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©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
Systematic review and meta-analysis of esophageal cancer in Africa: Epidemiology, risk factors, management and outcomes
Akwi W Asombang, Nathaniel Chishinga, Alick Nkhoma, Jackson Chipaila, Bright Nsokolo, Martha Manda-Mapalo, Joao Filipe G Montiero, Lewis Banda, Kulwinder S Dua
Akwi W Asombang, Division of Gastroenterology/Hepatology, Warren Alpert Medical School of Brown University, Providence, RI 02903, United States
Nathaniel Chishinga, Department for HIV Elimination, Fulton County Government, Atlanta, GA 30303, United States
Alick Nkhoma, Department of Gastroenterology, Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Staffordshire ST4 6QG, United Kingdom
Jackson Chipaila, Department of Surgery, University Teaching Hospital-Adult Hospital, Lusaka 10101, Zambia
Bright Nsokolo, Department of Medicine, Levy Mwanawasa University Teaching Hospital, Tropical Gastroenterology and Nutrition Group (TROPGAN), Lusaka 10101, Zambia
Martha Manda-Mapalo, Department of Medicine, The University of New Mexico, Albuquerque, NM 87106, United States
Joao Filipe G Montiero, Department of Medicine, Brown University, Providence, RI 02903, United States
Lewis Banda, Hematology/Oncology, Cancer Disease Hospital, Lusaka 10101, Zambia
Kulwinder S Dua, Department of Medicine and Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, United States
Author contributions: Asombang AW, Chishinga N, Banda L, Dua KS designed and conceptualized the review; Asombang AW, Chishinga N, Nkhoma A, Chipaila J, Nsokolo B, Manda-Mapalo M, Montiero JFG were involved in data acquisition and analysis; all authors contributed to data interpretation, drafting the initial manuscript, reviewing and approving the final manuscript as submitted.
Conflict-of-interest statement: All the authors declare that they have no competing interests.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Akwi W Asombang, FAAP, FACP, FACG, FASGE MD, MPH Assistant Professor of Medicine, Interventional Gastroenterologist, Clinician Educator, Division of Gastroenterology/Hepatology, Warren Alpert Medical School of Brown University, POB 240, 110 Lockwood Street, Providence, RI 02903, United States. akwi_asombang@brown.edu
Telephone: +1-401-4445031
Received: April 15, 2019
Peer-review started: April 15, 2019
First decision: May 16, 2019
Revised: July 5, 2019
Accepted: July 19, 2019
Article in press: July 19, 2019
Published online: August 21, 2019
BACKGROUND
Esophageal cancer (EC) is associated with a poor prognosis, particularly so in Africa where an alarmingly high mortality to incidence ratio prevails for this disease.
AIM
To provide further understanding of EC in the context of the unique cultural and genetic diversity, and socio-economic challenges faced on the African continent.
METHODS
We performed a systematic review of studies from Africa to obtain data on epidemiology, risk factors, management and outcomes of EC. A non-systematic review was used to obtain incidence data from the International Agency for Research on Cancer, and the Cancer in Sub-Saharan reports. We searched EMBASE, PubMed, Web of Science, and Cochrane Central from inception to March 2019 and reviewed the list of articles retrieved. Random effects meta-analyses were used to assess heterogeneity between studies and to obtain odds ratio (OR) of the associations between EC and risk factors; and incidence rate ratios for EC between sexes with their respective 95% confidence intervals (CI).
RESULTS
The incidence of EC is higher in males than females, except in North Africa where it is similar for both sexes. The highest age-standardized rate is from Malawi (30.3 and 19.4 cases/year/100000 population for males and females, respectively) followed by Kenya (28.7 cases/year/100000 population for both sexes). The incidence of EC rises sharply after the age of 40 years and reaches a peak at 75 years old. Meta-analysis shows a strong association with tobacco (OR 3.15, 95%CI: 2.83-3.50). There was significant heterogeneity between studies on alcohol consumption (OR 2.28, 95%CI: 1.94-2.65) and on low socioeconomic status (OR 139, 95%CI: 1.25-1.54) as risk factors, but these could also contribute to increasing the incidence of EC. The best treatment outcomes were with esophagectomy with survival rates of 76.6% at 3 years, and chemo-radiotherapy with an overall combined survival time of 267.50 d.
CONCLUSION
Africa has high incidence and mortality rates of EC, with preventable and non-modifiable risk factors. Men in this setting are at increased risk due to their higher prevalence of tobacco and alcohol consumption. Management requires a multidisciplinary approach, and survival is significantly improved in the setting of esophagectomy and chemoradiation therapy.
Core tip: Esophageal cancer is an important cause of cancer related deaths world-wide, but particularly in Africa where mortality rates due to this condition have been found to be higher. We systematically reviewed the literature on esophageal cancer in Africa and present our findings on the incidence, risk factors, management strategies, resultant outcomes and overall survival.
