Africa's Oesophageal Cancer Corridor: Geographic Variations in Incidence Correlate with Certain Micronutrient Deficiencies

Establishing a cancer registry and baseline data for Nyandarua County, Kenya: A step towards establishing a central cancer registry

Cancer is a major global public health issue, causing a significant number of premature deaths worldwide. In 2020, the World Health Organization reported that more than 19 million individuals were diagnosed with cancer, and over 10 million lost their lives to the disease. Predictions indicate that cancer-related deaths will exceed 30 million by 2030, with around 75 % occurring in low- and middle-income countries (LMICs) like Kenya. Various factors contribute to this concerning trend, including aging populations, a high prevalence of cancer risk factors, socioeconomic disparities resulting in limited healthcare access, and deficiencies in healthcare systems within LMICs. This study focused on Nyandarua County, Kenya, which lacks a dedicated cancer registry. Without comprehensive incidence data, the county faces challenges in developing targeted programs for cancer prevention, management, and control. The main objective of this investigation was to establish a cancer registry specific to Nyandarua County, capable of continuously gathering accurate cancer data, patient treatment follow-ups and disease outcomes. A demographic survey was conducted to determine the frequency of all-cause and specific cancers among patients who attended selected health facilities between 2013 and 2020. Data were collected from existing hospital records in three main hospitals in the county. A total of 1373 cases were recorded, with 54.9 % of patients being female. North Kinangop Catholic Hospital accounted for the largest number of patients (62 %), followed by JM Kariuki County Memorial Hospital (35 %), while Engineer Hospital contributed the remaining 3 %. The top five cancer sites observed in Nyandarua County were esophagus (16.8 %), cervix uteri (13.4 %), stomach (10.6 %), breast (8.8 %), and prostate (8.6 %). Our findings provide valuable insights into the prevalence and distribution of different types of cancer in the region. With the establishment of this cancer registry, Nyandarua County is now among the pioneering counties in Kenya. It is crucial for the county government to undertake the responsibility of continuously updating the registry to draw inferences regarding cancer prevalence in the region to enhance patients follow up and survival.

Keratin 17 and Collagen type 1 genes: Esophageal cancer molecular marker discovery and evaluation

One hundred eighty pairs of tissues of esophageal squamous cell carcinoma (ESCC) were tested by the transcriptome sequencing in order to explore etiology factors. The chi-square test and correlation analysis demonstrated that the relative expression levels of keratin 17 (KRT17) and collagen type I α1 chain (COL1A1) were significantly higher in EC with diabetes. Expression of KRT17 was correlated with blood glucose (r = 0.204, p = 0.001) and tumor size (r = -0.177, p = 0.038) in patients. COL1A1 correlated with age (r = -0.170, p = 0.029) and blood glucose levels (r = 0.190, p = 0.015). Experimental results of qRT-PCR: KRT17 and COL1A1 genes were highly expressed in ESCC (p < 0.05). When the two genes were used as a combination test, the positive detection rate of EC was 90.6%, and the ROC curve had greater power. The KRT17 and COL1A1 genes had the potential to be biomarkers for the diagnosis of ESCC.

Zinc Deficiency as a General Feature of Cancer: a Review of the Literature

Trace elements are minerals that are present in very low concentrations in the human body and yet are crucial for a wide range of physiological functions. Zinc, the second most abundant trace element, is obtained primarily from the diet. After being taken up in the intestine, zinc is distributed to various target organs, where it plays key roles in processes such as immunity, protein folding, apoptosis, and antioxidant activity. Given the important role of zinc in a wide range of enzymatic reactions and physiological processes, zinc deficiency has been identified in a variety of diseases, notably cancer. In recent years, multiple meta-analyses and reviews looking at zinc levels in individual cancer types have been published, as have a plethora of primary studies demonstrating a link between low zinc levels and specific types of cancer. In this review, we summarize recent evidence implicating low zinc concentrations in serum or tissues as a characteristic in a wide range of cancers. We also discuss preliminary findings indicating that zinc level measurement could ultimately become a useful clinical tool for cancer diagnosis and predicting outcomes in patients with cancer. Finally, we suggest future directions for further elucidating the role of zinc deficiency in cancer development and progression.

Age-period-cohort analysis of incidence, mortality and disability-adjusted life years of esophageal cancer in global, regional and national regions from 1990 to 2019

OBJECTIVE

In view of the high incidence and mortality of esophageal cancer, the latest statistical data on the disease burden of esophageal cancer can provide strategies for cancer screening, early detection and treatment, and help to rationally allocate health resources. This study provides an analysis of the global disease burden and risk factors of esophageal cancer from 1990 to 2019.

METHODS

Using the 2019 Global Burden of Disease, Injury and Risk Factor (GBD) data, we present the incidence, mortality and disability-adjusted life years (DALY) of esophageal cancer in 21 regions and 204 countries and different sociodemographic index (SDI) regions from 1990 to 2019. The age-period-cohort model was used to estimate the age, period, and cohort trend of esophageal cancer in different SDI regions. The estimated proportion of DALY attributable to each risk factor from 1990 to 2019.

