Objectives: Guidelines recommend routine KRAS testing among patients with metastatic colorectal cancer (mCRC) to determine eligibility for targeted therapies. Genomic profiling, using next generation sequencing (NGS) based technology, identifies multiple mutations simultaneously. Understanding potential predictors of NGS testing is crucial to assess clinical utility of the test. Methods: Electronic health records and tumor registry data of mCRC patients were accessed. Baseline characteristics of patients tested with NGS panel or KRAS mutation detection test (timeframe: Jan 1, 2010 - April 10, 2015) were compared. Colorectal cancer was defined by ICD-O codes for site and histology. Metastatic stage was identified using ICD-9 codes for metastases, initial cancer stage reported, or chemotherapies received. Analysis was limited to mCRC diagnosis after Jan 1st, 2010. Predictive univariate logistic regression models were used to control for potential confounding. Results: Of 584 patients meeting eligibility criteria, 60 patients were NGS ± KRAS tested and 140 patients were KRAS-only test. Median (mean) age at diagnosis was 61(58) year for NGS group vs. 57(58) year in KRAS-only group (p= 0.399). For NGS and KRAS-only groups, majority of mCRC patients were white (80% and 81%, respectively; p= 0.772), males (59% and 52%, respectively; p= 0.403), and initially diagnosed at stage IV (53% and 65%, respectively; p= 0.490). Metastatic sites or their number were not different between groups (p= 0.348 for number of metastatic sites), but year of mCRC diagnosis was different (p< 0.0001). Univariate analysis showed increased use of NGS panels with more recent diagnoses (p < 0.0001). Conclusions: Patients tested with NGS were similar to KRAS-only tested patients. The only predictor of NGS testing was the year of mCRC diagnosis. As NGS testing cost is almost 10 times KRAS testing cost, an ongoing cost-effectiveness analysis is being conducted to assess the value of NGS testing in mCRC patients.
Biltaji, E., Stenehjem, D., Schiffman, J., & Brixner, D. (2016). Predictors of NGS Testing in Metastatic Colorectal Cancer. Value in Health, 19(3), A169. https://doi.org/10.1016/j.jval.2016.03.1530