埃塞俄比亚奥罗米亚地区阿尔西-巴勒区食管癌病例对照研究中的人类生物监测多种霉菌毒素暴露评估

食管癌（EC）是一种预后较差的恶性肿瘤，五年生存率低于20%。它是全球发病率第九的癌症，也是癌症相关死亡的第六大原因。研究发现，EC的发病率在不同地区存在显著差异，提示环境和生活方式因素以及遗传因素在疾病发病中都扮演着重要角色。在本研究中，我们在埃塞俄比亚奥罗米亚地区阿尔西-巴勒区进行了一项病例对照研究，调查该地区EC发病率高，两大已知风险因素——酒精和烟草使用极少的情况下的霉菌毒素暴露情况。通过液相色谱-串联质谱（LC-MS/MS）分析血浆样本，评估了39种霉菌毒素及其代谢产物的内源性暴露，样本来自166例EC病例和166名匹配健康对照，二者具有相似的饮食来源。采用结构化问卷收集人口统计学和生活方式数据。利用主成分分析（PCA）和机器学习模型识别与EC相关的最相关的人口、生活习惯和（共）暴露霉菌毒素变量。多变量二元逻辑回归分析用于评估EC风险。所有血浆样本中都检测到霉菌毒素的暴露，EC病例样本中检测到10种不同的霉菌毒素，而健康对照样本中检测到6种不同的霉菌毒素。所有病例和对照样本中均检测到奥克特菌素A（Ochratoxin A），而145例（87.3%）病例和71例（42.8%）对照的血浆中检测到 tenuazonic acid。多变量逻辑回归分析显示，暴露于 tenuazonic acid（调整比值比（AOR）= 1.88 [95% CI：1.68-2.11]）及多种霉菌毒素（AOR=2.54 [95% CI：2.10-3.07]）与EC呈正相关。所有样本中至少暴露于一种霉菌毒素，病例暴露的霉菌毒素种类明显多于对照。暴露于 tenuazonic acid 和多种霉菌毒素与研究人群EC发生风险增加相关。尽管本研究未评估 aflatoxin B1-赖氨酸（Aflatoxin B1-lysine）以及 sphinganine 与 sphingosine 之比（作为 fumonisin 暴露的效应生物标志物），但我们的结果强调了将霉菌毒素共暴露的作用作为暴露组分进行特征化的必要性，并将其纳入风险评估，因为目前的霉菌毒素安全水平未考虑霉菌毒素共暴露的加和或协同作用。此外，为获得关于霉菌毒素暴露在疾病发生和发展中的作用的确切结论，应考虑在埃塞俄比亚EC高发区采用前瞻性研究设计，进行定期采样。

Esophageal cancer (EC) is a malignancy with a poor prognosis and a five-year survival rate of less than 20%. It is the ninth most frequent cancer globally and the sixth leading cause of cancer-related deaths. The incidence of EC has been found to vary significantly by geography, indicating the importance of environmental and lifestyle factors along with genetic factors in the onset of the disease. In this work, we investigated mycotoxin exposure in a case-control study from the Arsi-Bale districts of Oromia regional state in Ethiopia, where there is a high incidence of EC while alcohol and tobacco use - two established risk factors for EC - are very rare.Internal exposure to 39 mycotoxins and metabolites was assessed by liquid chromatography-tandem mass spectrometry in plasma samples of EC cases (n = 166) and location-matched healthy controls (n = 166) who shared similar dietary sources. Demographic and lifestyle data were collected using structured questionnaires. Principal Component Analysis and machine learning models were used to identify the most relevant demographic, lifestyle, and mycotoxin (co-)exposure variables associated with EC. Multivariate binary logistic regression analysis was used to assess EC risk.Evidence of mycotoxin exposure was observed in all plasma samples, with 10 different mycotoxins being detected in samples from EC cases, while only 6 different mycotoxins were detected in samples from healthy controls. Ochratoxin A was detected in plasma from all cases and controls, while tenuazonic acid was detected in plasma of 145 (87.3%) cases and 71 (42.8%) controls. Using multivariable logistic regression analysis, exposure to tenuazonic acid (AOR = 1.88 [95% CI: 1.68-2.11]) and to multiple mycotoxins (AOR = 2.54 [95% CI: 2.10-3.07]) were positively associated with EC.All cases and controls were exposed to at least one mycotoxin. Cases were exposed to a statistically significantly higher number of mycotoxins than controls. Exposure to tenuazonic acid and to multiple mycotoxins were associated with increased risk of EC in the study population. Although aflatoxin B1-lysine and the ratio of sphinganine to sphingosine (as a biomarker of effect to fumonisin exposure) were not assessed in this study, our result emphasizes the need to characterize the effect of mycotoxin co-exposure as part of the exposome and include it in risk assessment, since the current mycotoxin safety levels do not consider the additive or synergistic effects of mycotoxin co-exposure. Moreover, a prospective study design with regular sampling should be considered in this high incidence area of EC in Ethiopia to obtain conclusive results on the role of mycotoxin exposure in the onset and development of the disease.