RESULTS

From 1990 to 2019, the number of new cases of esophageal cancer, the number of deaths and DALY increased by 67.07%, 55.97% and 42.13%, respectively, but age standardized incidence rate (ASIR), age standardized mortality rate (ASMR) and age standardized DALY rate (ASDR) decreased by 19.28%, 25.32% and 88.22%, respectively. Overall, the results of the age-period-cohort model showed that the incidence, mortality, and DALY rates in countries and regions with higher SDI levels showed a downward trend over time and with the passage of time. Conversely, there were no significant changes in incidence and mortality in countries and regions with low SDI levels. In the past 30 years, the incidence and death of esophageal cancer in the world has gradually changed to people over 80 years old, but the population aged 60-79 still accounts for the largest proportion. The global DALY in esophageal cancer is mainly attributable to smoking, followed by alcohol consumption and occupational exposure.

CONCLUSIONS

Although ASIR, ASMR and ASDR have decreased significantly, esophageal cancer is still the main factor causing the disease burden worldwide. Public health administrators in low SDI and low-middle SDI countries are high-risk areas for esophageal cancer, and preventive control measures should be implemented to raise awareness, screening, and treatment of esophageal cancer in these areas. Tobacco and alcohol control and reduction of occupational hazards are key steps in reducing the burden of esophageal cancer.

Spatiotemporal Distribution, Time to Treatment Outcome Clustering and Determinants of Esophageal Cancer in Ethiopia, a Scoping Study

INTRODUCTION

Esophageal cancer was the eighth and sixth leading cause of morbidity of all cancers in the world, and the 15th and 12th in Ethiopia, respectively. There is a lack of comprehensive data regarding Ethiopia's esophageal cancer hotspot, treatment outcome clustering, and other factors.

OBJECTIVE

This scoping review was designed to understand the extent and type of existing evidence regarding spatiotemporal distribution, time to treatment outcome clustering, and determinants of esophageal cancer in Ethiopia up to March 28, 2023.

METHODS

Three-step search strategies were employed for the scoping review from March 15 to 28, 2023. Targeted databases included PubMed/Medline, PubMed Central (PMC), Google Scholar, Hinari, and Cochrane for published studies and different websites for unpublished studies for evidence synthesis. Data were extracted using the Joanna Briggs Institute (JBI) manual format.

RESULTS

Our final analysis comprised 17 (16 quantitative and 1 qualitative) studies. Three studies attempted to depict the country's temporal distribution, whereas 12 studies showed the spatial distribution of esophageal cancer by proportion. The regional state of Oromia recorded a high percentage of cases. Numerous risk factors linked to the tumor have been identified in 8 investigations. Similarly, 5 studies went into detail regarding the likelihood of survival and the factors that contribute to malignancy, while 2 studies covered the results of disease-related treatments.

CONCLUSIONS

The substantial body of data that underpins this finding supports the fact that esophageal cancer has several risk factors and that its prevalence varies greatly across the country and among regions. Surgery, radiotherapy, or chemotherapy helped the patient live longer. However, no research has investigated which treatment is best for boosting patient survival and survival clustering. Therefore, research with robust models for regional distribution, clustering of time to treatment outcomes, and drivers of esophageal cancer will be needed.

Environmental and life-style risk factors for esophageal squamous cell carcinoma in Africa: a systematic review and meta-analysis

BACKGROUND

The African Esophageal Squamous Cell Carcinoma (ESCC) corridor, which spans from Ethiopia down to South Africa, is an esophageal cancer hotspot. Disproportionately high incidence and mortality rates of esophageal cancer have been reported from this region. The aim of this study was to systematically assess the evidence on environmental and life-style risk factors associated with ESCC in African populations.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and carried out a comprehensive search of all African published studies up to March 2023 using PubMed, Embase, Scopus, and African Index Medicus databases.

RESULTS

We identified 45 studies with measures of association [odds ratio (OR), relative risk (RR), and 95% confidence intervals (95%CI)], which reported on several environmental and lifestyle risk factors for ESCC in Africa. We performed a meta-analysis on 38 studies investigating tobacco, alcohol use, combined tobacco and alcohol use, polycyclic aromatic hydrocarbon exposure, hot food and beverages consumption (which served as a proxy for esophageal injury through exposure to high temperature), and poor oral health. We found significant associations between all the risk factors and ESCC development. Analysis of fruit and vegetable consumption showed a protective effect. Using population attributable fraction (PAF) analysis, we calculated the proportion of ESCC attributable to tobacco (18%), alcohol use (12%), combined tobacco and alcohol use (18%), polycyclic aromatic hydrocarbon exposure (12%), hot food and beverages intake (16%), poor oral health (37%), and fruit and vegetable consumption (-12%).

CONCLUSIONS

Tobacco smoking and alcohol consumption were the most studied risk factors overall. Areas where there is an emerging body of evidence include hot food and beverages and oral health. Concurrently, new avenues of research are also emerging in PAH exposure, and diet as risk factors. Our results point to a multifactorial etiology of ESCC in African populations with further evidence on prevention potential.

Global trends in the burden of esophageal cancer, 1990-2019: results from the Global Burden of Disease Study 2019

Background

Esophageal cancer is one of the leading causes of cancer death worldwide. A deeper understanding of the trends in annual incidence, mortality, and disability-adjusted life-years (DALYs) of esophageal cancer is critical for management and prevention. In this study, we report on the disease burden of esophageal cancer in 204 countries and territories between 1990 and 2019 by age, sex, and sociodemographic index (SDI).

Methods

Data on incidence, mortality, and DALYs were extracted from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. The estimated numbers and age-standardized rates for esophageal cancer in 2019 are presented in this paper, as well as trends from 1990 to 2019. All estimates are presented as counts and age-standardized rates per 100,000 population, with 95% uncertainty intervals (UIs) for each estimate.

