KRAS Mutation Detection in Paired Frozen and Formalin-Fixed Paraffin-Embedded (FFPE) Colorectal Cancer Tissues

International Journal of Molecular Sciences

Jérome Solassol¹  Jeanne Ramos²  Evelyne Crapez³  Majda Saifi⁴  Alain Mangé¹  Evelyne Vianès¹  Pierre-Jean Lamy³  Valérie Costes² 

[1] Department of Cellular Biology, Center Hospital University, Montpellier 34000, France; E-Mails:;University of Montpellier I, Montpellier 34000, France; E-Mails:;Department of Biology, Centre Lutte Contre Cancer Val d’Aurelle, Montpellier 34000, France; E-Mails:;Department of Pathology, Center Hospital University, Montpellier 34000, France; E-Mail:

关键词: genotyping;    KRAS;    fixative;   

DOI  :  10.3390/ijms12053191

来源: mdpi

【 摘 要 】

KRAS mutation has been unambiguously identified as a marker of resistance to cetuximab-based treatment in metastatic colorectal cancer (mCRC) patients. However, most studies of KRAS mutation analysis have been performed using homogenously archived CRC specimens, and studies that compare freshly frozen specimens and formalin-fixed paraffin-embedded (FFPE) specimens of CRC are lacking. The aim of the present study was to evaluate the impact of tissue preservation on the determination of KRAS mutational status. A series of 131 mCRC fresh-frozen tissues were first analyzed using both high-resolution melting (HRM) and direct sequencing. KRAS mutations were found in 47/131 (35.8%) using both approaches. Out of the 47 samples that were positive for KRAS mutations, 33 had available matched FFPE specimens. Using HRM, 2/33 (6%) demonstrated suboptimal template amplification, and 2/33 (6%) expressed an erroneous wild-type KRAS profile. Using direct sequencing, 6/33 (18.1%) displayed a wild-type KRAS status, and 3/33 (9.1%) showed discordant mutations. Finally, the detection of KRAS mutations was lower among the FFPE samples compared with the freshly frozen samples, demonstrating that tissue processing clearly impacts the accuracy of KRAS genotyping.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.