how gut microbial co-metabolism affects colon health.

Revisiting social MPE: an integration of molecular pathological epidemiology and social science in the new era of precision medicine

INTRODUCTION

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary area examining the relationships between various exposures and pathogenic signatures of diseases. In line with the accelerating advancements in MPE, social science and its health-related interdisciplinary areas have also developed rapidly. Accumulating evidence indicates the pathological role of social-demographic factors. We therefore initially proposed social MPE in 2015, which aims to elucidate etiological roles of social-demographic factors and address health inequalities globally. With the ubiquity of molecular diagnosis, there are ample opportunities for researchers to utilize and develop the social MPE framework.

AREAS COVERED

Molecular subtypes of breast cancer have been investigated rigorously for understanding its etiologies rooted from social factors. Emerging evidence indicates pathogenic heterogeneity of neurological disorders such as Alzheimer's disease. Presenting specific patterns of social-demographic factors across different molecular subtypes should be promising for advancing the screening, prevention, and treatment strategies of those heterogeneous diseases. This article rigorously reviewed literatures investigating differences of race/ethnicity and socioeconomic status across molecular subtypes of breast cancer and Alzheimer's disease to date.

EXPERT OPINION

With advancements of the multi-omics technologies, we foresee a blooming of social MPE studies, which can address health disparities, advance personalized molecular medicine, and enhance public health.

Multidimensional role of bacteria in cancer: Mechanisms insight, diagnostic, preventive and therapeutic potential

The active role of bacteria in oncogenesis has long been a topic of debate. Although, it was speculated to be a transmissible cause of cancer as early as the 16th-century, yet the idea about the direct involvement of bacteria in cancer development has only been explored in recent decades. More recently, several studies have uncovered the mechanisms behind the carcinogenic potential of bacteria which are inflammation, immune evasion, pro-carcinogenic metabolite production, DNA damage and genomic instability. On the other side, the recent development on the understanding of tumor microenvironment and technological advancements has turned this enemy into an ally. Studies using bacteria for cancer treatment and detection have shown noticeable effects. Therapeutic abilities of bioengineered live bacteria such as high specificity, selective cytotoxicity to cancer cells, responsiveness to external signals and control after ingestion have helped to overcome the challenges faced by conventional cancer therapies and highlighted the bacterial based therapy as an ideal approach for cancer treatment. In this review, we have made an effort to compile substantial evidence to support the multidimensional role of bacteria in cancer. We have discussed the multifaceted role of bacteria in cancer by highlighting the wide impact of bacteria on different cancer types, their mechanisms of actions in inducing carcinogenicity, followed by the diagnostic and therapeutic potential of bacteria in cancers. Moreover, we have also highlighted the existing gaps in the knowledge of the association between bacteria and cancer as well as the limitation and advantage of bacteria-based therapies in cancer. A better understanding of these multidimensional roles of bacteria in cancer can open up the new doorways to develop early detection strategies, prevent cancer, and develop therapeutic tactics to cure this devastating disease.

Early technology assessment of using whole genome sequencing in personalized oncology

Introduction: Personalized medicine-based treatments in advanced cancer hold the promise to offer substantial health benefits to genetic subgroups, but require efficient biomarker-based patient stratification to match the right treatment and may be expensive. Standard molecular diagnostics are currently very heterogeneous, and tests are often performed sequentially. The alternative to whole genome sequencing (WGS) i.e. simultaneously testing for all relevant DNA-based biomarkers thereby allowing immediate selection of the most optimal therapy, is more costly than current techniques. In the current implementation stage, it is important to explore the added value and cost-effectiveness of using WGS on a patient level and to assess optimal introduction of WGS on the level of the healthcare system.Areas covered: First, an overview of current worldwide initiatives concerning the use of WGS in clinical practice for cancer diagnostics is given. Second, a comprehensive, early health technology assessment (HTA) approach of evaluating WGS in the Netherlands is described, relating to the following aspects: diagnostic value, WGS-based treatment decisions, assessment of long-term health benefits and harms, early cost-effectiveness modeling, nation-wide organization, and Ethical, Legal and Societal Implications.Expert opinion: This study provides evidence to guide further development and implementation of WGS in clinical practice and the healthcare system.

ABO Blood Group and Risk of Pancreatic Carcinogenesis in Intraductal Papillary Mucinous Neoplasms

BACKGROUND

ABO blood group has been associated with risks of various malignancies, including pancreatic cancer. No study has evaluated the association of ABO blood group with incidence of pancreatic carcinogenesis during follow-up of patients with intraductal papillary mucinous neoplasms (IPMN).

