Cost-effectiveness of KRAS testing in metastatic colorectal cancer patients in the United States and Germany.

The objective of this study was to determine the cost-effectiveness of testing for KRAS mutations before administering EGFR inhibitors such as cetuximab and panitumumab for patients with advanced metastatic colorectal cancer (mCRC) in the United States and Germany. We developed a lifetime Markov model of costs and survival associated with treating mCRC patients to assess the impact of KRAS testing before administering EGFR inhibitor-containing chemotherapy regimens. Overall, combination therapies involving cetuximab plus irinotecan/FOLFIRI had a better life expectancy (25.83 weeks) than cetuximab or panitumumab alone. Use of KRAS testing (assuming KRAS mutant patients receive only irinotecan) was equally effective and saved $12,428 per patient in the United States. When KRAS mutant patients received best supportive care, the life expectancy decreased slightly (24.26 weeks vs. 25.83 weeks) and the costs decreased by $13,501 in the United States and €9,560 in Germany. For patients treated with cetuximab alone, use of KRAS testing to identify mutations lowered costs by $8,040 per patient in the U.S. analysis and €3,856 per patient in the German analysis. For patients treated with panitumumab alone, use of KRAS testing to identify mutations lowered costs by $7,546 per patient in the U.S. analysis and €4,612 per patient in the German analysis. Model results were sensitive to the cost of chemotherapy regimens and the prevalence of KRAS mutations in the population. Under most scenarios, using KRAS testing to select patients for EGFR inhibitor therapy saved $7,500-$12,400 per patient in the United States and €3,900-€9,600 per patient in Germany with equivalent clinical outcomes.