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KRAS testing and epidermal growth factor receptor inhibitor treatment for colorectal cancer in community settings
Jennifer Webster1, Tia L Kauffman, Heather Spencer Feigelson
1Center for Health Research, Kaiser Permanente Northwest, Portland, OR 97227, USA.
Background:
In metastatic colorectal cancer (mCRC), mutations in the KRAS gene predict poor response to EGF receptor (EGFR) inhibitors. Clinical treatment guidelines now recommend KRAS testing if EGFR inhibitors are considered. Our study investigates the clinical uptake and utilization of KRAS testing.
Methods:
We included 1,188 patients with mCRCs diagnosed from 2004 to 2009, from seven integrated health care delivery systems with a combined membership of 5.5 million. We used electronic medical records and targeted manual chart review to capture the complexity and breadth of real-world clinical oncology care.
Results:
Overall, 428 patients (36%) received KRAS testing during their clinical care, and 266 (22%) were treated with EGFR inhibitors. Age at diagnosis (P = 0.0034), comorbid conditions (P = 0.0316), and survival time from diagnosis (P < 0.0001) influence KRAS testing and EGFR inhibitor prescribing. The proportion who received KRAS testing increased from 7% to 97% for those treated in 2006 and 2010, respectively, and 83% of all treated patients had a KRAS wild-type genotype. Most patients with a KRAS mutation (86%) were not treated with EGFR inhibitors. The interval between mCRC diagnosis and receipt of KRAS testing decreased from 26 months (2006) to 10 months (2009).
Conclusions:
These findings show rapid uptake and incorporation of this predictive biomarker into clinical oncology care.
Impact:
In this delivery setting, KRAS testing is widely used to guide treatment decisions with EGFR inhibitors in patients with mCRCs. An important future research goal is to evaluate utilization of KRAS testing in other delivery settings in the United States.
Insights
KRAS testing rapidly increased in metastatic colorectal cancer care, guiding EGFR inhibitor use. Most patients with KRAS mutations did not receive these inhibitors, indicating biomarker integration into treatment decisions.
Area of Science:
- Oncology
- Molecular Diagnostics
- Clinical Biomarkers
Background:
- KRAS mutations in metastatic colorectal cancer (mCRC) predict poor response to EGFR inhibitors.
- Clinical guidelines recommend KRAS testing for patients considered for EGFR inhibitor therapy.
Purpose of the Study:
- To investigate the clinical uptake and utilization of KRAS testing in patients with mCRC.
- To assess how KRAS testing guides the prescription of EGFR inhibitors in real-world clinical practice.
Main Methods:
- Retrospective analysis of 1,188 mCRC patients diagnosed between 2004-2009.
- Data collected from electronic medical records and manual chart reviews across seven integrated health care systems.
Main Results:
- KRAS testing increased from 7% (2006) to 97% (2010) among treated patients.
- 36% of patients received KRAS testing; 22% received EGFR inhibitors.
- 83% of treated patients had a KRAS wild-type genotype; 86% of patients with KRAS mutations did not receive EGFR inhibitors.
Conclusions:
- Rapid uptake and integration of KRAS testing as a predictive biomarker in mCRC clinical oncology care.
- KRAS testing is widely utilized to guide EGFR inhibitor treatment decisions in this healthcare setting.
- Future research should evaluate KRAS testing utilization in diverse US healthcare settings.