METHODS

Among 3,164 patients diagnosed with pancreatic cysts at the University of Tokyo (Tokyo, Japan) from 1994 through 2019, we identified 1,815 patients with IPMN with available data on ABO blood group. We studied the association of ABO blood group with incidence of pancreatic carcinoma, overall and by carcinoma types [IPMN-derived carcinoma or concomitant pancreatic ductal adenocarcinoma (PDAC)]. Utilizing competing-risks proportional hazards models, we estimated subdistribution hazard ratios (SHR) for incidence of pancreatic carcinoma with adjustment for potential confounders, including cyst characteristics.

RESULTS

During 11,518 person-years of follow-up, we identified 97 patients diagnosed with pancreatic carcinoma (53 with IPMN-derived carcinoma and 44 with concomitant PDAC). Compared with patients with blood group O, patients with blood groups A, B, and AB had multivariable SHRs (95% confidence intervals) for pancreatic carcinoma of 2.25 (1.25-4.07; P = 0.007), 2.09 (1.08-4.05; P = 0.028), and 1.17 (0.43-3.19; P = 0.76), respectively. We observed no differential association of ABO blood group with pancreatic carcinoma incidence by carcinoma types.

CONCLUSIONS

In this large long-term study, patients with IPMN with blood group A or B appeared to be at higher risk of pancreatic carcinoma compared with those with blood group O.

IMPACT

ABO blood group can be a biomarker for pancreatic cancer risk among patients with IPMNs.

The Role of Gut Barrier Dysfunction and Microbiome Dysbiosis in Colorectal Cancer Development

Accumulating evidence indicates that breakdown of the+ protective mucosal barrier of the gut plays a role in colorectal cancer (CRC) development. Inflammation and oxidative stress in the colonic epithelium are thought to be involved in colorectal carcinogenesis and the breakdown of the integrity of the colonic barrier may increase the exposure of colonocytes to toxins from the colonic milieu, enhancing inflammatory processes and release of Reactive Oxygen Species (ROS). The aetiological importance of the gut microbiome and its composition - influenced by consumption of processed meats, red meats and alcoholic drinks, smoking, physical inactivity, obesity - in CRC development is also increasingly being recognized. The gut microbiome has diverse roles, such as in nutrient metabolism and immune modulation. However, microbial encroachment towards the colonic epithelium may promote inflammation and oxidative stress and even translocation of species across the colonic lumen. Recent research suggests that factors that modify the above mechanisms, e.g., obesity and Western diet, also alter gut microbiota, degrade the integrity of the gut protective barrier, and expose colonocytes to toxins. However, it remains unclear how obesity, lifestyle and metabolic factors contribute to gut-barrier integrity, leading to metabolic disturbance, colonocyte damage, and potentially to CRC development. This review will discuss the interactive roles of gut-barrier dysfunction, microbiome dysbiosis, and exposure to endogenous toxins as another mechanism in CRC development, and how biomarkers of colonic mucosal barrier function may provide avenues for disease, prevention and detection.

Clinical effects of ursodeoxycholic acid on patients with ulcerative colitis may improve via the regulation of IL-23-IL-17 axis and the changes of the proportion of intestinal microflora

BACKGROUND

We aimed to evaluate the therapeutic effect of additional ursodeoxycholic acid (UDCA) with mesalazine, compared to mesalazine alone in patients with ulcerative colitis (UC). The mechanism was evaluated by monitoring the changes of IL-23-IL-17 axis and the intestinal microflora.

METHODS

In this prospective, single center study, patients with UC were randomly assigned to the Mesalazine group (n=20) or the UDCA + Mesalazine group (n=20). Mayo score and Inflammatory Bowel Disease Questionnaire (IBDQ), and fecal samples for 16S rRNA sequencing and blood samples for IL-23 and IL-17 ELISA were collected for analysis.

RESULTS

Mayo scores and IBDQ score of the UDCA + Mesalazine group were significantly better than those of the Mesalazine group (P = 0.015 and P < 0.001, respectively). At post-treatment week 4, IL-23 and IL-17 levels were significantly lower in the UDCA + Mesalazine group compared to those in the Mesalazine group (both P < 0.038). In patients with UC after treatment, Firmicutes in the UDCA + Mesalazine group was higher than those in the Mesalazine group (P < 0.001). The UDCA + Mesalazine group showed lower percentage of Proteobacteria compared to those in the Mesalazine group (P < 0.001).

CONCLUSION

Additional UDCA could provide better therapeutic effects than mesalazine alone, possibly due to the change of IL-23 and IL-17 and the proportional distribution of intestinal microflora.