Results

In 2019, nearly 535,000 (95% UI: 467,000-595,000) new cases of esophageal cancer occurred globally. Esophageal cancer was responsible for more than 498,000 (95% UI: 438,000-551,000) deaths and 11.7 million (95% UI: 10.4-12.9 million) DALYs. Worldwide age-standardized rates of esophageal cancer, including incidence, deaths, and DALYs, have declined since 1990. However, the trends differ across countries and territories. Notably, there was a nonlinear but generally inverse correlation between age-standardized DALY rates and SDI. Higher age-standardized incidence and death rates were observed in males compared to females, and both increased with age. Regarding risk factors, smoking, alcohol use, and high body-mass index were 3 predominant contributors to esophageal cancer DALYs in 2019 for both sexes worldwide.

Conclusions

This study found a global reduction in the esophageal cancer burden, but substantial heterogeneity remains across regions and countries. Hence, the identification of high-risk groups and the exploration of specific local strategies and primary prevention efforts are required.

Micro-climatic variations across Malawi have a greater influence on contamination of maize with aflatoxins than with fumonisins

This study reports levels of aflatoxin and fumonisin in maize samples (n = 1294) from all agroecological zones (AEZs) in Malawi. Most maize samples (> 75%) were contaminated with aflatoxins and 45% with fumonisins, which co-occurred in 38% of the samples. Total aflatoxins varied across the AEZs, according to mean annual temperature (P < 0.05) of the AEZs. Samples from the lower Shire AEZ (median = 20.8 µg/kg) had higher levels of aflatoxins (P < 0.05) than those from the other AEZs (median = 3.0 µg/kg). Additionally, the majority (75%) of the positive samples from the lower Shire AEZ had aflatoxin levels exceeding the EU regulatory limit (4 µg/kg), whereas 25%, 37%, and 39% of positive samples exceeded the threshold in the mid-elevation, Lake Shore and upper and middle Shire, and highlands AEZs, respectively. The lower Shire AEZ is characterised by higher mean temperatures throughout the year and low erratic rainfall. However, total fumonisins did not show significant variation across AEZs, but all positive samples exceeded 150 µg/kg, required for tolerable daily intake of 1.0 µg/kg body weight per day, established by the European Food Safety Authority Panel on Contaminants in the Food Chain. Therefore, results of this study suggest that contamination of maize with aflatoxin responds to micro-climate more than with fumonisins. In addition, the data will be useful to public health policy-makers and stakeholders to articulate and implement monitoring and mitigation programs.

Tracing global flows of bioactive compounds from farm to fork in Nutrient Balance Sheets can help guide intervention towards healthier food supplies

Adequate supplies of healthy foods available in each country are a necessary but not sufficient condition for adequate intake by each individual. This study provides complete Nutrient Balance Sheets that account for all plant-based and animal-sourced food flows from farm production through trade to non-food uses and waste in 173 countries from 1961 to 2018. We track 36 bioactive compounds in all farm commodities recorded by the Food and Agriculture Organization of the United Nations, accounting for nutrient-specific losses in processing and cooking as well as bioavailability. We compare supply to requirements given each country's age-sex distribution and find that the adequacy of food supplies has increased but often remains below total needs, with even faster rise in energy levels and lower density of some nutrients per calorie. We use this nutrient accounting to show how gaps could be filled, either from food production and trade or from selected biofortification, fortification and supplementation scenarios for nutrients of concern such as vitamin A, iron and zinc.

Dietary Risk Assessment and Consumer Awareness of Mycotoxins among Household Consumers of Cereals, Nuts and Legumes in North-Central Nigeria

This study characterized the health risks due to the consumption of mycotoxin-contaminated foods and assessed the consumer awareness level of mycotoxins in households in two north-central Nigerian states during the harvest and storage seasons of 2018. Twenty-six mycotoxins and 121 other microbial and plant metabolites were quantified by LC-MS/MS in 250 samples of cereals, nuts and legumes. Aflatoxins were detected in all food types (cowpea, maize, peanut and sorghum) except in millet. Aflatoxin B1 was the most prevalent mycotoxin in peanut (64%) and rice (57%), while fumonisin B1 occurred most in maize (93%) and beauvericin in sorghum (71%). The total aflatoxin concentration was highest in peanut (max: 8422 µg/kg; mean: 1281 µg/kg) and rice (max: 955 µg/kg; mean: 94 µg/kg), whereas the totals of the B-type fumonisins and citrinin were highest in maize (max: 68,204 µg/kg; mean: 2988 µg/kg) and sorghum (max: 1335 µg/kg; mean: 186 µg/kg), respectively. Citrinin levels also reached 51,195 µg/kg (mean: 2343 µg/kg) in maize. Aflatoxin and citrinin concentrations in maize were significantly (p < 0.05) higher during storage than at harvest. The estimated chronic exposures to aflatoxins, citrinin and fumonisins were high, resulting in as much as 247 new liver cancer cases/year/100,000 population and risks of nephrotoxicity and esophageal cancer, respectively. Children who consumed the foods were the most vulnerable. Mycotoxin co-occurrence was evident, which could increase the health risk of the outcomes. Awareness of mycotoxin issues was generally low among the households.

