Survey of KRAS, BRAF and PIK3CA mutational status in 209 consecutive Italian colorectal cancer patients

Cristina Bozzao, Dora Varvara, Marilidia Piglionica, Rosanna Bagnulo, Giovanna Forte, Margherita Patruno, Silvana Russo, Domenico Piscitelli, Alessandro Stella, Nicoletta Resta

Research output: Contribution to journalArticlepeer-review

Abstract

Molecular testing for KRAS and BRAF mutations in tumor tissue is a fundamental tool to identify patients with metastatic colorectal cancer (CRC) who are eligible for anti-EGFR monoclonal antibody therapy. We here report a molecular analysis by high-resolution melting analysis and direct sequencing of KRAS, BRAF and PIK3CA hot spot mutations in 209 Italian CRC patients. One hundred and ten patients (51%) were identified who were potentially nonresponders to anti-EGFR therapy: 90/209 patients (43%) harboring KRAS mutations, 13/117 (11.1%) with the V600E BRAF mutation, and 7/209 (3.3%) with mutations in PIK3CA exon 20. The prevalence of BRAF and PIK3CA mutations was significantly higher in patients older than 65 years (p=0.014 and p=0.018), while patients with triple-negative tumors were significantly younger than mutation carriers (p=0.000011). Patients with gene mutations also showed a trend towards preferential tumor location in the colon (p=0.026). Moreover, although involving a relatively small number of samples, we report the presence of a discordant mutational profile between primary tumors and secondary lesions (3/9 patients), suggesting that it is worthwhile to test other available tissues in order to better define the efficacy of targeted therapy. Further correlations of specific clinical features with tumor mutational profile could be helpful to predict the response of CRC patients to monoclonal antibody therapy.

Original languageEnglish
JournalInternational Journal of Biological Markers
Volume27
Issue number4
DOIs
Publication statusPublished - Oct 2012

Keywords

  • Anti-EGFR therapy
  • BRAF
  • Colorectal cancer
  • KRAS
  • PIK3CA

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cancer Research
  • Oncology
  • Pathology and Forensic Medicine

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