P-0253 - K-ras in metastatic colorectal cancer

Date 28 June 2014
Event World GI 2014
Session Poster Session
Topics Biomarkers
Colon Cancer
Rectal Cancer
Presenter Mourad Belmadi
Citation Annals of Oncology (2014) 25 (suppl_2): ii14-ii104. 10.1093/annonc/mdu165
Authors M. Belmadi1, S. Belhadef2, H. Saidi2, H. Mahfouf2
  • 1Hospital Rouiba, Algiers/DZ
  • 2Hospital, Rouiba, Algiers/DZ

Abstract

Introduction

KRAS oncogene is involved in colorectal carcinogenesis in 22 to 45% of cases. The purpose was to determine the frequency, types and distribution of Kras mutations.

Methods

K-ras studies were carried out in primary tumors and metastases of colo-rectal cancer in 59 patients diagnosed with CRC between 2009–2013 at Rouiba Medical Oncology Department. 23 women (w) aged 53 ± 20 years and 36 men (m) aged 57.5 ± 22.5 years.

Results

Primary tumors were located in the colon and rectum in 43 (73%) and 16 patients (27%), respectively. In 35 patients (59.23%) K-ras was WT (12w/23m), median age at diagnosis was 54.63 years, 82,8% were immediately metastatic at diagnosis and 20 patients had liver metastases, median overall survival in WT patients was 23 months, 10 deaths and time from diagnosis to death in this group was 33.1 months. In 22 patients (40.67%) K-ras mutations were demonstrated (9w/13m). The main point mutations were located in codon 12 (77.27%), G12D (27.27%), G12C (22.72%), G12V (18.18%), G12A (4.54%), G12S (4.54%) and (22.72%) at codon 13 (G13D). Median age at diagnosis was 56.63 years, 81,8% were immediately metastatic at diagnosis and 12 had liver metastases, median overall survival in the mutated group was 19.45 months, 7 deaths and time from diagnosis to death in this group was 20 months. All patients received Capox/Capiri +/- bevacizumab in the first and second line, in the WT patients Cetuximab was used in the second line in one patient and in the third line in 07 patients.

Conclusion

In this series, 40.67% of colorectal cancer tissue samples had K-ras mutations. KRAS-mutated CRC was associated with statistically significantly poorer survival after diagnosis than KRAS-wild-type CRC. Their frequency was similar to those reported in the literature.