What to Do for Increasing Cancer Burden on the African Continent? Accelerating Public Health Diagnostics Innovation for Prevention and Early Intervention on Cancers

No other place illustrates the increasing burden of cancer than in Africa and in particular, sub-Saharan Africa. Many of the individuals to be diagnosed with cancer will be in low-resource settings in the future due to, for example, an increase in populations and aging, and high co-morbidity with infections with viruses such as human immunodeficiency virus (HIV) and human papillomavirus (HPV), as well as the presence of infectious agents linked to cancer development. Due to lack of prevention and diagnostic innovation, patients present with advanced cancers, leading to poor survival and increased mortality. HIV infection-associated cancers such as B cell lymphomas, Kaposi's sarcoma, and HPV-associated cancers such as cervical cancer are particularly noteworthy in this context. Recent reports show that a host of other cancers are also associated with viral infection and these include lung, oral cavity, esophageal, and pharyngeal, hepatocellular carcinoma, and anal and vulvar cancers. This article examines the ways in which diagnostic innovation empowered by integrative biology and informed by public health priorities can improve cancer prevention or early intervention in Africa and beyond. In addition, I argue that because diagnostic biomarkers can often overlap with novel therapeutic targets, diagnostics research and development can have broader value for and impact on medical innovation.

Processing and Analysis of Tissue Samples from Esophageal Cancer Patients in an African Setting

Although infectious diseases continue to present a major health care problem in Africa, the incidence of cancer is increasing rapidly on the African continent and this merits an increased investment in cancer research in low to medium resource settings. Esophageal squamous cell carcinoma (ESCC) has a high incidence in Eastern and Southern Africa, with late clinical presentation and a very poor prognosis. There is limited research on the molecular pathology of this cancer in Africa, partly as a result of a lack of infrastructure for biobanking and sample processing in many African countries. The aim of this study was to establish a practical and robust workflow to collect, store, and process esophageal cancer samples such that both the tissue architecture and quality of the samples would be preserved and suitable for future genomic research. We developed a workflow that allows storage of fresh biopsy tissue in sterile Eppendorf tubes containing RNAlater, an efficient RNAse inhibitor. We collected 142 ESCC biopsy samples and showed that storage in RNAlater for up to 18 months did not alter tissue morphology, thus allowing histologic assessment by experienced pathologists and determination of tumor content in each biopsied sample. DNA and RNA extracted from tissue samples was assessed for purity, molecular size, and yield. The quantity and quality of nucleic acids obtained were suitable for genomic applications, and whole-exome sequencing of DNA from tumor tissues produced sequence data with a high proportion of both usable reads and correct base calling. We conclude that this workflow may be applicable to a wide range of malignancies for future genomic research in low-resource settings.

African genetic diversity and adaptation inform a precision medicine agenda

The deep evolutionary history of African populations, since the emergence of modern humans more than 300,000 years ago, has resulted in high genetic diversity and considerable population structure. Selected genetic variants have increased in frequency due to environmental adaptation, but recent exposures to novel pathogens and changes in lifestyle render some of them with properties leading to present health liabilities. The unique discoverability potential from African genomic studies promises invaluable contributions to understanding the genomic and molecular basis of health and disease. Globally, African populations are understudied, and precision medicine approaches are largely based on data from European and Asian-ancestry populations, which limits the transferability of findings to the continent of Africa. Africa needs innovative precision medicine solutions based on African data that use knowledge and implementation strategies aligned to its climatic, cultural, economic and genomic diversity.

Clinico-Pathological Findings and Spatial Distributions of Esophageal Cancer in Arsi Zone, Oromia, Central Ethiopia

PURPOSE

Arsi Zone is one of the esophageal cancer endemic areas and is reported to have a high incidence of esophageal cancer in Ethiopia. This study assessed clinicopathological patterns and spatial distributions of esophageal cancer in Arsi Zone, Oromia, Central Ethiopia.

METHODS

A cross-sectional study design was carried out by abstracting data of 403 patients treated from January 2015 to January 2019. Data were collected by using a structured data collection form and Geographical Positioning System software. The collected data were summarized in the form of tables, figures, means, and standard deviations. Statistical data analysis was done using SPSS software version 21.0 while geospatial analysis was conducted using the Arc-GIS 10.1 software.

RESULTS

The disease was prominent among individuals aged 50 to 59 years. The mean age of females and males was 52.2 (SD±10.41) and 56.94 (SD ±12.27) years respectively. The vast majority (98.3%) of cases had squamous cell carcinoma. Dysphagia with weight loss accounted for 87.6% of the presenting symptoms. A large proportion (42.9%) of patients had a tumor located at the lower thorax. The majority (62%) of patients were from the eastern and north-eastern parts of the Arsi zone.

CONCLUSION

Dysphagia with weight loss was the major symptom during the first visit. Squamous cell carcinoma was the predominant histopathological type. Eastern and the northeastern parts of the Zone are the most affected regions. Future studies should focus on the determinants of esophageal cancer and precise areas with high incidences by using the population and/or facility-based cancer registry systems.

Prognostic Role of Nodal Skip Metastasis in Thoracic Esophageal Squamous Cell Carcinoma: A Large-Scale Multicenter Study

BACKGROUND

Nodal-skip metastasis (NSM) is found in esophageal squamous cell carcinoma (ESCC), but its prognostic role is controversial. This study aimed to investigate the prognostic value of NSM for thoracic ESCC patients.

