食管癌高危人群营养干预试验的实践与再认识

PRACTICE AND RE-RECOGNITION ON TRIALS OFNUTRITIONAL INTERVENTION CONDUCTED IN HIGH-RISK POPULATION OF CANCER OF THE ESOPHAGUS

从本世纪８０年代开始，在中国华北食管癌高发地带——太行山区，相继开展了一系列食管癌人群营养干预试验研究。所用药物大多是维生素、微量元素之类不等。作者以自身经历和所见所闻，简要报道这些事实。这些研究人群，少者３００多人，大者３万多人；观察时间，短则１年，长则１０年。总的来讲，这些研究，设计合理、观察严密，然而结果多数令人失望。失望之余，催人深思。这些试验为什么没有得到预期效果？或者说效果不理想，诸多营养素为什么没有显示出防癌作用呢？作者从时间效应；组织、器官及人群特异性；营养素的负效应；以及其它致癌物的继续暴露等方面进行了分析和讨论。并对人类癌症，特别是对食管癌的营养干预，提出了不同看法、希望和建议。

Since the 1980s of this century,a series of studies on the experiments with nutritional inter-vention have been successively conducted in population groups of high-incidence areas of cancer of the esopha-gus along the Tai Hang Mountains in North China. The drugs used included predominantly vitamins,trace ele-ments and others. Brief facts are now reported in this paper with what the authors themselves have exper-ineced and what they have heard of.Of the population groups experimented on,smaller ones was composed of300 people while larger ones could be made up of 30,000 people. As to the duration of observation it might beas short as one year but as long as 10 years. Generally speaking,in spite of the reasonability in the planning ofthe experiments and carefulness in their observations,the results found had been disappointing,Nevertheless,the disappointments had provided us with much food for thought why had these experiments not yieldedthe resulted anticipated,and why had no anticancer role been played by a multiplicity of nutrients? In this pa-per,analyses and discussions were made in terms of time effect,specificity of tissues and body organs and pop- ulation groups involved,the negative effects of the nutrients as well as the continuous exposure to other car-cinogens. Besides,suggestions hopes and different points of view on the nutritional intervention in human can-cers,especially cancer of the esophagus,were presented.