title: Changes of KRAS Exon 2 Codon 12/13 Mutation Status in Recurrent Colorectal Cancer.
abstract: Colorectal cancer (CRC) is a heterogeneous disease presenting with a wide spectrum of morphological and molecular characteristics sometimes even within the same patient. To understand the mechanisms of oscillations in the KRAS status we evaluated the collective of CRC patients tested using allele-specific PCR and Sanger-sequencing. Mutant KRAS allele was observed in 43.3% of cases. Repeated analysis of KRAS status in recurrent tumors or metastases was performed in 18/665 cases and a total of 6 cases with different KRAS status was found. In three cases the histological pattern of the tumor was identical. In one patient different histology and molecular status was seen between the primary and the recurrent tumor samples. In two further cases localization, histological type and KRAS mutational status all supported the occurrence of synchron/metachron colorectal tumors. In conclusion, both the progression of the original disease but also multiple tumor formation may contribute to mutation status differences during the course of colorectal carcinoma.
authors.affiliation: Department of Pathology, Medical Center, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary.
authors.forename: Ottó
authors.initials: O
authors.lastname: Dócs
authors.forename: Ferenc
authors.initials: F
authors.lastname: Fazakas
authors.forename: Nóra Lugosiné
authors.initials: NL
authors.lastname: Horváth
authors.forename: László
authors.initials: L
authors.lastname: Tóth
authors.forename: Csilla
authors.initials: C
authors.lastname: András
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Horváth
authors.forename: Gábor
authors.initials: G
authors.lastname: Méhes
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D003062:Codon / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics; D005091:Exons / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D012189:Retrospective Studies; D015996:Survival Rate; D018631:ras Proteins / Q000235:genetics*
chemical_list: D003062:Codon; D004273:DNA, Neoplasm; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins