Clinical Implication of KRAS Mutation Variants in Patients With Resected Colon Cancer

This study evaluated the clinical implication of KRAS proto-oncogene, GTPase (KRAS) mutation variants in patients with resected colon cancer (CC).

We retrospectively reviewed 482 patients diagnosed with CC who underwent curative surgical resection at Kyungpook National University Chilgok Hospital. The inclusion criteria were: Pathologically diagnosed with primary CC; stage I-III CC according to the 7th edition of American Joint Committee on Cancer staging system; and with available test results for KRAS mutation status. In total, 345 patients met these criteria and were included in this study.

Among the 345 patients, 140 (40.6%) exhibited KRAS mutations, with their incidences as follows: 90/140 (64.3%) in exon 2 codon 12, 37/140 (26.4%) in exon 2 codon 13, 1/140 (0.1%) in exon 3 codon 59, 7/140 (5.0%) in exon 3 codon 61, and 5/140 (3.6%) in exon 4 codon 146. KRAS mutation status was not a significant prognostic factor for disease-free survival or overall survival. Although there were no significant differences in survival between patients with exon 2 codon 12 and exon 2 codon 13 mutations, poorer disease-free survival (p=0.085) and overall survival (p=0.005) were seen in those with exon 3 codon 61 mutation than in others.

KRAS mutation status was not correlated with survival, but exon 3 codon 61 mutation might be a factor for poor prognosis in patients after resection of CC.