title: Mutation analysis of KRAS in primary colorectal cancer and matched metastases by means of highly sensitivity molecular assay.
abstract: Mutation analysis of KRAS is needed before starting treatment with anti-EGFR monoclonal antibodies in patients with metastatic colorectal cancer (CRC). In most of the cases, testing is performed on primary tumors, assuming that KRAS mutation status does not change in metastasis although correlation studies gave conflicting results. We evaluated the KRAS status concordance rate between primary tumors and related metastasis using a highly sensitive molecular assay. Forty-five primary tumors and related metastases from patients with CRC (28/45 male-62.2% and 17/45 female-37.8%; mean age 66.4 years) were analyzed by using TheraScreen: KRAS mutational kit. Metastatic samples were collected from lymph nodes (8/45-17.8%) and visceral sites (37/45-82.2%); 23 were synchronous (49%) and 22 were metachronous (51%), obtained after a mean of 30.8 months after the first diagnosis of CRC. Twenty-eight patients had KRAS mutations in both primary CRC and related metastases (62.2%). No differences in type and frequency of mutations were identified, despite different metastatic sites and time of onset of metastatic disease. Our results indicate that the mutation status of KRAS is the same in primary CRC and metastasis, suggesting that in clinical practice, KRAS testing can be performed on both tumor tissues when using a highly sensitive molecular assay.
authors.affiliation: Laboratory of Molecular Pathology, Department of Health Sciences, University of Eastern Piedmont "Amedeo Avogadro", Novara, Italy. miglio@med.unipmn.it
authors.forename: Umberto
authors.initials: U
authors.lastname: Miglio
authors.forename: Rosanna
authors.initials: R
authors.lastname: Mezzapelle
authors.forename: Alessia
authors.initials: A
authors.lastname: Paganotti
authors.forename: Sara
authors.initials: S
authors.lastname: Allegrini
authors.forename: Claudia
authors.initials: C
authors.lastname: Veggiani
authors.forename: Jlenia
authors.initials: J
authors.lastname: Antona
authors.forename: Sergio
authors.initials: S
authors.lastname: Gentilli
authors.forename: Guido
authors.initials: G
authors.lastname: Monga
authors.forename: Oscar
authors.initials: O
authors.lastname: Alabiso
authors.forename: Renzo
authors.initials: R
authors.lastname: Boldorini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000556:secondary*; D004252:DNA Mutational Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D013997:Time Factors; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins