流行病学调查提示黄曲霉毒素、伏马菌素、亚硝胺的联合作用及维生素C缺乏可能在食管癌前病变过程中发挥了重要作用，但仍缺少人群病例对照研究资料和实验室的直接证据。本研究选择江苏淮安食管癌高发区2017-2018年食管癌前病变新筛查患者100例，以同地区、同性别、年龄相差2岁以内匹配健康人100例，应用双份饭法备份研究对象连续3天的膳食，采集血样，通过检测三种致癌物的内外暴露水平和维生素C的营养状况，分析三种致癌物的联合作用及维生素C缺乏与食管癌前病变的关系。同时结合人群研究结果，用黄曲霉毒素、伏马菌素、亚硝胺处理人类食管正常上皮细胞并用维生素C干预，观察三种致癌物的联合作用对人类正常食管上皮细胞周期、凋亡和相关基因表达的影响及维生素C的干预效果，寻找三种致癌物的联合作用和维生素C缺乏与食管癌前病变关系更直接的证据，探讨其在食管癌发生发展中的意义及其机理，为食管癌一级预防措施的制定提供科学依据。

A large number of studies have shown that lack of vitamin C and the combined effects of aflatoxin, fumonisins and nitrosamine were related with the process of precancerous esophageal cancer, but it still lacks a comprehensive system of population-based case-control studies and laboratory direct evidence. This case-control study based on the evaluation of the nutritional status of populations who were different stage of esophageal cancer, and selected 100 cases of new precancerous cases in Jiangsu Huai'an which was the high esophageal cancer area from 2017 to 2018. According to the same region, the same sex, age difference less than two years, we match 100 normal cases with controls, collect the blood samples, and detect the internal and external exposure levels of three carcinogen. The vitamin c in serum will also be detected, and the diet of cases will be investigated for three days by duplicate portion method. For the laboratory studies, we treat human normal esophageal epithelial cells with aflatoxin, fumonisins and nitrosamine, then intervene with vitamin c , and observe the cytotoxicity, cell cycle, cell apoptosis, related genes expression and effect of vitamin C so that it could verify the results of population studies, find direct evidences about lack of vitamin C and the combined effects of aflatoxin, fumonisins and nitrosamine in the process of precancerous esophageal cancer. All the results will provide a scientific basis for making the precautionary measures of esophageal cancer.