METHODS

Categorization of NSM was according to the N groupings of Japan Esophagus Society (JES) staging system, which is dependent on tumor location. Using the Kaplan-Meier method and Cox-regression analysis, this study retrospectively analyzed the overall survival (OS) for 2325 ESCC patients after radical esophagectomy at three high-volume esophageal cancer centers. Predictive models also were constructed.

RESULTS

The overall NSM rate was 20% (229/1141): 37.4% in the in upper, 12.9% in the middle, and 22.2% in the lower thoracic ESCC. The patients with NSM always had a better prognosis than those without NSM. Furthermore, NSM was an independent prognostic factor for thoracic ESCC patients (hazard ratio [HR], 0.633; 95% confidence interval [CI], 0.499-0.803; P < 0.001). By integrating the prognostic values of NSM and N stage, the authors proposed the new N staging system. The categories defined by the new N staging system were more homogeneous in terms of OS than those defined by the current N system. Moreover, the new N system was shown to be an independent prognostic factor also for thoracic ESCC patients (HR, 1.607; 95% CI, 1.520-1.700; P < 0.001). Overall, the new N system had slightly better homogeneity, discriminatory ability, and monotonicity of gradient than the current N system.

CONCLUSIONS

This study emphasized the prognostic power of NSM and developed a modified node-staging system to improve the efficiency of the current International Union for Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) N staging system.

Dietary and Environmental Determinants of Oesophageal Cancer in Arsi Zone, Oromia, Central Ethiopia: A Case-Control Study

PURPOSE

Oesophageal cancer is ranked 5th of all types of malignancies in Ethiopia and highly prevalent in the Arsi Zone. However, no study was conducted to elucidate the dietary and environmental determinants of oesophageal cancer in the Arsi Zone.

METHODS

A matched case-control study was conducted from June 1, 2019, to June 30, 2020. A total of 104 cases and 208 controls were interviewed. Data were collected using food frequency questionnaires (structured questionnaires). Binary and multiple logistic regression analyses were conducted to check the association between independent and dependent variables. Adjusted odds ratios and the corresponding 95% confidence intervals were estimated for the strength of association. Statistical significance was declared at a P-value of <0.05.

RESULTS

In multivariable logistic regression, drinking very hot coffee (AOR=5.1,[95% CI: (1.95, 13.71), drinking large volume of coffee (AOR=4.9, [95% CI: (2.03, 12.17), very hot porridge (AOR= 3.1,[95% CI: (1.38,7.03) and eating porridge fast (AOR=7.0, [95% CI: (2.48, 20.14), low intake of dairy products (AOR=6.0, [95% CI: (2.29, 15.95), cooking food in sleeping room (AOR=3.7, [95% CI: (1.22, 11.39), exposure to x-ray (AOR=9.4,[95% CI: (3.94, 22.82), nonalcohol homemade drinks (AOR=5.4,[95% CI: (1.97, 15.14), use of chemical containers (AOR=3.4, [95% CI: (1.48, 8.23) were determinants of oesophageal cancer.

CONCLUSION

Coffee temperature, coffee drinking volume, porridge consumption temperature, porridge consumption speed, dairy products intake patterns, food cooking place, x-ray exposure, nonalcohol homemade drink, and use of chemical containers were independent determinants of the increased risk of oesophageal cancer in the study community.

Survival Status of Esophageal Cancer Patients and its Determinants in Ethiopia: A Facility Based Retrospective Cohort Study

Background

Globally, the incidence and mortality due to esophageal cancer are increasing, particularly in low- and middle-income countries. Cancer of the esophagus is the eighth in incidence and seventh in cancer mortality in Ethiopia. A few studies have shown an increasing burden, however, little is known about the survival pattern and its determinants among esophageal cancer patients in Ethiopia. Therefore, we assessed the survival pattern and its determinants among esophageal cancer patients.

Methods

We conducted a retrospective cohort study among 349 esophageal cancer patients who were diagnosed at or referred to Tikur Anbessa Specialized Hospital, Ethiopia from January 2010 to May 2017. Using an abstraction form, nurses who were working at the oncology department extracted the data from patient charts. To estimate and compare the probability of survival among covariate categories, we performed a Kaplan-Meier survival analysis with the log-rank test. To identify the prognostic determinants of survival, we performed a multivariable Cox proportional regression analysis.

Results

The median follow-up time was 32 months with interquartile range of 15 to 42. Overall, the median survival time after diagnosis with esophageal cancer was 4 months with one-, two- and three-year survival of 14.4, 6.3, and 2.4% respectively. In the multivariable Cox proportional hazards model, receiving chemotherapy [Adjusted Hazard Ratio (AHR)=0.36, 95%CI: 0.27-0.49], radiotherapy [AHR=0.38, 95%CI: 0.23-0.63] and surgery [AHR=0.70, 95%CI: 0.54-0.89] were statistically significant.

Conclusions

In Ethiopia, esophageal cancer patients have a very low one-, two- and three-year survival. Despite a very low overall survival, patients who received either chemotherapy, radiotherapy or surgery showed a better survival compared with those who did not receive any treatment. Hence, it is essential to improve the survival of patients with esophageal cancer through early detection and timely initiation of the available treatment options.

