Quantifying the Clinical and Economic Consequences of DPYD Genotype-Guided Fluoropyrimidine Dosing in Colorectal Cancer Patients: A Case Study from Ontario, Canada
Abstract
Colorectal cancer patients receiving fluoropyrimidine-based chemotherapy are at risk of experiencing treatment-related adverse events (AEs), and mortality. The risk is increased for patients with reduced dihydropyrimidine dehydrogenase activity due to impaired-function variants in the DPYD gene. DPYD genotype-guided treatment has been shown to reduce treatment-related AEs and corresponding costs through the administration of lower doses for DPYD variant carriers. This thesis compared clinical and economic outcomes between DPYD genotype-guided patients and standard-of-care patients derived from historic and contemporaneous control groups using health administrative data from Ontario, Canada. There were no differences in toxicity prevalence, or cancer-related mortality between the DPYD genotype-guided group and most control groups following inverse probability weighting. The DPYD genotype-guided group had a $5,241 reduction in per-patient cancer costs when compared with the historic control, but a $1,401 - $1,530 increase when compared with the contemporaneous controls. Future research is suggested to better understand the mixed results.