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Background and objective: Two decades ago, an international initiative (GEMINI) was launched in a high-risk, low-resource region in Northeast Iran, aiming to investigate incidence, etiology, early detection, and treatment of esophageal squamous cell carcinoma (ESCC). An earlier report from this area, highlighted poor ESCC survival rates, with a 5-year survival probability of 3.3% and the median survival time of 7 months. Our study assesses whether ESCC survival has improved since the implementation of the GEMINI initiative in this region. Material and methods: 490 adult patients with histologically-confirmed ESCC were recruited from the Atrak clinic, Golestan, Iran, between 2007 and 2018. At recruitment, information on demographics and various exposures were collected. Active (telephone surveys) and passive (linkage to Golestan population-based cancer and death registries) follow-up methods were used to determine patients' vital status though March 2019. Survival estimates were obtained by Kaplan-Meier method and Cox proportional hazards regression models. Results: Over the study period 340 deaths were recorded. Five-year ESCC survival probability was 23% (95% Confidence Interval: 19% to 28%), and the median survival time was 19 months. Five-year survival probability was higher among individuals who were younger (35% in <60-year-olds vs. 12% for >70-year-olds, p<0.001), educated (34% vs. 21% for no formal education, p = 0.027), never used opium (28% vs. 15%, p = 0.0016), and received cancer treatment (37% vs. 4%, p<0.001). In the adjusted models, a higher hazard of death was associated with older age [HR for each 10-year increase = 1.36 (95% CI = 1.22 to 1.51)], Turkman ethnicity [HR = 1.35 (95%CI: 1.07 to 1.70)], opium use [HR = 1.53 (95%CI: 1.20 to 1.94)],and receiving no cancer treatment [HR = 5.81 (95%CI: 3.97 to 8.52)]. Conclusion: Over the last two decades, ESCC survival in this population has significantly improved, highlighting the potential of enhancing healthcare infrastructure and ensuring access to affordable medical care in resource-limited, high-risk regions. Older age at diagnosis, Turkman ethnicity, opium use, and untreated cases (indicative of advanced disease at diagnosis) were identified as the main ESCC prognostic factors in this population. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is the second most common cancer in Malawi. Risk factors for this cancer in Malawi are poorly understood. Poor oral health has previously been linked to increased ESCC risk in other high‐incidence regions, including parts of Eastern and Southern Africa. We assessed the relationship between oral health and ESCC risk in a sex, age and location frequency‐matched case–control study based at two hospitals in Lilongwe, Malawi from 2017 to 2020. Trained interviewers used a structured questionnaire and direct observation to collect data on demographics; behaviors; oral hygiene habits; the sum of decayed, missing or filled teeth (DMFT score); oral mucosa status; lip depigmentation and dental fluorosis via a visual scale. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CI), adjusted for known and suspected ESCC risk factors. During the study period, 300 cases and 300 controls were enrolled. Subjects in the highest tertile of DMFT score (≥7) had an increased risk of ESCC with an adjusted OR of 1.96 (95% CI: 1.16–3.36) compared to those with a DMFT score of 0. Severe dental fluorosis was associated with a statistically nonsignificant increased risk of ESCC (adjusted OR = 2.24, 95% CI: 0.97–5.49) compared to individuals with no fluorosis. Associations with oral mucosa status, lip depigmentation and toothbrushing method and frequency were mostly null or uncertain. Poor oral health, indicated by a higher DMFT score, was associated with increased ESCC risk in Malawi. Dental fluorosis is another possible risk factor in this population, but further evaluation is necessary to clarify any effects of fluorosis on ESCC risk. [ABSTRACT FROM AUTHOR]

Background Studying carcinogens in tobacco and nontobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer. Methods The Golestan Cohort Study has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma. For this nested study, the cases comprised of all incident cases by January 1, 2018; controls were matched to the case by age, sex, residence, time in cohort, and tobacco use. We measured urinary concentrations of 33 exposure biomarkers of nicotine, polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for associations between the 90th vs the 10th percentiles of the biomarker concentrations and incident esophageal squamous cell carcinoma. Results Among individuals who did not currently use tobacco (148 cases and 163 controls), 2 acrolein metabolites, 2 acrylonitrile metabolites, 1 propylene oxide metabolite, and one 1,3-butadiene metabolite were significantly associated with incident esophageal squamous cell carcinoma (adjusted odds ratios between 1.8 and 4.3). Among tobacco users (57 cases and 63 controls), metabolites of 2 other volatile organic compounds (styrene and xylene) were associated with esophageal squamous cell carcinoma (OR = 6.2 and 9.0, respectively). In tobacco users, 2 tobacco-specific nitrosamines (NNN and N' -Nitrosoanatabine) were also associated with esophageal squamous cell carcinoma. Suggestive associations were seen with some polycyclic aromatic hydrocarbons (especially 2-hydroxynaphthalene) in nonusers of tobacco products and other tobacco-specific nitrosamines in tobacco users. Conclusion These novel associations based on individual-level data and samples collected many years before cancer diagnosis, from a population without occupational exposure, have important public health implications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Outdoor air pollution is a known lung carcinogen, but research investigating the association between particulate matter (PM) and gastrointestinal (GI) cancers is limited. OBJECTIVES: We sought to review the epidemiologic literature on outdoor PM and GI cancers and to put the body of studies into context regarding potential for bias and overall strength of evidence. METHODS: We conducted a systematic review and meta-analysis of epidemiologic studies that evaluated the association of fine PM [PM with an aerodynamic diameter of [less than or equal to]2.5 [micro]m (P[M.sub.2.5])] and P[M.sub.10] (aerodynamic diameter < 10 pm) with GI cancer incidence or mortality in adults. We searched five databases for original research published from 1980 to 2021 in English and summarized findings for studies employing a quantitative estimate of exposure overall and by specific GI cancer subtypes. We evaluated the risk of bias of individual studies and the overall quality and strength of the evidence according to the Navigation Guide methodology, which is tailored for environmental health research. RESULTS: Twenty studies met inclusion criteria and included participants from 14 countries; nearly all were of cohort design. All studies identified positive associations between PM exposure and risk of at least one GI cancer, although in 3 studies these relationships were not statistically significant. Three of 5 studies estimated associations with P[M.sub.10] and satisfied inclusion criteria for meta-analysis, but each assessed a different GI cancer and were therefore excluded. In the random-effects meta-analysis of 13 studies, P[M.sub.2.5] exposure was associated with an increased risk of GI cancer overall [risk ratio (RR) = 1.12; 95% CI: 1.01, 1.24]. The most robust associations were observed for liver cancer (RR = 1.31; 95% CI: 1.07, 1.56) and colorectal cancer (RR = 1.35; 95% CI: 1.08, 1.62), for which all studies identified an increased risk. We rated most studies with 'probably low' risk of bias and the overall body of evidence as 'moderate' quality with 'limited' evidence for this association. We based this determination on the generally positive, but inconsistently statistically significant, effect estimates reported across a small number of studies. CONCLUSION: We concluded there is some evidence of associations between P[M.sub.2.5] and GI cancers, with the strongest evidence for liver and colorectal cancers. Although there is biologic plausibility for these relationships, studies of any one cancer site were few and there remain only a small number overall. Studies in geographic areas with high GI cancer burden, evaluation of the impact of different PM exposure assessment approaches on observed associations, and investigation of cancer subtypes and specific chemical components of PM are important areas of interest for future research. https://doi.org/10.1289/EHP9620, Introduction Gastrointestinal (GI) cancers are a major cause of cancer burden and cancer death. Worldwide, there were an estimated 4.8 million new cases of GI cancers and 3.4 million GI [...]