Esophageal cancer genetics in South Africa

The CXCR4 might be a potential biomarker for esophageal squamous cell carcinoma: A meta-analysis

OBJECTIVE

To evaluate the relationship between CXCL12/CXCR4 and the progress, prognosis of esophageal squamous cell carcinoma (ESCC), providing evidence for potential early diagnosis, clinical treatment, prognosis evaluation, and therapeutic target of ESCC.

METHODS

Databases of PubMed, the Cochrane Library, Embase, and Web of Science were searched for the relationship between CXCL12/CXCR4 and clinicopathological characteristics and survival time of ESCC. Stata16.0 software was used to conduct meta-analysis.

RESULTS

A total of 10 studies involving 1216 cases of patients with ESCC were included in our study. The results indicated that high-level expression of CXCR4 was significantly correlated with tumor differentiation [OR = 0.69, 95% confidence interval (CI): (0.50, 0.97)], tumor infiltration [OR = 0.39, 95% CI: (0.25, 0.61)], lymph node metastasis [OR = 0.36, 95% CI: (0.21, 0.61)], clinical stage [OR = 0.33, 95% CI: (0.24, 0.45)] of ESCC. The expression of CXCR4 was also significantly correlated with OS [HR = 2.00, 95% CI: (1.63, 2.45)] and disease-free survival [HR = 1.76, 95% CI: (1.44, 2.15)] in patients of ESCC after surgical resection. No significant relationship was observed between the expression of CXCL12 and the clinicopathological characteristics of ESCC.

CONCLUSION

CXCR4 might be a potential biomarker for the progress and prognosis evaluation, and therapeutic target for ESCC.

A Genomic Analysis of Esophageal Squamous Cell Carcinoma in Eastern Africa

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) comprises 90% of all esophageal cancer cases globally and is the most common histology in low-resource settings. Eastern Africa has a disproportionately high incidence of ESCC.

METHODS

We describe the genomic profiles of 61 ESCC cases from Tanzania and compare them to profiles from an existing cohort of ESCC cases from Malawi. We also provide a comparison to ESCC tumors in The Cancer Genome Atlas (TCGA).

RESULTS

We observed substantial transcriptional overlap with other squamous histologies via comparison with TCGA PanCan dataset. DNA analysis revealed known mutational patterns, both genome-wide as well as in genes known to be commonly mutated in ESCC. TP53 mutations were the most common somatic mutation in tumors from both Tanzania and Malawi but were detected at lower frequencies than previously reported in ESCC cases from other settings. In a combined analysis, two unique transcriptional clusters were identified: a proliferative/epithelial cluster and an invasive/migrative/mesenchymal cluster. Mutational signature analysis of the Tanzanian cohort revealed common signatures associated with aging and cytidine deaminase activity (APOBEC) and an absence of signature 29, which was previously reported in the Malawi cohort.

CONCLUSIONS

This study defines the molecular characteristics of ESCC in Tanzania, and enriches the Eastern African dataset, with findings of overall similarities but also some heterogeneity across two unique sites.

IMPACT

Despite a high burden of ESCC in Eastern Africa, investigations into the genomics in this region are nascent. This represents the largest comprehensive genomic analysis ESCC from sub-Saharan Africa to date.

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.

Esophageal and Head and Neck Cancer Patients Attending Ocean Road Cancer Institute in Tanzania from 2019 to 2021: An Observational Study

BACKGROUND

Cancer in Africa is an emerging public health problem that needs urgent preventive measures, particularly in workplaces where exposure to carcinogens may occur. In Tanzania, the incidence rate of cancer and mortality rates due to cancers are increasing, with approximately 50,000 new cases each year. This is estimated to double by 2030.

METHODS

Our hospital-based cross-sectional study describes the characteristics of newly diagnosed patients with head and neck or esophageal cancer from the Ocean Road Cancer Institute (ORCI), Tanzania. We used an ORCI electronic system to extract secondary data for these patients.

RESULTS

According to the cancer registration, there were 611 head and neck and 975 esophageal cancers recorded in 2019-2021. Two-thirds of these cancer patients were male. About 25% of the cancer patients used tobacco and alcohol, and over 50% were involved in agriculture.

CONCLUSION

Descriptions of 1586 head and neck cancer patients and esophageal cancer patients enrolled in a cancer hospital in Tanzania are given. The information may be important for designing future studies of these cancers and may be of value in the development of cancer prevention measures.

An Inquiry into Cancer-Related Knowledge, Understanding, and Health-Seeking Behavior of Men Living in South Africa

In 2018, we conducted a survey among a convenience sample of men (n = 205) living in a resource-poor, semi-urban community in South Africa. We aimed to describe what they know about cancer by asking questions about cancer-related knowledge and understanding, and health-seeking behavior. We also investigated possible relationships between the variables. We used a researcher-administered questionnaire to collect the data and descriptive statistics and quantitative content analyses for the analysis. Chi-square was used to examine the relationships. The mean age of the sample was 35 years, and 49.8% (n = 102) attended 11 or 12 years of school. One-third (32.7%; n = 67) indicated they knew what cancer was, but only 28.8% (n = 59) gave an explanation: "very dangerous/a killer/worse than HIV" were the most common explanations. Only 24.9% (n = 51) were able to identify a possible warning sign, and "feeling very sick" was the most common. However, more than 60% considered six of the seven warning signs of cancer as serious. When suspecting they might have cancer, most (77%; n = 159) indicated they would tell the preferred person within 1 week, while 5.9% (n = 12) would tell "nobody." Although the majority (52.2%; n = 107) felt their partners and families motivated them to seek healthcare when sick, 28.3% (n = 58) needed permission to consult a professional. Educating the community about cancer in a culturally sensitive manner, irrespective of their educational level and perceived knowledge of cancer, could improve knowledge and understanding and lead to seeking healthcare timely.

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.

Cancer Omics in Africa: Present and Prospects

During the last century, cancer biology has been arguably one of the most investigated research fields. To gain deeper insight into cancer mechanisms, scientists have been attempting to integrate multi omics data in cancer research. Cancer genomics, transcriptomics, metabolomics, proteomics, and metagenomics are the main multi omics strategies used currently in the diagnosis, prognosis, treatment, and biomarker discovery in cancer. In this review, we describe the use of different multi omics strategies in cancer research in the African continent and discuss the main challenges facing the implementation of these approaches in African countries such as the lack of training programs in bioinformatics in general and omics strategies in particular and suggest paths to address deficiencies. As a way forward, we advocate for the establishment of an "African Cancer Genomics Consortium" to promote intracontinental collaborative projects and enhance engagement in research activities that address indigenous aspects for cancer precision medicine.