The Upper Digestive Tract Microbiome and Oesophageal Squamous Cell Carcinoma: Epidemiology, Pathogenesis, and Clinical Implications in Africa

The study of the microbiome has significantly contributed to our understanding of complex diseases including cancer, with a profound influence of the microbiota on clinical prognosis and the efficacy of cancer treatments. Oesophageal cancer is positioned amongst the most aggressive malignant diseases, resulting from a complex interaction between anthropometric, genetic, immune response, and environmental factors. Oesophageal squamous cell carcinoma (OSCC) is the most common type of oesophageal cancer and is a serious burden in Eastern Africa, in the area known as the African oesophageal cancer corridor (AOCC). OSCC is often diagnosed at a late stage, with patients already suffering from severe malnutrition and dehydration due to swallowing difficulties, leading to high mortality rates. So far, aetiological factors have been individually analysed with an inappropriate contextualisation. The upper digestive tract microbiome has been proposed to contribute to the onset and progression of OSCC but with limited understanding of the mechanisms behind this interaction. Data on African populations are limited, and the aetiology of AOCC is still poorly understood. This review discusses the current knowledge of the aetiology of OSCC in Africa, with special focus on the probable influence of the upper digestive tract microbiota.

Gender Differences in Oesophageal Squamous Cell Carcinoma in a South African Tertiary Hospital

(1) Oesophageal squamous cell carcinoma is common in Africa and has a male preponderance. The gender-based differences in clinical presentation and risk factor exposure are poorly studied in the African context. Our aim was to compare males and females with this disease. We analyzed the differences in clinical features and risk factor exposure between males and females with oesophageal cancer. (2) Data from patients presenting to a tertiary hospital in South Africa with oesophageal squamous cell carcinoma were analyzed. Data collected included patient demographics, clinical presentation, pathology and risk factor exposure. (3) Three hundred and sixty three patients were included in the study. The male to female ratio was 1.4:1. The mean age was 66 years for females and 61 years for males (p < 0.0001). A significantly larger percentage of males were underweight compared to females (60% vs. 32%, p < 0.001). There were no differences between the genders with regards to performance status, dysphagia grade and duration and tumor length, location and degree of differentiation. There were significant differences between risk factor exposure between the two genders. Smoking and alcohol consumption was an association in more than 70% of males but in less than 10% of females There was no difference survival. (4) Female patients with oesophageal squamous cell carcinoma (OSCC) are older and have a higher body mass index (BMI) than their male counterparts. Traditionally purported risk factors of smoking and alcohol consumption are infrequent associations with OSCC in female patients and other environmental risk factors may be more relevant in this gender.

Global trends in the incidence and mortality of esophageal cancer from 1990 to 2017

BACKGROUND

The incidence and mortality of esophageal cancer are high, with 5.90 new cases and 5.48 deaths per 100 000 people worldwide in 2017. The prognosis of esophageal cancer is poor, with an overall 5-year survival rate of less than 20%. Esophageal cancer in different geographical locations has different etiologies, and the incidence and mortality of esophageal cancer continue to rise in some regions.

METHODS

We collected incidence and mortality data by age and gender for 195 countries and territories from 1990 to 2017 in the Global Burden of Disease (GBD) database. And we used these data to calculate the estimated annual percentage change (EAPC) to quantify trends in morbidity and mortality. Then we analyzed the gender- and age-specific incidence and mortality in esophageal cancer to targeted high-risk populations. Finally, we analyzed the correlation between the age-standardized mortality rate (ASMR) and both the EAPC and social-demographic index (SDI), and we calculated the Pearson correlation coefficient.

RESULTS

We found that Malawi, East Asia, and high-middle SDI regions had the highest age-standardized incidence rate (ASIR) and ASMR, and the ASIR and ASMR in western Sub-Saharan Africa showed an upward trend. Our study also showed that the incidence and mortality in esophageal cancer were highest in men and in the 70+ years age group, and they presented a decreasing trend in most regions, but the 15-49 years age groups in Australasia, Caribbean, and Oceania and the 70+ years age group in High-Income North America, Oceania and high-SDI regions presented an increasing trend. There were significant negative associations between ASMR at baseline and EAPC and between ASMR and SDI in 2017.

CONCLUSION

By analyzing the global distribution of incidence and mortality in esophageal cancer, trends over time, and gender and age specificity, we can understand the heterogeneity of its global trends. This heterogeneity can help us to identify high-risk groupsand to provide clues for the exploration of the etiology and early prevention of the disease.

The state of cancer in Meru, Kenya: a retrospective study

Background: It is projected that by 2030, 70% of all cancer related deaths will occur in low-middle income countries. However, data on the state of cancer in most African countries is scanty. Cancer estimates for Kenya are based on the Nairobi and Eldoret cancer registries, leaving most parts of the country unrepresented. Lacking national coverage, these data do not accurately reflect Kenya’s cancer burden. The paucity of reliable data impedes formulation of effective cancer control strategies and cancer research prioritization. Here, we report the findings of a retrospective study of the cancer state in Meru County, Kenya. Methods: A retrospective analysis of patient files at Meru hospice was carried out. 2349 cancer cases seen at the Meru hospice between 2003 and 2018 were analyzed. Data abstracted from the records included patient age, gender and cancer type. The abstracted data was analyzed by descriptive statistics. Results: Our results indicate that cancer is almost evenly distributed across genders, with men accounting for 49% and women 51%. Stomach cancer rates are strikingly elevated and equal to those in countries with the highest stomach cancer rates globally – making it the commonest cancer in this region (14%). Among men, the most common cancers affect the prostate (18%), stomach (17%), esophagus (14%), head & neck (12%), liver (8%) and colorectum (5%). Among women, the commonest are cancers of the breast (22%), cervix (20%), stomach (11%), esophagus (8%), head & neck (6%) and liver (5%). Breast cancer occurs at a notably early age, with 20% of those affected aged below 40. Lung cancer rates are notably low in this region (1.3%) relative to world estimates. Conclusion: Cancer distribution in Meru is nearly even between sexes. Our analysis suggests that the Meru region is a stomach cancer hotspot and that it also experiences elevated esophageal cancer levels.

