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.
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.
Authors: J L Bos; E R Fearon; S R Hamilton; M Verlaan-de Vries; J H van Boom; A J van der Eb; B Vogelstein Journal: Nature Date: 1987 May 28-Jun 3 Impact factor: 49.962
Authors: T Muto; J Kamiya; T Sawada; F Konishi; K Sugihara; Y Kubota; M Adachi; S Agawa; Y Saito; Y Morioka Journal: Dis Colon Rectum Date: 1985-11 Impact factor: 4.585
Authors: S M Powell; N Zilz; Y Beazer-Barclay; T M Bryan; S R Hamilton; S N Thibodeau; B Vogelstein; K W Kinzler Journal: Nature Date: 1992-09-17 Impact factor: 49.962
Authors: G B Baretton; F Autschbach; S Baldus; H Bläker; G Faller; H K Koch; C Langner; J Lüttges; M Neid; P Schirmacher; A Tannapfel; M Vieth; D E Aust Journal: Pathologe Date: 2011-02 Impact factor: 1.011
Authors: J R Jass; K G Biden; M C Cummings; L A Simms; M Walsh; E Schoch; S J Meltzer; C Wright; J Searle; J Young; B A Leggett Journal: J Clin Pathol Date: 1999-06 Impact factor: 3.411