This paper describes results from a systematic review and a series of meta-analyses of nearly three decades worth of epidemiologic research on the relationship between non-Hodgkin lymphoma (NHL) and occupational exposure to agricultural pesticide active ingredients and chemical groups. Estimates of associations of NHL with 21 pesticide chemical groups and 80 active ingredients were extracted from 44 papers, all of which reported results from analyses of studies conducted in high-income countries. Random effects meta-analyses showed that phenoxy herbicides, carbamate insecticides, organophosphorus insecticides and the active ingredient lindane, an organochlorine insecticide, were positively associated with NHL. In a handful of papers, associations between pesticides and NHL subtypes were reported; B cell lymphoma was positively associated with phenoxy herbicides and the organophosphorus herbicide glyphosate. Diffuse large B-cell lymphoma was positively associated with phenoxy herbicide exposure. Despite compelling evidence that NHL is associated with certain chemicals, this review indicates the need for investigations of a larger variety of pesticides in more geographic areas, especially in low- and middle-income countries, which, despite producing a large portion of the world’s agriculture, were missing in the literature that were reviewed.

Introduction: The purpose of this study is to report prevalence and determinants of use of smokeless tobacco in a representative sample of men and women from Sweden, where Swedish snus sales are legal, and from 17 other European countries, where sales of smokeless tobacco are restricted. Methods: In 2010, a face-to-face survey including information on current smokeless tobacco use was conducted in a representative sample of around 1000 individuals aged ≥15 years per country in Albania, Austria, Bulgaria, Czech Republic, Croatia, England, Finland, France, Greece, Hungary, Ireland, Italy, Latvia, Poland, Portugal, Romania, Spain and Sweden. Results: In Sweden, the overall prevalence of smokeless tobacco use was 12.3% (20.7% in men, 3.5% in women). The corresponding estimate for other European countries combined was 1.1% (1.2% in men, 1.1% in women). Compared with never smokers, former smokers in Sweden were significantly more likely to use smokeless tobacco (odds ratio, OR: 2.67), whereas no difference in use was observed in other countries (OR: 1.04). Use of smokeless tobacco was similar among current smokers in Sweden (OR: 1.96) and in other countries (OR: 2.40) when contrasted to never smokers. In Sweden there were no differences in the number of cigarettes/day between smokers who also use smokeless tobacco (13.3 cigarettes/day) and exclusive cigarette smokers (12.9 cigarettes/day; P = 0.785). Conclusions: Excluding Sweden, current oral tobacco use was not commonly reported in the European countries surveyed and was similarly rare both in men and in women. In Sweden, however, use of smokeless tobacco was about 10-fold higher than the rest of Europe and more prevalent in men than in women.

AGRICOH is a recently formed consortium of agricultural cohort studies involving 22 cohorts from nine countries in five continents: South Africa (1), Canada (3), Costa Rica (2), USA (6), Republic of Korea (1), New Zealand (2), Denmark (1), France (3) and Norway (3). The aim of AGRICOH, initiated by the US National Cancer Institute (NCI) and coordinated by the International Agency for Research on Cancer (IARC), is to promote and sustain collaboration and pooling of data to investigate the association between a wide range of agricultural exposures and a wide range of health outcomes, with a particular focus on associations that cannot easily be addressed in individual studies because of rare exposures (e.g., use of infrequently applied chemicals) or relatively rare outcomes (e.g., certain types of cancer, neurologic and auto-immune diseases). To facilitate future projects the need for data harmonization of selected variables is required and is underway. Altogether, AGRICOH provides excellent opportunities for studying cancer, respiratory, neurologic, and auto-immune diseases as well as reproductive and allergic disorders, injuries and overall mortality in association with a wide array of exposures, prominent among these the application of pesticides.

Qat (Catha edulis) chewing is reported to induce lesions in the buccal mucosa, irritation of the esophagus, and esophageal reflux. Case series suggest a possible etiological role in oral and esophageal cancers. This pilot study aimed to generate preliminary estimates of the magnitude and direction of the association between qat use and esophageal cancer (EC) risk and to inform the logistics required to conduct a multi-center case–control study. Between May 2012 and May 2013, 73 EC cases (including 12 gastro-esophageal junction cases) and 133 controls matched individually on sex, age, and residence were enrolled at two endoscopy clinics and a cancer treatment hospital in Addis Ababa. A face-to-face structured questionnaire was administered. Qat use was defined as ever having chewed qat once a week or more frequently for at least one year. Odds ratios were calculated using conditional logistic regression. Only 8% of cases resided in Addis Ababa. Qat use was more frequent in cases (36%) than in controls (26%). A 2-fold elevation in EC risk was observed in ever qat chewers compared with never users in unadjusted conditional logistic regression (OR = 2.12; 95% CI = 0.94, 4.74), an association that disappeared after adjusting for differences in tobacco use, consumption of alcohol and green vegetables, education level, and religion (OR = 0.95; 0.22, 4.22). Among never tobacco users, however, a non-significant increase in EC risk was suggested in ever qat users also after adjustment. Increases in EC risk were observed with ever tobacco use, alcohol consumption, low consumption of green vegetables, a salty diet, illiteracy, and among Muslims; the four latter associations were significant. This pilot study generated EC risk estimates in association with a habit practiced by millions of people and never before studied in a case–control design. Results must be interpreted cautiously in light of possible selection bias, with some demographics such as education level and religion differing between cases and controls. A large case–control study with enrolment of EC cases and carefully matched controls at health facilities from high-risk areas in the countryside, where the majority of cases occur, is needed to further investigate the association between qat use and EC.

