曾有人提出,有一种胃癌的主要亚型(“肠型”)是在出生后十年内开始的一系列突变和细胞转变的最终结果。突变原可能是亚硝酸盐(来自食物或唾液)作用于天然存在的氮化合物,在上消化道形成的一种亚硝基化合物。在正常情况下,这些亚硝基化 It has been suggested that there is a major subtype of gastric cancer (“intestinal form”) that is the end result of a series of mutations and cell transformations that begin within 10 years of life. The mutation may be a nitroso compound formed by nitrite (from food or saliva) acting on naturally occurring nitrogen compounds in the upper digestive tract. Under normal conditions, these nitrosations