Research Progress of Pancreas-Related Microorganisms and Pancreatic Cancer

Pancreatic cancer is one of the most common digestive system cancers. Early diagnosis is difficult owing to the lack of specific symptoms and reliable biomarkers. The cause of pancreatic cancer remains ambiguous. Smoking, drinking, new-onset diabetes, and chronic pancreatitis have been proven to be associated with the occurrence of pancreatic cancer. In recent years, a large number of studies have clarified that a variety of microorganisms colonized in pancreatic cancer tissues are also closely related to the occurrence and development of pancreatic cancer, and the specific mechanisms include inflammatory induction, immune regulation, metabolism, and microenvironment changes caused by microorganism. The mechanism of action of the pancreatic colonized microbiome in the tumor microenvironment, as well as immunotherapy approaches require further study in order to find more evidence to explain the complex relationship between the pancreatic colonized microbiome and PDAC. Relevant studies targeting the microbiome may provide insight into the mechanisms of PDAC development and progression, improving treatment effectiveness and overall patient prognosis. In this article, we focus on the research relating to the microorganisms colonized in pancreatic cancer tissues, including viruses, bacteria, and fungi. We also highlight the microbial diversity in the occurrence, invasion, metastasis, treatment, and prognosis of pancreatic cancer in order to elucidate its significance in the early diagnosis and new therapeutic treatment of pancreatic cancer, which urgently need to be improved in clinical practice. The elimination or increase in diversity of the pancreatic microbiome is beneficial for prolonging the survival of PDAC patients, improving the response to chemotherapy drugs, and reducing tumor burden. The colonization of microorganisms in the pancreas may become a new hotspot in the diagnosis and treatment of pancreatic cancer.

Adrecizumab: an investigational agent for the biomarker-guided treatment of sepsis

Introduction: Sepsis is a major health problem with a high incidence and mortality. ADM, a free-circulating peptide mainly expressed and secreted by vascular endothelial cells, shows vasodilatory properties and causes hypotension when present in higher concentrations during sepsis. Areas covered: Adrecizumab (ADZ) (HAM 8101) is a humanized targeted therapy directed against the N-terminus of adrenomedullin (ADM). ADZ inhibits excessive circulating sepsis-induced ADM and stimulates protective effects on the endothelial barrier, and decreases interstitial vasodilatory effects. ADZ demonstrated a promising safety profile in healthy subjects in phase I studies. According to these results, a phase II proof of concept study enrolling 300 septic patients is currently in course (NCT03085758). Expert opinion: ADZ is the first humanized antibody directed against ADM. The main interest of ADZ is its potential use as a 'biomarker-guided therapy' in septic patients with high circulating ADM. ADZ is increasingly seen as a potential adjunct therapy to restore endothelial function in septic shock. A positive pivotal phase III trial is indeed needed to convince the intensive care community to prescribe ADZ in septic shock patients. Further, it would be of interest to see whether ADZ might also benefit other critical diseases such as cardiogenic shock where endothelial dysfunction has also been described.

A meta-analysis of CD274 (PD-L1) assessment and prognosis in colorectal cancer and its role in predicting response to anti-PD-1 therapy

BACKGROUND

PD-1 checkpoint inhibitors are novel therapeutic agents in colorectal cancer (CRC). Immunohistochemical staining for CD274 assessment is standardised in upper GI cancer, but not in CRC.

METHODS

Methodologies of relevant studies were scrutinized and meta-analysis of survival and CD274/PDCD1 performed. Furthermore, anti-PD-1 therapy clinical trial results in CRC were assessed with particular emphasis on CD274 assessment.

RESULTS

24 studies were included. CD274 on immune cells was associated with good prognosis. CD274 on tumour cells has heterogenous outcomes and does not meet requirements of a prognostic marker. As a marker of response to anti-PD-1 therapy, CD274 assessment is not standardised in CRC.

CONCLUSION

CD274 does not appear useful as a prognostic marker. As a marker of response to anti-PD-1 therapy, assessment methodology requires standardisation. As the Combined Positive Score (CPS) is used in upper GI cancer, this seems a logical method to adopt. Thresholds for CRC remain to be determined.

