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Comparative Study
. 1994 Feb;85(2):147-51.
doi: 10.1111/j.1349-7006.1994.tb02075.x.

Lower incidence of K-ras codon 12 mutation in flat colorectal adenomas than in polypoid adenomas

S Yamagata  1 , T Muto, Y Uchida, T Masaki, T Sawada, N Tsuno, T Hirooka
Affiliations
Comparative Study

Lower incidence of K-ras codon 12 mutation in flat colorectal adenomas than in polypoid adenomas

S Yamagata et al. Jpn J Cancer Res. 1994 Feb.

Abstract

In order to clarify genetic changes in flat adenomas, K-ras codon 12 point mutations were examined in 56 flat adenomas, 81 polypoid adenomas and 42 cancers of colon and rectum. The mutation frequency in flat adenomas was 23% (13/56), significantly lower than that in polypoid adenomas (67%: 54/81) and cancers (76%: 32/42). Even mildly dysplastic adenomas or small (less than 5 mm) adenomas showed higher mutation incidence in polypoid type (62%, 57%) than in flat type (23%, 19%). Among flat adenomas, flat elevated lesions exhibited relatively higher mutation frequency than completely flat or depressed ones. As for cancers, 14 tumors (33%) contained mutations only in a minor tumor cell population, indicating that these mutations occur at a late stage of tumorigenesis. These results suggest that the adenoma-carcinoma sequence through flat adenomas may be different from that through polypoid adenomas, and genetic changes may be heterogeneous in colorectal carcinogenesis.

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References

    1. ) Bos , J. L. , Fearon , E. R. , Hamilton , S. R. , Verlaan‐de Vries , M. , van Boom , J. H. , van der Eb , A. J. and Vogelstein , B.Prevalence of ras gene mutations in human colorectal cancers . Nature , 327 , 293 – 297 ( 1987. ). - PubMed
    1. ) Forrester , K. , Almoguera , C. , Han , K. , Grizzle , W. E. and Perucho , M.Detection of high incidence of K‐ras oncogenes during human colon tumorigenesis . Nature , 327 , 298 – 303 ( 1987. ). - PubMed
    1. ) Burmer , G. C. and Loeb , L.Mutations in the KRAS2 oncogene during progressive stage of human colon carcinoma . Proc. Natl. Acad. Sci. USA , 86 , 2403 – 2407 ( 1989. ). - PMC - PubMed
    1. ) Fearon , E. R. , Cho , K. R. , Nigro , J. M. , Kern , S. E. , Simons , J. W. , Ruppert , J. M. , Hamilton , S. R. , Preisinger , A. C. , Thomas , G. , Kinzler , K. W. and Vogelstein , B.Identification of a chromosome 18q gene that is altered in human colorectal cancers . Science , 247 , 49 – 56 ( 1990. ). - PubMed
    1. ) Vogelstein , B. , Fearon , E. R. , Hamilton , S. R. , Kern , S. E. , Preisinger , A. C. , Leppert , M. , Nakamura , Y. , White , R. , Smits , A. M. M. and Bos , J. L.Genetic alterations during colorectal‐tumor development . N. Eng. J. Med. , 319 , 525 – 532 ( 1988. ). - PubMed

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