Abstract: It has been determined that a specific metaplastie lineage that contains immunoreactivity for a trefoil polypeptide, spasmolytic peptide, is associated with and gives rise to the vast majority of human adenocarcinomas. The identification of this Spasmolytic Polypeptide Expressing Metaplasia (SPEM) is a major factor for grading of biopsies of the stomach to assess risk for gastric cancer. It also forms the basis of a method for serological screening for those at risk for gastric cancer. In a preferred embodiment, antibodies to spasmolytic peptide (hSP) are used in immunostaining of biopsies of gastric tissue obtained by endoscopy for grading biopsies Those patients having these cells, characterized by a morphology more typical of a type of cell present normally in the intestine and not stomach, Brunner's gland cells, are at risk of developing adenocarinoma.