Cervicovaginal microbiota dysbiosis correlates with HPV persistent infection

HPV persistent infection is a main event leading to the development of cervical intraepithelial neoplasia and cervical cancer. Earlier to distinguish HPV persistent and transient infection is meaningful but the methods are limited. This study used 16S rDNA sequencing to determine the cervicovaginal microbiota of HPV persistent infection, transient infection and health women. Sequences analysis was performed and according to subsequent statistical analysis, the structure of cervicovaginal microbiota of healthy and transient infection individuals is relatively single, Firmicutes occupy the main composition. However, that of the HPV persistent infection presented a complicated trend and the abundance of Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria was higher. The significance p-values of the average species abundance of Firmicutes, Proteobacteria and Bacteroides between HPV persistent and transient infection groups were 0.003, 0.018 and 0.005, respectively. The study also found 36 biomarkers of cervicovaginal microbiota dysbiosis for LDA score>4 among different groups. At genus level, Prevotella, Sphingomonas and Anaerococcus correlated with HPV persistent infection. At species level, Lactobacillus iners correlated with HPV transient infection. Besides, local immune microenvironment was changed with cervicovaginal microbiota dysbiosis. Interleukin-6 and TNF-α were significantly upregulated in cervical secretions from HPV persistent infection compared with those from transient infection and healthy women. Peripheral blood Regulatory T cells and myeloid-derived suppressor cells in patients with HPV persistent infection were also significantly increased. In conclusion, this study identified cervicovaginal microbiota dysbiosis closely related to HPV persistent infection, which provided a new idea and method for the prevention of cervical cancer.

The microbiome, genetics, and gastrointestinal neoplasms: the evolving field of molecular pathological epidemiology to analyze the tumor-immune-microbiome interaction

Metagenomic studies using next-generation sequencing technologies have revealed rich human intestinal microbiome, which likely influence host immunity and health conditions including cancer. Evidence indicates a biological link between altered microbiome and cancers in the digestive system. Escherichia coli and Bacteroides fragilis have been found to be enriched in colorectal mucosal tissues from patients with familial adenomatous polyposis that is caused by germline APC mutations. In addition, recent studies have found enrichment of certain oral bacteria, viruses, and fungi in tumor tissue and fecal specimens from patients with gastrointestinal cancer. An integrative approach is required to elucidate the role of microorganisms in the pathogenic process of gastrointestinal cancers, which develop through the accumulation of somatic genetic and epigenetic alterations in neoplastic cells, influenced by host genetic variations, immunity, microbiome, and environmental exposures. The transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to link germline genetics and environmental factors (including diet, lifestyle, and pharmacological factors) to pathologic phenotypes. The integration of microbiology into the MPE model (microbiology-MPE) can contribute to better understanding of the interactive role of environment, tumor cells, immune cells, and microbiome in various diseases. We review major clinical and experimental studies on the microbiome, and describe emerging evidence from the microbiology-MPE research in gastrointestinal cancers. Together with basic experimental research, this new research paradigm can help us to develop new prevention and treatment strategies for gastrointestinal cancers through targeting of the microbiome.

Molecular Immunotherapy: Promising Approach to Treat Metastatic Colorectal Cancer by Targeting Resistant Cancer Cells or Cancer Stem Cells

The immune system is able to recognize and eliminate tumor cells. Some tumors, including colorectal cancer (CRC), induce immune tolerance via different mechanisms of “immunoediting” and “immune evasion” and can thus escape immune surveillance. The impact of immunotherapy on cancer has been investigated for many years, but so far, the application was limited to few cancer types. Immuno-oncological therapeutic strategies against metastatic colorectal cancer (mCRC), the adaptive immune system activating approaches, offer a high potential for adaptation to the great heterogeneity of CRC. Moreover, novel treatment approaches are currently being tested that might specifically target the disease initiating and maintaining population of colorectal cancer stem cells (CSCs). In this review, we aim to summarize the current state of immune-oncology and tumor immunotherapy of patients with mCRC and discuss different therapeutic modalities that focus on the activation of tumor-specific T-cells and their perspectives such as tumor vaccination, checkpoint inhibition, and adoptive T-cell transfer or on the eradication of colorectal CSCs.

Management of the Adverse Effects of Immune Checkpoint Inhibitors

By increasing the activity of the immune system, immune checkpoint inhibitors (ICPI) can have adverse inflammatory effects, which are referred to as immune-related adverse effects (irAEs). In this review, we present the recommendations for the appropriate identification and treatment of irAEs associated with ICPI to increase the safety and effectiveness of therapy with these immuno-oncological drugs. Several guidelines to manage irAEs adopted by different American and European societies in the field of oncology were identified. A narrative review of the several strategies adopted to manage irAEs was performed. With close clinical surveillance, ICPI can be used even in patients who have mild irAEs. Moderate to severe events require early detection and appropriate treatment, particularly in patients with a history of transplantation or pre-existing autoimmune disease. In most cases, adverse reactions can be treated with the interruption of treatment and/or supportive therapy, which includes, in serious adverse reactions, the administration of immunosuppressants. The identification and treatment of irAEs in the early stages may allow patients to resume therapy with ICPI. This review is an instrument to support healthcare professionals involved in the treatment and monitoring of patients who are administered ICPI, contributing to the timely identification and management of irAEs.

