High concordance of KRAS status between primary colorectal tumors and related metastatic sites: implications for clinical practice.

Abstract

PURPOSE:

Several studies have suggested that KRAS somatic mutations may predict resistance to cetuximab- and panitumumab-based treatments in metastatic colorectal cancer (CRC) patients. Nevertheless, most experiences were conducted on samples from primaries. The aim of this study was to evaluate the grade of concordance in terms of KRAS status between primaries and related metastases.

PATIENTS AND METHODS:

We analyzed KRAS codon 12 and 13 mutations from formalin-fixed sections of 107 CRC primaries and related metastases. Eight pairs were excluded from the analysis because of the low amount of tumor tissue in the available samples. The main characteristics were: 50 men, 49 women; median age at diagnosis, 71 years (range, 41-84). The metastatic sites analyzed were the liver in 80 patients (80.8%), lung in seven patients (7.1%), and other sites in 12 patients (12.1%).

RESULTS:

A KRAS mutation was found in 38 (38.4%) primary tumors and in 36 (36.4%) related metastases. The rate of concordance was 96.0% (95% confidence interval, 90.0%-98.9%). Discordance was observed in only four (4%) patients.

CONCLUSIONS:

Our results indicate that the detection of KRAS mutations in either primary or metastatic tumors from patients with CRC is concordant and this assessment could be used to predict response to targeted therapies such as cetuximab and panitumumab.

• Authors: Daniele Santini, Fotios Loupakis, Bruno Vincenzi, Irene Floriani, Irene Stasi, Emanuele Canestrari, Eliana Rulli, Paolo Enrico Maltese, Francesca Andreoni, Gianluca Masi, Francesco Graziano, Giacomo Giulio Baldi, Lisa Salvatore, Antonio Russo, Giuseppe Perrone, Maria Rosa Tommasino, Mauro Magnani, Alfredo Falcone, Giuseppe Tonini, Annamaria Ruzzo
• Journal: The oncologist (Oncologist) Vol. 13 Issue 12 Pg. 1270-5 (Dec 2008) ISSN: 1549-490X [Electronic] England
• PMID: 19056857 (Publication Type: Journal Article)

Chemical References

• KRAS protein, human
• Proto-Oncogene Proteins
• ErbB Receptors
• Proto-Oncogene Proteins p21(ras)
• ras Proteins

Topics

• Adult
• Aged
• Aged, 80 and over
• Colorectal Neoplasms (genetics, pathology)
• ErbB Receptors (antagonists & inhibitors)
• Female
• Genes, ras
• Humans
• Male
• Middle Aged
• Mutation
• Neoplasm Metastasis
• Proto-Oncogene Proteins (genetics)
• Proto-Oncogene Proteins p21(ras)
• Retrospective Studies
• ras Proteins (genetics)