Evaluation of cost-effectiveness of early KRAS testing in high-risk recurrence colorectal cancer patients in Italy.

Abstract

e14113 Background: KRAS testing is relevant for the choice of the most appropriate first-line therapy for metastatic colorectal cancer (CRC) patients (pts). Early KRAS testing in surgically resected CRC pts at high risk of recurrence might result cost-effective when the results of KRAS test are not available in acceptable time following the diagnosis of metastatic disease. Methods: This study adopted the Delphi technique to reach a consensus to define high risk recurrence CRC and KRAS test optimal timing. We used validated decision analyses models employed by technology assessment agencies (NICE and SMC) for the assessment of KRAS wild-type CRC pts. Alternative therapeutic strategies include FOLFOX4, FOLFIRI, FOLFOX4 + cetuximab, FOLFIRI + cetuximab, FOLFOX4 + bevacizumab. We adapted the models to take into account early KRAS testing in high risk pts for which the test would not be available on time to drive appropriate treatment. The models have been populated with Italian specific cost data incorporating pts’ access schemes. Results: Issues related to KRAS testing were proposed to 108 Italian oncologists and pathologists through two subsequent questionnaires. The following parameters to define CRC pts at high risk of recurrence were identified: pT4, high grading, pN2, intestinal occlusion-perforation, isolated peritoneal carcinomatosis surgically removed and/or positive peritoneal washing and/or removed ovarian metastases. A time interval of more than 10-15 days for KRAS testing was defined as a limit for the therapeutic choices. Early KRAS testing in high risk CRC pts generates incremental cost effectiveness ratios between 6,000 and 13,000 Euro per quality adjusted life year (QALY) gained, depending on alternative treatment of choice. In extensive sensitivity analyses, ICER’s were always below 15,000 Euro per QALY gained, far within the 60,000 Euro/QALY gained threshold currently accepted in Italy. Conclusions: In metastatic CRC a time interval of more than 10-15 days for the response of KRAS testing limits the therapeutic choices. Early KRAS testing in high-risk CRC pts who would not have KRAS test in a reasonable time when they develop metastases is a cost effective strategy.