Influence of Iron on the Gut Microbiota in Colorectal Cancer

Perturbations of the colonic microbiota can contribute to the initiation and progression of colorectal cancer, leading to an increase in pathogenic bacteria at the expense of protective bacteria. This can contribute to disease through increasing carcinogenic metabolite/toxin production, inducing inflammation, and activating oncogenic signaling. To limit disease progression, external factors that may influence the colonic microbiota need to be considered in patients with colorectal cancer. One major factor that can influence the colonic microbiota is iron. Iron is an essential micronutrient that is required by both prokaryotes and eukaryotes for cellular function. Most pathogenic bacteria have heightened iron acquisition mechanisms and therefore tend to outcompete protective bacteria for free iron. Colorectal cancer patients often present with anemia due to iron deficiency, and thus they require iron therapy. Depending upon the route of administration, iron therapy has the potential to contribute to a procarciongenic microbiota. Orally administered iron is the common treatment for anemia in these patients but can lead to an increased gut iron concentration. This suggests the need to reassess the route of iron therapy in these patients. Currently, this has only been assessed in murine studies, with human trials being necessary to unravel the potential microbial outcomes of iron therapy.

Immune Landscape in Tumor Microenvironment: Implications for Biomarker Development and Immunotherapy

Integration of the tumor microenvironment as a fundamental part of the tumorigenic process has undoubtedly revolutionized our understanding of cancer biology. Increasing evidence indicates that neoplastic cells establish a dependency relationship with normal resident cells in the affected tissue and, furthermore, develop the ability to recruit new accessory cells that aid tumor development. In addition to normal stromal and tumor cells, this tumor ecosystem includes an infiltrated immune component that establishes complex interactions that have a critical effect during the natural history of the tumor. The process by which immune cells modulate tumor progression is known as immunoediting, a dynamic process that creates a selective pressure that finally leads to the generation of immune-resistant cells and the inability of the immune system to eradicate the tumor. In this context, the cellular and functional characterization of the immune compartment within the tumor microenvironment will help to understand tumor progression and, ultimately, will serve to create novel prognostic tools and improve patient stratification for cancer treatment. Here we review the impact of the immune system on tumor development, focusing particularly on its clinical implications and the current technologies used to analyze immune cell diversity within the tumor.

Cancer Risk Studies and Priority Areas for Cancer Risk Appraisal in Uganda

Background

Research into aetiologies and prevention of the commonest cancers and implementation of primary and secondary prevention can reduce cancer risk and improve quality of life. Moreover, monitoring the prevalence of cancer risk factors in a specific population helps guide cancer prevention and early detection efforts and national cancer control programming.

Objective

This article aims to provide the scope and findings of cancer risk studies conducted in Uganda to guide researchers, health-care professionals, and policymakers.

Methods

Between November 2019 to January 2020, we searched peer-reviewed published articles in Pubmed, EMBASE and Cochrane Library (Cochrane central register of controlled trials-CENTRAL). We followed the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - the PRISMA. The primary focus was to identify cancer risk and prevention studies conducted in Uganda and published in peer-reviewed journals from January 2000 and January 2020. We used key Boolean search terms with their associated database strings.

Results

We identified 416 articles, screened 269 non-duplicate articles and obtained 77 full-text articles for review. Out of the 77 studies, we identified one (1%) randomized trial, two (2.5%) retrospective cohort studies and 14 (18%) case-control studies, 46 (60%) cross-sectional studies, five (6.4%) ecological studies, three panel studies (4%) and six (8%) qualitative studies. Cervical cancer was the most studied type of cancer in Uganda (23.4%, n = 18 studies), followed by lymphomas - both Hodgkin and Non-Hodgkin sub-types (20.7%), n = 16 studies) and breast cancer (15.6%, n = 12 studies). In lymphoma studies, Burkitt lymphoma was the most studied type of lymphoma (76%, n = 13 studies). The studies concentrated on specific cancer risk awareness, risk perceptions, attitudes, uptake of screening, uptake of human papillomavirus vaccination, the prevalence of some of the known cancer risk factors and obstacles to accessing screening services.

Conclusion

The unmet need for comprehensive cancer risk and prevention studies is enormous in Uganda. Future studies need to comprehensively investigate the known and putative cancer risk factors and prioritize the application of the higher-hierarchy evidence-generating epidemiological studies to guide planning of the national cancer control program.

