Objective: To establish whether specific K-ras alterations are predictive of less aggressive tumor behavior and subsequently those patients who are most likely to benefit from resection of hepatic metastases from colorectal carcinoma.
Design: Evaluation of long-term survivors of hepatic resection for metastases of colorectal carcinoma (median survival, 85 months).
Results: DNA, extracted from 26 paraffin-embedded hepatic metastases from 19 patients, was analyzed using single-strand conformation polymorphism and direct sequence analysis of codons 12 and 13 of the K-ras gene. Seven of 19 patients were found to harbor K-ras mutations. A similar frequency and spectrum of K-ras mutational events was detected in 14 patients with short-term survival following pathologic diagnosis of hepatic metastasis.
Conclusions: Neither the presence of a K-ras mutational event nor the precise nucleotide change are predictive of less aggressive tumor behavior, and genetic alterations at this locus alone cannot be used to select patients undergoing resection of hepatic metastases from colorectal carcinoma.