Source apportionment of micronutrients in the diets of Kilimanjaro,Tanzania and Counties of Western Kenya

Soil, water and food supply composition data have been combined to primarily estimate micronutrient intakes and subsequent risk of deficiencies in each of the regions studied by generating new data to supplement and update existing food balance sheets. These data capture environmental influences, such as soil chemistry and the drinking water sources to provide spatially resolved crop and drinking water composition data, where combined information is currently limited, to better inform intervention strategies to target micronutrient deficiencies. Approximately 1500 crop samples were analysed, representing 86 food items across 50 sites in Tanzania in 2013 and >230 sites in Western Kenya between 2014 and 2018. Samples were analysed by ICP-MS for 58 elements, with this paper focussing on calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), iodine (I), zinc (Zn) and molybdenum (Mo). In general, micronutrient supply from food groups was higher from Kilimanjaro,Tanzania than Counties in Western Kenya, albeit from a smaller sample. For both countries leafy vegetable and vegetable food groups consistently contained higher median micronutrient concentrations compared to other plant based food groups. Overall, calculated deficiency rates were <1% for Cu and Mo and close to or >90% for Ca, Zn and I in both countries. For Mg, a slightly lower risk of deficiency was calculated for Tanzania at 0 to 1% across simplified soil classifications and for female/males, compared to 3 to 20% for Kenya. A significant difference was observed for Se, where a 3 to 28% risk of deficiency was calculated for Tanzania compared to 93 to 100% in Kenya. Overall, 11 soil predictor variables, including pH and organic matter accounted for a small proportion of the variance in the elemental concentration of food. Tanzanian drinking water presented several opportunities for delivering greater than 10% of the estimated average requirement (EAR) for micronutrients. For example, 1 to 56% of the EAR for I and up to 10% for Se or 37% for Zn could be contributed via drinking water.

Temporal trends in food group availability and cancer incidence in Africa: an ecological analysis

OBJECTIVE

We evaluated the relationship between food availability, as the only dietary exposure data available across Africa, and age-standardised cancer incidence rates (ASR) in eighteen countries.

DESIGN

Ecological study.

SETTING

Availability of food groups and dietary energy was considered for five hypothetical time points: years of collection of ASR (T0) and 5, 10, 15 and 20 preceding years (T-5, T-10, T-15, T-20). Ecological correlations adjusted for human development index, smoking and obesity rates were calculated to evaluate the relationship between food availability and ASR of breast, prostate, colorectal, oesophageal, pancreatic, stomach and thyroid cancer.

RESULTS

Red meat was positively correlated with pancreatic cancer in men (T-20: r-20 = 0·61, P < 0·05), stomach cancer in women (T0: r0 = 0·58, P < 0·05), and colorectal cancer in men (T0: r0 = 0·53, P < 0·05) and women (T-20: r-20 = 0·58, P < 0·05). Animal products including meat, animal fats and higher animal-sourced energy supply tended to be positively correlated with breast, colorectal, pancreatic, stomach and thyroid cancer. Alcoholic beverages were positively correlated to oesophageal cancer in men (r0 = 0·69, P < 0·001) and women (r-20 = 0·72, P < 0·001).

CONCLUSIONS

The present analysis provides initial insights into the impact of alcoholic beverages, and increasing use of animal over plant products, on the incidence of specific cancers in Africa. The findings support the need for epidemiological studies to investigate the role of diet in cancer development in Africa.

Systematic Review of Genetic Factors in the Etiology of Esophageal Squamous Cell Carcinoma in African Populations

Background: Esophageal squamous cell carcinoma (ESCC), one of the most aggressive cancers, is endemic in Sub-Saharan Africa, constituting a major health burden. It has the most divergence in cancer incidence globally, with high prevalence reported in East Asia, Southern Europe, and in East and Southern Africa. Its etiology is multifactorial, with lifestyle, environmental, and genetic risk factors. Very little is known about the role of genetic factors in ESCC development and progression among African populations. The study aimed to systematically assess the evidence on genetic variants associated with ESCC in African populations.

Methods: We carried out a comprehensive search of all African published studies up to April 2019, using PubMed, Embase, Scopus, and African Index Medicus databases. Quality assessment and data extraction were carried out by two investigators. The strength of the associations was measured by odds ratios and 95% confidence intervals.

Results: Twenty-three genetic studies on ESCC in African populations were included in the systematic review. They were carried out on Black and admixed South African populations, as well as on Malawian, Sudanese, and Kenyan populations. Most studies were candidate gene studies and included DNA sequence variants in 58 different genes. Only one study carried out whole-exome sequencing of 59 ESCC patients. Sample sizes varied from 18 to 880 cases and 88 to 939 controls. Altogether, over 100 variants in 37 genes were part of 17 case-control genetic association studies to identify susceptibility loci for ESCC. In these studies, 25 variants in 20 genes were reported to have a statistically significant association. In addition, eight studies investigated changes in cancer tissues and identified somatic alterations in 17 genes and evidence of loss of heterozygosity, copy number variation, and microsatellite instability. Two genes were assessed for both genetic association and somatic mutation.