Body composition measured by computed tomography is associated with colorectal cancer survival, also in early-stage disease

Background: Cachexia and sarcopenia are associated with poor survival after colorectal cancer (CRC) diagnosis. Computed tomography (CT) can be used to measure aspects of cachexia including sarcopenia, myosteatosis and the amount of subcutaneous and visceral adipose tissue. The aim of this study was to relate CT-based body composition variables with survival outcomes in CRC.Material and methods: In this population-based, retrospective cohort study, CT scans of 974 patients with pathological stages I-IV CRCs, collected at or very near diagnosis (years 2000-2016), were used to measure cross-sectional fat and muscle tissue areas. Body composition variables based on these measurements were assessed in relation to tumor stage and site and cancer-specific survival in stages I-III CRC (n = 728) using Cox proportional hazards models and Kaplan-Meier estimators.Results: Sarcopenia was associated with decreased cancer-specific survival, especially in patients with stages I-II tumors. The hazard ratio (HR) for the lowest versus highest tertile of skeletal muscle index (SMI) was 1.67; 95% confidence interval (CI), 1.08-2.58 for all stages, and HR 2.22; 95% CI 1.06-4.68, for stages I-II. Myosteatosis was also associated with decreased cancer-specific survival [(HR 2.03; 95% CI 1.20-3.34 for the lowest versus the highest tertile of skeletal muscle radiodensity (SMR)]. SMI and SMR were lower in patients with right-sided CRC, independent of age and sex. No adipose tissue measurement was significantly associated with cancer-specific survival.Conclusion: In concordance with previous studies, sarcopenia and myosteatosis were associated with decreased cancer-specific survival. The strong association between sarcopenia and poor cancer-specific survival in early-stage disease could have clinical implications for personalizing therapy decisions, including nutritional support.

The NF-κB Signaling Pathway, the Microbiota, and Gastrointestinal Tumorigenesis: Recent Advances

Gastrointestinal (GI) cancers, especially gastric cancer and colorectal cancer (CRC), represent a major global health burden. A large population of microorganisms residing in the GI tract regulate physiological processes, such as the immune response, metabolic balance, and homeostasis. Accumulating evidence has revealed the alteration of microbial communities in GI tumorigenesis. Experimental studies in cell lines and animal models showed the functional roles and molecular mechanisms of several bacteria in GI cancers, including Helicobacter pylori in gastric cancer as well as Fusobacterium nucleatum, Escherichia coli, Peptostreptococcus anaerobius, and Bacteroides fragilis in CRC. The transcriptional factor NF-κB plays a crucial role in the host response to microbial infection through orchestrating innate and adaptive immune functions. Moreover, NF-κB activity is linked to GI cancer initiation and development through its induction of chronic inflammation, cellular transformation and proliferation. Here, we provide an overview and discussion of modulation of the NF-κB signaling pathway by microbiota, especially infectious bacteria, in GI tumorigenesis, with a major focus on gastric cancer and CRC.

Human microbiome and prostate cancer development: current insights into the prevention and treatment

The huge communities of microorganisms that symbiotically colonize humans are recognized as significant players in health and disease. The human microbiome may influence prostate cancer development. To date, several studies have focused on the effect of prostate infections as well as the composition of the human microbiome in relation to prostate cancer risk. Current studies suggest that the microbiota of men with prostate cancer significantly differs from that of healthy men, demonstrating that certain bacteria could be associated with cancer development as well as altered responses to treatment. In healthy individuals, the microbiome plays a crucial role in the maintenance of homeostasis of body metabolism. Dysbiosis may contribute to the emergence of health problems, including malignancy through affecting systemic immune responses and creating systemic inflammation, and changing serum hormone levels. In this review, we discuss recent data about how the microbes colonizing different parts of the human body including urinary tract, gastrointestinal tract, oral cavity, and skin might affect the risk of developing prostate cancer. Furthermore, we discuss strategies to target the microbiome for risk assessment, prevention, and treatment of prostate cancer.

Multifaceted p21 in carcinogenesis, stemness of tumor and tumor therapy

Cancer cells possess metabolic properties that are different from those of benign cells. p21, encoded by CDKN1A gene, also named p21^Cip1/WAF1, was first identified as a cyclin-dependent kinase regulator that suppresses cell cycle G1/S phase and retinoblastoma protein phosphorylation. CDKN1A (p21) acts as the downstream target gene of TP53 (p53), and its expression is induced by wild-type p53 and it is not associated with mutant p53. p21 has been characterized as a vital regulator that involves multiple cell functions, including G1/S cell cycle progression, cell growth, DNA damage, and cell stemness. In 1994, p21 was found as a tumor suppressor in brain, lung and colon cancer by targeting p53 and was associated with tumorigenesis and metastasis. Notably, p21 plays a significant role in tumor development through p53-dependent and p53-independent pathways. In addition, expression of p21 is closely related to the resting state or terminal differentiation of cells. p21 is also associated with cancer stem cells and acts as a biomarker for such cells. In cancer therapy, given the importance of p21 in regulating the G1/S and G2 check points, it is not surprising that p21 is implicated in response to many cancer treatments and p21 promotes the effect of oncolytic virotherapy.