Background: It is difficult to determine the prevalence/incidence of EC without an established functional national cancer registry, which helps to demarcate the population at-risk and monitor cancer trends over time. The review of medical records can help to identify areas in a country with high number of diagnosed EC cases and help set public health priorities. Aim: To describe EC hospital case series during a period of 4 years at the main cancer treatment center in Ethiopia and two hospitals in the EC high-risk zones in the Oromia region, concentrating on residents of Oromia region and to offer recommendations for public health officials. Methods: All EC malignancy data from the period 2013-2016 were collected by reviewing patient charts at the selected hospitals: Tikur Anbessa Teaching hospital (TATH) in Addis Ababa, Adama General and Medical Teaching Hospital (AGMTH) and Adama Referral and Medical Teaching Hospital (ARMTH). Cases with insufficient residence information and residents of other regions were excluded from the summary. The number of EC cases is presented by age, sex and site as well as method of diagnosis. Data were expressed as percentages (%). Statistical analysis was done using SPSS 20 software. Results: Over the study period, a total of 669 EC cases who resided in Oromia region were identified in the selected hospitals out of 2211 registered in the referral surgical departments of hospitals in the study, with insignificant difference by sex. A total of 457 (68%) were residents from high risk Arsi/Bale zones and the rest 212 (32%) from other zones of the region. The mean age at diagnosis was 52.4 years with the majority of cases in the age range 45-69 years. A total of 34 (5%) EC cases were younger at diagnosis (15-29 years). A total of 258 (38.5%) cases were identified at TATH, 305 (46%) from AGHMT/ARHMT and 106 (16%) cases from both TATH/AGHMT. Data were gathered from patient charts at endoscopy departments 227 (34%), endoscopy and pathology departments 246 (37%) and all other sources (ie surgical department) 196 (29%). Most patients complained dysphagia for solids 664 (99%) and weight loss 352 (53%). Cases were histopathology proven (256, 38%), identified through endoscopy investigation (385, 58%) or radiology (28, 4%). Squamous cell carcinoma was the predominant histology type with 160 cases (62.5%) of those histologically proven. Among the total of 420 cases whose risk factor history was recorded, 401 (97%) had a previous history of digestive disease, 49% reported hot beverage consumption and 34% persistent heart burn. Conclusion: Two thirds of EC incident cases came from Arsi and Bale zones with decreasing trends over the period considered. Such trends warrant in depth investigation for possible reasons and future study to investigate local based risk factors associated with the disease.

Ethiopia lies in the high-risk corridor of esophageal squamous cell carcinoma in East Africa, where individuals with this malignancy often do not report established risk factors, suggesting unidentified etiologies. Here, we report the prevalence of mucosal human papillomavirus (HPV) and of Helicobacter pylori (H. pylori) detection in endoscopy-obtained esophageal and gastroesophageal junction biopsies and in oral cell specimens taken at the time of esophageal cancer diagnosis in a case–control study in Addis Ababa, Ethiopia. DNA extraction was performed from fresh frozen tissue and oral cell pellets obtained with saline solution gargling subsequently fixed with ethanol. Mucosal HPV and H. pylori DNA was detected using highly sensitive assays that combine multiplex polymerase chain reaction and bead-based Luminex technology. The proportions of specimens testing positive were expressed as percentages, with binomial 95% confidence intervals. Agreement of results between tissue biopsy and oral cell specimens was estimated using the kappa statistic. Comparison of study participants’ characteristics by test results was done using the Pearson chi-square test. HPV DNA was detected in 1 of 62 tumor specimens (2, 95% confidence interval (CI): 0–9%), corresponding to HPV16 type. HPV DNA was detected in the oral cavity of 7 cases (11, 95% CI: 5–22%) and 4 of 56 matched healthy controls (7, 95% CI: 2–17%), with multiple HPV types detected. Detection of H. pylori DNA was 55% (95% CI: 42–68%), and 20 of 34 H. pylori-positive specimens (59, 95% CI: 41–75%) were positive for the cagA gene. Agreement of detection rates between tissue and oral cells in cases was poor for HPV and for H. pylori. The prevalence of mucosal-type HPV was very low, whereas H. pylori was more commonly detected, with a high proportion testing positive for the pro-inflammatory gene cagA. These novel findings remain to be replicated in larger studies and with the addition of serological determinations to better understand their biological significance in the context of esophageal and gastroesophageal junction cancers.