EXPRESSION OF C-MYC MESSENGER-RNA AS AN AID IN HISTOLOGIC DIFFERENTIATION OF ADENOMA FROM WELL-DIFFERENTIATED ADENOCARCINOMA IN THE STOMACH

Background. Using prospective follow-up studies, the authors examined the value of the expression of c-myc mRNA in biopsy specimens obtained from elevated gastric lesions as an aid in the differentiating betwee n adenomas and well differentiated elevated-type adenocarcinomas. Meth ods. By in situ hybridization, the authors determined the expression o f c-myc mRNA in biopsy specimens of elevated gastric lesions. The 31 p atients who had borderline lesions with and without overexpression of c-myc were followed with repeated endoscopic examinations and gastric biopsies. Results. Endoscopic follow-up examinations showed that gastr ic cancer was detected in 5 of 11 patients (46%) with elevated lesions that stained positively for c-myc mRNA during an observation period o f 15 months (range, 2-32 months). The cancers were confirmed histologi cally in gastrectomy specimens. No cancers were found in patients with elevated lesions that stained negatively. The difference was statisti cally significant (P < 0.01). Conclusions. The overexpression of c-myc mRNA may present a new tool for distinguishing between adenomas and w ell differentiated adenocarcinomas of the elevated type.