Gut microbiota contributes towards immunomodulation against cancer: New frontiers in precision cancer therapeutics

The microbiota influences human health and the development of diverse diseases, including cancer. Microbes can influence tumor initiation and development in either a positive or negative manner. In addition, the composition of the gut microbiota affects the efficacy and toxicity of cancer therapeutics as well as therapeutic resistance. The striking impact of microbiota on oncogenesis and cancer therapy provides compelling evidence to support the notion that manipulating microbial networks represents a promising strategy for treating and preventing cancer. Specific microbes or the microbial ecosystem can be modified via a multiplicity of processes, and therapeutic methods and approaches have been evolving. Microbial manipulation can be applied as an adjunct to traditional cancer therapies such as chemotherapy and immunotherapy. Furthermore, this approach displays great promise as a stand-alone therapy following the failure of standard therapy. Moreover, such strategies may also benefit patients by avoiding the emergence of toxic side effects that result in treatment discontinuation. A better understanding of the host-microbial ecosystem in patients with cancer, together with the development of methodologies for manipulating the microbiome, will help expand the frontiers of precision cancer therapeutics, thereby improving patient care. This review discusses the roles of the microbiota in oncogenesis and cancer therapy, with a focus on efforts to harness the microbiota to fight cancer.

The urgent need for integrated science to fight COVID-19 pandemic and beyond

The COVID-19 pandemic has become the leading societal concern. The pandemic has shown that the public health concern is not only a medical problem, but also affects society as a whole; so, it has also become the leading scientific concern. We discuss in this treatise the importance of bringing the world's scientists together to find effective solutions for controlling the pandemic. By applying novel research frameworks, interdisciplinary collaboration promises to manage the pandemic's consequences and prevent recurrences of similar pandemics.

Smoking Status at Diagnosis and Colorectal Cancer Prognosis According to Tumor Lymphocytic Reaction

Background

Smoking has been associated with worse colorectal cancer patient survival and may potentially suppress the immune response in the tumor microenvironment. We hypothesized that the prognostic association of smoking behavior at colorectal cancer diagnosis might differ by lymphocytic reaction patterns in cancer tissue.

Methods

Using 1474 colon and rectal cancer patients within 2 large prospective cohort studies (Nurses' Health Study and Health Professionals Follow-up Study), we characterized 4 patterns of histopathologic lymphocytic reaction, including tumor-infiltrating lymphocytes (TILs), intratumoral periglandular reaction, peritumoral lymphocytic reaction, and Crohn's-like lymphoid reaction. Using covariate data of 4420 incident colorectal cancer patients in total, an inverse probability weighted multivariable Cox proportional hazards regression model was conducted to adjust for selection bias due to tissue availability and potential confounders, including tumor differentiation, disease stage, microsatellite instability status, CpG island methylator phenotype, long interspersed nucleotide element-1 methylation, and KRAS, BRAF, and PIK3CA mutations.

Results

The prognostic association of smoking status at diagnosis differed by TIL status. Compared with never smokers, the multivariable-adjusted colorectal cancer-specific mortality hazard ratio for current smokers was 1.50 (95% confidence interval = 1.10 to 2.06) in tumors with negative or low TIL and 0.43 (95% confidence interval = 0.16 to 1.12) in tumors with intermediate or high TIL (2-sided P _interaction = .009). No statistically significant interactions were observed in the other patterns of lymphocytic reaction.

Conclusions

The association of smoking status at diagnosis with colorectal cancer mortality may be stronger for carcinomas with negative or low TIL, suggesting a potential interplay of smoking and lymphocytic reaction in the colorectal cancer microenvironment.

Association of autophagy status with amount of Fusobacterium nucleatum in colorectal cancer

