Strategies for prevention of gastrointestinal cancers in developing countries: a systematic review

From molecular pathogenesis to therapy: Unraveling non-coding RNAs/DNMT3A axis in human cancers

Cancer is a comprehensive classification encompassing more than 100 forms of malignancies that manifest in diverse tissues within the human body. Recent studies have provided evidence that aberrant epigenetic modifications are pivotal indicators of cancer. Epigenetics encapsulates DNA methyltransferases as a crucial class of modifiers. DNMTs, including DNMT3A, assume central roles in DNA methylation processes that orchestrate normal biological functions, such as gene transcription, predominantly in mammals. Typically, deviations in DNMT3A function engender distortions in factors that drive tumor growth and progression, thereby exacerbating the malignant phenotype of tumors. Consequently, such abnormalities pose significant challenges in cancer therapy because they impede treatment efficacy. Non-coding RNAs (ncRNAs) represent a group of RNA molecules that cannot encode functional proteins. Recent investigation attests to the crucial significance of regulatory ncRNAs in epigenetic regulation. Notably, recent reports have illuminated the complex interplay between ncRNA expression and epigenetic regulatory machinery, including DNMT3A, particularly in cancer. Recent findings have demonstrated that miRNAs, namely miR-770-5p, miR-101, and miR-145 exhibit the capability to target DNMT3A directly, and their aberration is implicated in diverse cellular abnormalities that predispose to cancer development. This review aims to articulate the interplay between DNMT3A and the ncRNAs, focusing on its impact on the development and progression of cancer, cancer therapy resistance, cancer stem cells, and prognosis. Importantly, the emergence of such reports that suggest a connection between DNMT3A and ncRNAs in several cancers indicates that this connecting axis offers a valuable target with significant therapeutic potential that might be exploited for cancer management.

The Trend of Years of Life Lost due to Gastrointestinal Cancers in Fars (Iran) 2004-2019

Background

Gastrointestinal cancers can cause major health problems globally since their burden is increasing in many countries. We aimed to investigate the trend of years of life lost due to gastrointestinal cancers in Fars Province, southern Iran during the 2004-2019.

Methods

In this cross-sectional survey study, we obtained the information regarding all deaths due to gastrointestinal cancers in Fars Province from the electronic population-based death registration system (EDRS). Years of Life Lost (YLL) was calculated using the YLL template of 2015 by the WHO. To examine the trend for different years, join point regression based on the log-linear model was used. Joinpoint regression analysis describes changing trends over successive periods of time and the increasing or decreasing rate within each period.

Results

During the years of 2004-2019, 9742 deaths due to gastrointestinal cancers occurred in Fars Province. 6013 (61.72%) cases were male and 3729 (38.28%) cases were female (Male / Female Sex Ratio: 1.61). Overall, 4152 cases (42.63%) were due to gastric cancer and 2112 cases (21.68%) were due to liver cancer. Total years of life lost due to premature death from gastrointestinal cancers during the 16-year study period was 73565 yr (2.33 per 1000 persons) in men, 52766 yr (1.71 per 1000 persons) in women, and 126331 yr (2.02 per 1000 persons) in both sexes.

Conclusion

Among all cancers, the highest mortality rates in both sexes belong to gastric cancer. This study showed the trend of YLL rate of malignant neoplasms of liver and intrahepatic bile ducts, esophagus, oral cavity, and colon cancer were increasing in both sexes, however, the trend of YLL rate for malignant neoplasms of the small intestine was decreasing in both sexes. Variation of GI cancers patterns and trends around the Fars Province indicated that a more comprehensive control plan is needed to control these variations.

Prevention of malignant digestive system tumors should focus on the control of chronic inflammation

Chronic inflammation, through a variety of mechanisms, plays a key role in the occurrence and development of digestive system malignant tumors (DSMTs). In this study, we feature and provide a comprehensive understanding of DSMT prevention strategies based on preventing or controlling chronic inflammation. The development and evaluation of cancer prevention strategies is a longstanding process. Cancer prevention, especially in the early stage of life, should be emphasized throughout the whole life course. Issues such as the time interval for colon cancer screening, the development of direct-acting antiviral drugs for liver cancer, and the Helicobacter pylori vaccine all need to be explored in long-term, large-scale experiments in the future.

