Relationship of Ki-ras mutations in colon cancers to tumor location, stage, and survival: A population-based study

Some previous studies have demonstrated significant results between Ki-ras mutations and tumor stage, survival, and/or other clinical variables, where as others have not. We therefore evaluated the significance of codons 12 an d 13 Ki-ras mutations in a large population-based study of 1413 individuals with colon cancer. Ki-ras mutations were identified in similar to 32% of t umors. Codon 12 mutations were significantly more common in proximal than d istal tumors (29.1% versus 20.5%; P < 0.01) and in tumors of advanced stage . Tumors from men were more likely to have transition mutations and codon 1 2 G->A mutations. After adjusting for age and stage, the codon 13 G->A muta tion was associated with a 40% (95% confidence interval, 0.95-2.0) increase in short-term mortality from colon cancer. In conclusion, this population- based study demonstrates important relationships between Ki-ras mutations a nd stage, survival, tumor location, and gender.