KRAS testing of patients with metastatic colorectal cancer in a community-based oncology setting: A retrospective database analysis

Background: in 2009,treatment guidelines were updated to recommend kras testing at diagnosis for patients with metastatic colorectal cancer (mcrc). we investigated kras testing rates over time and compared characteristics of kras-tested and not-tested patients in a community-based oncology setting. methods: adult patients with a diagnosis of mcrc from 2008-2011 were selected from the acorn data warehouse (acorn research llc,memphis,tn). text mining of physician progress notes and full chart reviews identified kras-tested patients,test dates,and test results (kras status). the overall proportion of eligible patients kras-tested in each calendar year was calculated. among kras-tested patients,the proportion tested at diagnosis (within 60 days) was calculated by year. univariate and multivariate analyses were used to compare patient characteristics at diagnosis between tested and not-tested cohorts,and to identify factors associated with kras testing. results: among 1,363 mcrc patients seen from 2008-2011,648 (47.5%) were kras-tested. among newly diagnosed mcrc patients,the rate of kras testing increased from 5.9% prior to 2008,to 13.9% in 2008,and then jumped dramatically to 32.3% in 2009,after which a modest yearly increase continued. the proportions of kras-tested patients who had been diagnosed in previous years but not tested previously increased from 17.7% in 2008 to 27.0% in 2009,then decreased to 19.0% in 2010 and 17.6% in 2011. among patients who were kras-tested,the proportions tested at the time of diagnosis increased annually (to 78.4% in 2011). patients more likely to have been tested included those with lung metastases,poor performance status,more comorbidities,and mcrc diagnosis in 2009 or later. conclusions: the frequency of kras testing increased over time,corresponding to changes in treatment guidelines and epidermal growth factor receptor inhibitor product labels; however,approximately 50% of eligible patients were untested during the study period. © 2015 carter et al.; licensee biomed central.