The Role of National Specialist Societies in Influencing Transformational Change in Low-Middle Income Countries - Reflections on the Model of Implementation for a National Endoscopy Training Programme in Bangladesh

The British Society of Gastroenterology (BSG) and the Bangladesh Gastroenterology Society (BGS) have collaborated on an endoscopy training programme, which has grown up over the past decade from a small scheme borne out of the ideas of consultant gastroenterologists in Swansea, South Wales (United Kingdom) to improve gastroenterology services in Bangladesh to become a formalised training programme with broad reach. In this article, we document the socioeconomic and historical problems that beset Bangladesh, the current training needs of doctors and how the BSG-BGS collaboration has made inroads into changing outcomes both for gastroenterologists in Bangladesh, but also for the populations they serve.

IL10 hypomethylation is associated with the risk of gastric cancer

Interleukin-10 (IL10), a pleiotropic cytokine secreted by type-2 helper (Th2) T cells, contributes to the oncogenic activation or inactivation of tumor-suppressor genes. The present study investigated whether hypomethylation of IL10 CpG island (CGI) was associated with the risk of developing gastric cancer (GC) and the prognosis of patients with GC. A fragment (hg18, chr1: 206945638-206945774) at the CGI of IL10 was selected for the present methylation assay. Quantitative methylation-specific PCR was used to evaluate the methylation of IL10 CGI in 117 tumor samples from patients with GC. The results demonstrated that IL10 CGI methylation was significantly lower in the tumor tissues compared with that in the paired adjacent non-tumor tissues (median percentage of methylated reference, 29.16 vs. 42.82%, respectively; P=4×10⁻⁸). Furthermore, results from receiver operating characteristic curve analysis identified a significant area under the curve of 0.706, with a sensitivity and a specificity of 77.8 and 58.1%, respectively, between cancer tissues and paired adjacent non-tumor tissues. Furthermore, the methylation of IL10 CGI was significantly associated with patients' age at diagnosis (r=−0.201; P=0.03). Subgroup analyses demonstrated that the association between IL10 CGI hypomethylation and the risk of GC was specific for patients with low differentiation (P=1×10⁻⁷) and Borrmann types III+IV (P=1×10⁻⁷). In addition, IL10 CGI hypomethylation was significantly associated with the risk of GC for patients without smoking history (P=3×10⁻⁷) or a family history of cancer (P=2×10⁻⁷). The results from Kaplan-Meier survival analysis demonstrated that IL10 CGI hypomethylation was associated with a significantly shorter overall survival of patients with GC (P=0.041). Similar results were identified for patients with GC who did not have smoking history (P=0.037) or a family history of cancer (P=0.049). The results from this study demonstrated that IL10 CGI hypomethylation may be considered as a potential biomarker for the diagnosis and prognosis of patients with GC in the Chinese population.

Prognostic value of low microRNA-34a expression in human gastrointestinal cancer: a systematic review and meta-analysis

Background

Mounting evidence shows that microRNA-34a (miR-34a) is involved in cancer prognosis. Therefore, we summarize the predictive role of miR-34a for survival in patients with gastrointestinal cancers (GICs).

Methods

All eligible studies were found by searching PubMed, Web of Science and EMBASE, and survival results were extracted. Then, the hazard ratio (HR) with the corresponding 95% confidence interval (CI) was calculated to evaluate the prognostic role of miR-34a in GICs. The association between miR-34a expression and clinicopathological characteristics was estimated by odds ratios (ORs) and 95% CIs.

