BACKGROUND: Hepatopancreatobiliary (HPB) cancers encompassing malignancies of the liver, pancreas, gall bladder, and bile ducts pose a significant health burden in Africa. While the association of certain occupational carcinogens in cancer is well established globally, their potential role in HPB cancers remains understudied, especially in an African context.
OBJECTIVE: This systematic review delves into the association between occupational carcinogens and HPB cancer in Africa. It examines the current state of research on occupational carcinogens and HPB cancers in Africa, identifying key challenges and knowledge gaps.
METHODS: This systematic review examined publications (published between 01 January 2012 and 31 May 2023) that highlight occupational carcinogens and HBP cancers in Africa. The search was conducted on electronic databases namely PubMed, Web of Science, and Africa Wide Information.
RESULTS: Due to the lack of information on the association between occupational carcinogens and HPB cancers in Africa, as a result of the paucity of published studies, only four articles were included in this study. Hepatocellular carcinoma (HCC) was the predominant cancer associated with the occupational carcinogen, aflatoxin. Agricultural workers, especially those involved in the production and processing of maize and peanuts, appear to be the most exposed to aflatoxin.
CONCLUSIONS: Despite the sample size limitations due to the paucity of research studies on occupational carcinogens and HPB cancers in Africa, this study provides a reasonable tool for subsequent epidemiological studies. There is a need for more research on the association of occupational carcinogens and HPB cancers in Africa, especially with the growing industrialization.

Occupational exposure to carcinogens of increasing cancer risk have been extensively suggested. A robust assessment of these evidence is needed to guide public policy and health care. We aimed to classify the strength of evidence for associations of 13 occupational carcinogens (OCs) and risk of cancers. We searched PubMed and Web of Science up to November 2022 to identify potentially relevant studies. We graded the evidence into convincing, highly suggestive, suggestive, weak, or not significant according to a standardized classification based on: random-effects p value, number of cancer cases, 95% confidence interval of largest study, heterogeneity between studies, 95% prediction interval, small study effect, excess significance bias and sensitivity analyses with credibility ceilings. The quality of meta-analysis was evaluated by AMSTAR 2. Forty-eight articles yielded 79 meta-analyses were included in current umbrella review. Evidence of associations were convincing (class I) or highly suggeastive (class II) for asbestos exposure and increasing risk of lung cancer among smokers (RR = 8.79, 95%CI: 5.81-13.25 for cohort studies and OR = 8.68, 95%CI: 5.68-13.24 for case-control studies), asbestos exposure and increasing risk of mesothelioma (RR = 4.61, 95%CI: 2.57-8.26), and formaldehyde exposure and increasing risk of sinonasal cancer (RR = 1.68, 95%CI: 1.38-2.05). Fifteen associations were supported by suggestive evidence (class III). In summary, the current umbrella review found strong associations between: asbestos exposure and increasing risk of lung cancer among smokers; asbestos exposure and increasing risk of mesothelioma; and formaldehyde exposure and higher risk of sinonasal cancer. Other associations might be genuine, but substantial uncertainty remains.

