P-313 - K-ras mutation as prognostic factor in our patients with rectal cancer

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Biomarkers
Rectal Cancer
Presenter D. Scepanovic
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors D. Scepanovic, M. Pobijakova, A. Masarykova, A. Hurakova, M. Lukacovicova, Z. Dolinska
  • National Cancer Institute of Slovakia, Bratislava/SK



The K-ras gene is one of the commonly mutated oncogenes associated with colorectal cancer. In particular, approximately 30%–40% of colorectal cancers harbor a K-ras mutation. K-ras mutations in colorectal cancers have been associated with poorer survival and increased tumor aggressiveness. However, its prognostic significance for patients with colorectal cancer remains inconclusive.

Purpose: - We analysed our group of patients with rectal cancer to see if the K-ras mutation correlated with their prognosis.


Hundred sixteen patients with rectal cancer who had analysis of K-ras gene were included in the retrospective analysis from January 2004 to December 2010. K-ras mutation has been demonstrated in 16.4% of our patients. Both groups of patients (with negative K-ras and positive K-ras mutations) were homogeneous regarding to the age of patients and stage of disease. All of patients had locally advanced stage of rectal cancer and they were treated with preoperative chemoradiotherapy, followed by radical surgery. We evaluated distant metastasis rate, local recurrence rate and survival depending from the K-ras status.


Median follow-up time was 48 months (range, 12 to 96 months) for whole group of patients. Distant metastasis occurred in 22% patients with K-ras negative and 32% patients with K-ras positive mutations. There was not statistically significant difference between these two groups of patients (p = 0.3785, Fisher‘s exact test). Local recurrence rate was 3% in group with K-ras negative and 5% with K-ras mutations (p = 0.5161). In the group with K-ras negative, 86% of patients live and 79% in the group of patients with K-ras positive mutations. There was not statistically significant difference regarding to their survival (p = 0.4921).


K-ras gene mutation had not influence on distant metastases and local recurrence rates, as well as, survival and did not correlate with the prognosis of our patients with rectal cancer.