Results

A total of 20 studies were included in this meta-analysis. For overall survival (OS), lower miR-34a expression could probably predict poorer outcome in GICs, with a pooled HR of 1.86 (95% CI: 1.52–2.28, P < 0.01). For disease-free survival (DFS), progression-free survival (PFS), and recurrence-free survival (RFS), lower miR-34a expression was related to worse DFS/PFS/RFS with a pooled HR of 1.86 (95% CI: 1.31–2.63, P  <  0.01). A significant relation of differentiation/TNM stage/lymphatic metastasis and the expression level of miR-34a was identified.

Conclusion

This meta-analysis revealed that lower miR-34a expression is significantly connected with worse OS and DFS/PFS/RFS in GIC patients. In addition, the miR-34a expression level is relatively lower in patients with lymph node metastasis than in patients without lymph node metastasis, and decreased miR-34a expression levels are linked to poor tumour differentiation and late TNM stage. MiR-34a may become a new factor for the prognosis prediction and progression of GICs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07751-y.

Organoid models of gastrointestinal cancers in basic and translational research

Cancer is a major public health problem worldwide. Gastrointestinal cancers account for approximately one-third of the total global cancer incidence and mortality. Historically, the mechanisms of tumour initiation and progression in the gastrointestinal tract have been studied using cancer cell lines in vitro and animal models. Traditional cell culture methods are associated with a strong selection of aberrant genomic variants that no longer reflect the original tumours in terms of their (metastatic) behaviour or response to therapy. Organoid technology has emerged as a powerful alternative method for culturing gastrointestinal tumours and the corresponding normal tissues in a manner that preserves their genetic, phenotypic and behavioural traits. Importantly, accumulating evidence suggests that organoid cultures have great value in predicting the outcome of therapy in individual patients. Herein, we review the current literature on organoid models of the most common gastrointestinal cancers, including colorectal cancer, gastric cancer, oesophageal cancer, liver cancer and pancreatic cancer, and their value in modelling tumour initiation, metastatic progression and therapy response. We also explore the limitations of current organoid models and discuss how they could be improved to maximally benefit basic and translational research in the future, especially in the fields of drug discovery and personalized medicine.

The disconnect in hepatitis screening: participation rates, awareness of infection status, and treatment-seeking behavior

Background

Over 325 million people in the world are infected with hepatitis B or C virus. Chronic hepatitis is responsible for 78% of cases of hepatocellular carcinoma and an estimated 1.3 million preventable deaths a year. As “silent killers”, liver diseases are often asymptomatic and go undiagnosed until their terminal stage. Knowledge of infection status via screening is thus a vital part of preventing spread and seeking early treatment. Recently there has been a worldwide push to eliminate hepatitis. The objective of this study is to assess hepatitis B and C self-reported awareness of infection status vs correct awareness (compared to blood test results) and follow-up rates in Taiwan to inform global health promotion efforts that utilize screening interventions to prevent chronic liver diseases.

Methods

De-identified data from a Liver Foundation’s nationwide community-outreach free blood screening programs was utilized, including 50 909 participants’ data from 74 sites with a questionnaire (demographics, screening history, hepatitis awareness, monitoring behavior) and blood test results. Chi square tests were applied using R programing to examine the impacts of demographic variables on infection prevalence, awareness, and behavior relating to hepatitis.

Results

Among all participants, 41.1% indicated having had a hepatitis screening, of which only 60.8% knew their results. Around 69.7% and 66.5% self-reported awareness of their hepatitis B and C status respectively; 12.8% and 26.4% of individuals who tested positive for HBsAg and Anti-HCV respectively incorrectly thought they were not infected. Of those who self-reported awareness of their positive infection, 43.4% and 26.6% did not follow up with a health care professional for monitoring or treatment; the top reasons were “no symptoms”, “too busy”, and “don’t know where to follow up”. Rural populations showed higher infection prevalence but lower screening rates and self-reported awareness.

Conclusions

Intervention programs must address the substantial number of people that do not recall if they were screened or do not know the results of a screening. Discrepancies between self-reported awareness, correct awareness, and follow-up and disparities across demographic groups deserve further scrutiny. Global hepatitis eradication initiatives should reconsider how screening, test results, and education are presented in order to improve awareness and prevent chronic infection that could develop into life-threatening liver diseases.