Conclusions: Comprehensive large-scale studies on the genetic basis of ESCC are still lacking in Africa. Sample sizes in existing studies are too small to draw definitive conclusions about ESCC etiology. Only a small number of African populations have been analyzed, and replication and validation studies are missing. The genetic etiology of ESCC in Africa is, therefore, still poorly defined.

Intra-household agreement of urinary elemental concentrations in Tanzania and Kenya: potential surrogates in case-control studies

Element deficiencies and excesses play important roles in non-communicable disease aetiology. When investigating their roles in epidemiologic studies without prospective designs, reverse-causality limits the utility of transient biomarkers in cases. This study aimed to investigate whether surrogate participants may provide viable proxies by assessing concentration correlations within households. We obtained spot urine samples from 245 Tanzanian and Kenyan adults (including 101 household pairs) to investigate intra-household correlations of urinary elements (As, Ba, Ca, Cd, Co, Cs, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, S, Se, Sr, Tl, V and Zn) and concentrations (also available for: Bi, Ce, Sb, Sn and U) relative to external population-levels and health-based values. Moderate-strong correlations were observed for As (r = 0.65), Cs (r = 0.67), Li (r = 0.56), Mo (r = 0.57), Se (r = 0.68) and Tl (r = 0.67). Remaining correlations were <0.41. Median Se concentrations in Tanzania (29 µg/L) and Kenya (24 µg/L) were low relative to 5738 Canadians (59 µg/L). Exceedances (of reference 95th percentiles) were observed for: Co, Mn, Mo, Ni and U. Compared to health-based values, exceedances were present for As, Co, Mo and Se but deficiencies were also present for Mo and Se. For well correlated elements, household members in East African settings provide feasible surrogate cases to investigate element deficiencies/excesses in relation to non-communicable diseases.

Managing Squamous Cell Esophageal Cancer

This article reviews the pathophysiology, risk factors, clinical presentation/diagnosis, and management of SCC.

The African Esophageal Cancer Consortium: A Call to Action

Esophageal cancer is the eighth most common cancer worldwide and the sixth most common cause of cancer-related death; however, worldwide incidence and mortality rates do not reflect the geographic variations in the occurrence of this disease. In recent years, increased attention has been focused on the high incidence of esophageal squamous cell carcinoma (ESCC) throughout the eastern corridor of Africa, extending from Ethiopia to South Africa. Nascent investigations are underway at a number of sites throughout the region in an effort to improve our understanding of the etiology behind the high incidence of ESCC in this region. In 2017, these sites established the African Esophageal Cancer Consortium. Here, we summarize the priorities of this newly established consortium: to implement coordinated multisite investigations into etiology and identify targets for primary prevention; to address the impact of the clinical burden of ESCC via capacity building and shared resources in treatment and palliative care; and to heighten awareness of ESCC among physicians, at-risk populations, policy makers, and funding agencies.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.

Research progress on the relationship between zinc deficiency, related microRNAs, and esophageal carcinoma

Esophageal cancer (EC) is a common malignant tumor of the gastrointestinal tract with a high incidence in China. Zinc (Zn) deficiency is a key risk factor for the occurrence and development of EC and affects progression by regulating microRNA (miRNA, miR) expression. In addition, the dysregulation of miRNAs is accompanied by the dysregulation of their target genes in EC. In this paper, we review the potential molecular mechanisms between Zn deficiency and EC with the aim of providing new strategies and methods for early diagnosis, targeted therapy, and prognostic evaluation.

International cancer seminars: a focus on esophageal squamous cell carcinoma

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.

Esophageal cancer in Kenya

Kenya belongs to a high incidence region known as Africa's esophageal cancer (EC) corridor. It has one of the highest incidence rates of EC worldwide, but research on EC in Kenya has gone highly unnoticed. EC in Kenya is unique in its high percentage of young cases (< 30 years of age). In this review, we show the current status of EC in the country. We mainly focus on significant risk factors such as alcohol drinking, genetic factors, malnutrition and hot food/drink. Future directions in the study and prevention of EC in Kenya are also discussed.

Global trends in esophageal cancer

BACKGROUND AND OBJECTIVES

Esophageal Cancer (EC) is a lethal malignancy with poor prognosis and significant variations in the incidence, mortality, and histopathology based on geographic regions. The aim of this study was to quantitatively analyze these variations to identify patterns and areas for further research.

METHODS

We utilized the GLOBOCAN 2012, and Cancer Incidence in five Continents, Volume X (CI5X) database to analyze variations in EC incidence and mortality.

RESULTS

We found the EC incidence and mortality is geographically varied with a particularly high burden in East Asia and Eastern/Southern Africa where esophageal squamous cell carcinoma (SCC) predominates over adenocarcinoma (AC). Interestingly, there is a dichotomy between the high incidence of esophageal SCC in East Africa and low incidence in West Africa. The global incidence and mortality from EC is expected to rise in the coming decades. Asia, and China in particular, will continue to be the areas most burdened by EC, while Africa is expected to surpass the incidence and mortality rates of Europe.

CONCLUSIONS

The global burden of EC is expected to rise in the coming years. Understanding the geographic, environmental, and genetic contributors to the development of EC will be essential in combating its prevalence.