title: KRAS testing on colo-rectal carcinoma cytological imprints.
abstract: Anti-EGFR monoclonal antibodies, cetuximab, and panitumumab, are administrated under the condition that advanced colo-rectal cancer (CRC) carries a wild-type KRAS gene. Thus, clinicians request pathologists to genotype KRAS before treatment. In the near future routine mutation testing at the same time of the surgery may be implemented. The reliability of a rapid KRAS testing on ex vivo cytological samples obtained by direct scraping of the colon tumour tissue is here evaluated. A consecutive series of 20 surgically resected, primary CRC specimens was analysed. Fresh tissue from CRC was scraped with a scalpel blade, smeared on uncoated glass slides, air-dried and Diff-Quik stained to ensure malignant cell presence. The same tissue area was also histologically processed. Exon 2 KRAS gene mutations were evaluated on both cytological and histological specimens by dideoxy sequencing and by the DxS KRAS Mutation Test Kit (DxS, Manchester, England). Data obtained on on imprint cytology and matched histological samples showed full concordance; however, the mutation frequency was slightly higher (35%) by the DxS KRAS Mutation Test Kit than by the dideoxy sequencing (30%). Thus, colon cancer imprint cytology sample is a reliable biospecimen for both dideoxy-sequencing and DxS KRAS Mutation Test Kit analysis and it may be useful to abbreviate the KRAS assay turnaround time.
authors.affiliation: Dipartimento di Scienze Biomorfologiche e Funzionali, Università di Napoli Federico II, Naples, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Malapelle
authors.forename: Claudio
authors.initials: C
authors.lastname: Bellevicine
authors.forename: Anna
authors.initials: A
authors.lastname: Russo
authors.forename: Maria
authors.initials: M
authors.lastname: Salatiello
authors.forename: Lucio
authors.initials: L
authors.lastname: Palombini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Troncone
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001706:Biopsy; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D003937:Diagnosis, Differential; D005091:Exons; D005838:Genotype; D006801:Humans; D020125:Mutation, Missense; D000077544:Panitumumab; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D011933:Reagent Kits, Diagnostic; D017422:Sequence Analysis, DNA; D018631:ras Proteins / Q000235:genetics*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D011933:Reagent Kits, Diagnostic; D000077544:Panitumumab; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab