Primary cancer of the small intestine and mutational analysis of the K-ras and p53 genes

Abstract:

A 69-year-old woman was admitted to Hokuso Shiroi Hospital because of recurrent pain in the lower right side of the abdomen. Small-intestinal cancer was strongly suspected after fluoroscopy of the small intestine. Laparotomy showed advanced cancer of the ileum, of complete annular constrictive type, 9.5 × 5 cm in size. Histologically it was moderately differentiated tubular adenocarcinoma. Neither visceral nor nodal metastases were found, and the patient has been well for the 20 months since surgery. The strong resemblance between the epidemiological characteristics of small-intestinal cancers and colorectal cancers prompted us to investigate the carcinogenetic mechanisms at the molecular level. A point mutation at codon 12 of the K-ras gene was found, while no alterations were noted in the p53 gene, whose mutations are frequent in colon cancers. The carcinogenetic mechanisms of the small-intestinal cancer we experienced may thus differ from those of colon cancers.