KRAS status in patients with colorectal cancer peritoneal carcinomatosis and its impact on outcome

Background: KRAS mutated colorectal cancers (CRC) are reported to be associated with a poor response to anti-EGFR monoclonal antibody therapy and poor prognosis. We studied the rates of KRAS mutated tumors in patients with peritoneal carcinomatosis from CRC and investigated the association of KRAS status with specific clinicopathologic factors. Methods: A retrospective observational study of tumor specimens from 23 patients with peritoneal carcinomatosis from CRC was performed using standard genomic DNA sampling techniques to identify KRAS mutations. Correlation between clinicopathologic factors and KRAS mutation status was performed using the Fisher exact test or χ² test, as appropriate. Results: Eleven (48%) of 23 patients had KRAS mutations. There were no statistically significant correlations in patient demographics, tumor pathology, surgical evaluation, treatments, or survival outcomes for peritoneal carcinomatosis between patients with KRAS mutations or wild-type KRAS status. Conclusion: The prevalence of KRAS mutation in CRC patients with peritoneal carcinomatosis is 48% in this preliminary study and clinicopath- ologic factors appear to be independent of mutation status.