Of the 1,519 colorectal cancer patients, 602 (39.6%), 66 (4.3%), and 26 (1.7%) were found to have KRAS, NRAS, and HRAS mutations, respectively.
The KRAS mutation was associated with fewer left-sided tumors, fewer poor differentiated tumors, more mucin component, and less lymphovascular invasion.
Patients with the NRAS mutation, but not the KRAS or HRAS mutation, had an insignificantly worse outcome.