BACKGROUND: Our aimed to conduct a meta-analysis of cohort studies on risk of genitourinary (GU) cancers in workers exposed to welding fumes (WF).
METHODS: We performed a systematic review of studies published on Pubmed, Scopus and Embase following PRISMA criteria. Two researchers selected cohort studies on WF exposure. From 2582 articles, 7 non-overlapping studies were included. Quality of studies was scored according to CASP. We run a random effects meta-analysis to calculate the relative risk (RR) and 95% confidence intervals (CI) of GU cancer, overall and stratified by cancer, country, and quality score.
RESULTS: We included seven studies reporting results on GU cancers, including prostate, bladder and kidney cancer (PC, BC, and KC). The RR was 1.19 (95% CI = 1.07-1.32, 16 risk estimates) for GU cancer; 1.13 (95% CI = 0.90-1.42, 4 risk estimates) for PC; 1.26 (95% CI = 0.98-1.60, 7 risk estimates) for BC and 1.28 (95% CI = 1.12-1.47, 5 risk estimates) for KC. Heterogeneity was present in all meta-analyses (p < 0.001). The increased risk was more pronounced in North American than in European studies (respectively, OR = 1.35, 95% CI = 1.18-1.55; OR = 1.13, 95% CI = 1.01-1.27 p heterogeneity = 0.03). There was no heterogeneity according to quality score (p = 0.4). Data were insufficient to investigate associations by industry or welding type. Publication bias for each cancer was excluded.
CONCLUSIONS: This meta-analysis suggests increased risk of KC and BC, but not of PC, in workers exposed to WF. Confounding by other occupational and non-occupational risk factors could not be excluded. Data were not adequate to address the risk of specific exposure circumstances.

Social habits such as smoking and drinking alcohol are well-known causative agents for oral and oropharyngeal squamous cell carcinoma (OSCC/OPSCC). Human papillomavirus (HPV) is a known causative agent for OPSCC. However, we often encounter patients with no identifiable risk factors. There is growing evidence of the role of occupational carcinogens in the pathogenesis of oral cancer. The aim of this study therefore was to identify any occupational carcinogens linked to oral cancer. We carried out a systematic review of the literature using PubMed, EMBASE, and Medline, along with a retrospective review of patients treated in a regional unit over 25 years. Occupations were classified based on the UK Standard of Classification 2020. Data analysis was completed using the chi-squared test. A total of 17 papers met the inclusion criteria for review. In our retrospective study a total of 874 patients were identified of whom 31% were blue-collar workers, 32.8% were white-collar workers, 20.2% were unemployed/housewives, and 16% workers in other occupations. The majority of blue-collar workers were in the construction industry and had maximum exposure to hydrocarbons and exhaust fumes. The aetiology of oral and oropharyngeal SCC is multifactorial and there is no consensus on the role of occupational carcinogens. We showcase our patient cohort and discuss the occupational exposures that appear to make them susceptible to OSCC and OPSCC. Further multicentre studies are required to enable us to understand fully the pathogenesis of oral cancer and help us to inform relevant organisations, the aim being to reduce the incidence of occupation-related cancer.

Background: Occupational cancers can be avoided by removing dangerous chemicals from the workplace or limiting occupational exposure. Approximately, 10 major risk factors account for 85% of all occupational cancers. This scoping review study aimed to determine the most important chemical carcinogens related to 5 known occupational cancers. Methods: In this scoping review, we followed Arksey and O\'Malley\'s 5-step framework. Four databases (PubMed, Web of Science, Google Scholar, Scopus) were systematically reviewed for relevant published papers from January 2000 to September 2021. Studies were included in this scoping review, which examined the effect of carcinogenic (definite and probable) chemical exposures on 5 known occupational cancers (lung, bladder, laryngeal, leukemia, and liver). We reported the types of occupational carcinogens, the geographical diversity of studies, extraction of relative risks (RRs), hazard ratios (HRs), or odds ratios (ORs), and identified gaps in the existing literature. Results: The highest number of studies was related to lung cancer (LC) (n = 26), bladder cancer (BC) (n = 11), laryngeal cancer (LaC) (n = 8), leukemia (LeC) (n = 3), and primary liver cancer (PLC) (n = 2), respectively. Most studies were performed in France and Canada (n = 8), Germany (n = 4), Finland (n = 3), Netherlands (n = 2), and Finland (n = 2), respectively. Furthermore, the most common occupational chemical carcinogens associated with the 5 known occupational cancers were asbestos, benzene, crystalline silica, polycyclic aromatic hydrocarbons (PAH), and diesel motor exhausts (DME). Conclusion: Although the attributable risk of occupational cancers in developing countries is much higher, a small proportion of studies were performed in these countries.