These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Infrequent K-ras codon 12 mutation in serrated adenomas of human colorectum.
    Author: Ajioka Y, Watanabe H, Jass JR, Yokota Y, Kobayashi M, Nishikura K.
    Journal: Gut; 1998 May; 42(5):680-4. PubMed ID: 9659164.
    Abstract:
    BACKGROUND: Serrated adenoma is a new morphological subtype of colorectal adenoma. The lesion provides a distinct morphological route to carcinoma, but the underlying genetic changes have not yet been investigated. AIMS: To determine the frequency of K-ras mutation in serrated adenoma. METHODS: The frequency of K-ras codon 12 point mutation in 20 serrated adenomas, five atypical hyperplastic polyps, and 58 sporadic polypoid adenomas was investigated by nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. RESULTS: Although most of the serrated adenomas were large (average size 11.4 mm) and polypoid, K-ras codon 12 point mutation was detected in only one of the 20 (5%), which is a significantly lower frequency than that in sporadic polypoid adenomas (18/60; 30%) (p = 0.017). No mutation was detected in the atypical hyperplastic polyps. Three of 20 (15%) serrated adenomas contained a focus of carcinoma in situ, indicating their malignant potential and the existence of a serrated adenoma-carcinoma sequence, but no mutation was detected in the foci of carcinoma in situ. CONCLUSIONS: K-ras mutation is uncommon in serrated adenomas, indicating a different spectrum of genetic alterations in these lesions from those in typical polypoid sporadic adenomas. This subtype of colorectal adenoma represents a new genetic pathway in the histogenesis of colorectal carcinoma.
    [Abstract] [Full Text] [Related] [New Search]