Fusobacterium nucleatum (F. nucleatum), which has been associated with colorectal carcinogenesis, can impair anti-tumour immunity, and actively invade colon epithelial cells. Considering the critical role of autophagy in host defence against microorganisms, we hypothesised that autophagic activity of tumour cells might influence the amount of F. nucleatum in colorectal cancer tissue. Using 724 rectal and colon cancer cases within the Nurses' Health Study and the Health Professionals Follow-up Study, we evaluated autophagic activity of tumour cells by immunohistochemical analyses of BECN1 (beclin 1), MAP1LC3 (LC3), and SQSTM1 (p62) expression. We measured the amount of F. nucleatum DNA in tumour tissue by quantitative polymerase chain reaction (PCR). We conducted multivariable ordinal logistic regression analyses to examine the association of tumour BECN1, MAP1LC3, and SQSTM1 expression with the amount of F. nucleatum, adjusting for potential confounders, including microsatellite instability status; CpG island methylator phenotype; long-interspersed nucleotide element-1 methylation; and KRAS, BRAF, and PIK3CA mutations. Compared with BECN1-low cases, BECN1-intermediate and BECN1-high cases were associated with lower amounts of F. nucleatum with odds ratios (for a unit increase in three ordinal categories of the amount of F. nucleatum) of 0.54 (95% confidence interval, 0.29-0.99) and 0.31 (95% confidence interval, 0.16-0.60), respectively (Ptrend  < 0.001 across ordinal BECN1 categories). Tumour MAP1LC3 and SQSTM1 levels were not significantly associated with the amount of F. nucleatum (Ptrend  > 0.06). Tumour BECN1, MAP1LC3, and SQSTM1 levels were not significantly associated with patient survival (Ptrend  > 0.10). In conclusion, tumour BECN1 expression is inversely associated with the amount of F. nucleatum in colorectal cancer tissue, suggesting a possible role of autophagy in the elimination of invasive microorganisms. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

An integrated analysis of lymphocytic reaction, tumour molecular characteristics and patient survival in colorectal cancer

BACKGROUND

Histological lymphocytic reaction is regarded as an independent prognostic marker in colorectal cancer. Considering the lack of adequate statistical power, adjustment for selection bias and comprehensive tumour molecular data in most previous studies, we investigated the strengths of the prognostic associations of lymphocytic reaction in colorectal carcinoma by utilising an integrative database of two prospective cohort studies.

METHODS

We examined Crohn's-like reaction, intratumoural periglandular reaction, peritumoural reaction and tumour-infiltrating lymphocytes in 1465 colorectal carcinoma cases. Using covariate data of 4420 colorectal cancer cases in total, inverse probability-weighted Cox proportional hazard regression model was used to control for selection bias (due to tissue availability) and potential confounders, including stage, MSI status, LINE-1 methylation, PTGS2 and CTNNB1 expression, KRAS, BRAF and PIK3CA mutations, and tumour neoantigen load.

RESULTS

Higher levels of each lymphocytic reaction component were associated with better colorectal cancer-specific survival (Ptrend < 0.002). Compared with cases with negative/low intratumoural periglandular reaction, multivariable-adjusted HRs were 0.55 (95% CI, 0.42-0.71) in cases with intermediate reaction and 0.20 (95% CI, 0.12-0.35) in cases with high reaction. These relationships were consistent in strata of MSI status or neoantigen loads (Pinteraction > 0.2).

CONCLUSIONS

The four lymphocytic reaction components are prognostic biomarkers in colorectal carcinoma.

Serum Immunoglobulin G Is Associated With Decreased Risk of Pancreatic Cancer in the Swedish AMORIS Study

Background: Emerging evidence points to potential roles of the humoral immune responses in the development of pancreatic cancer. Epidemiological studies have suggested involvement of viral and bacterial infections in pancreatic carcinogenesis. Experimental studies have reported high expression levels of antigens in pancreatic cancer cells. Therefore, we aimed to investigate the role of different components of humoral immunity in the context of pancreatic cancer. We evaluated associations between pre-diagnostic serum markers of the overall humoral immune system [immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM)], and the risk of pancreatic cancer in the Swedish Apolipoprotein-related MORtality RISk (AMORIS) study.

Methods: We selected all participants (≥20 years old) with baseline measurements of IgA, IgG or IgM (n = 41,900, 136,221, and 29,919, respectively). Participants were excluded if they had a history of chronic pancreatitis and individuals were free from pancreatic cancer at baseline. Multivariate Cox proportional hazards regression was used to estimate risk of pancreatic cancer for medical cut-offs of IgA, IgG, and IgM.

Results: Compared to the reference level of 6.10–14.99 g/L, risk of pancreatic cancer was elevated among those with IgG levels <6.10 g/L [HR: 1.69 (95% CI 0.99–2.87)], and an inverse association was observed among those with IgG levels ≥15.00 g/L [0.82 (95% CI 0.64–1.05); Ptrend = 0.027]. The association appeared to be stronger for women than men [HR: 0.64 (95% CI 0.43–0.97) and 0.95 (95% CI 0.69–1.29), respectively]. No associations were observed with IgA or IgM.

Conclusion: An inverse association was observed between pre-diagnostic serum levels of IgG and risk of pancreatic cancer. Our findings highlight the need to further investigate the role of immune response in pancreatic cancer etiology.