In patients with unprovoked VTE, does the addition of FDG PET/CT to a limited occult cancer screening strategy offer good value for money? A cost-effectiveness analysis from the publicly funded health care systems.

INTRODUCTION: Unprovoked venous thromboembolism (VTE) may be the first manifestation of an undiagnosed cancer. We assessed the cost-effectiveness of 18 F-Fluorodesoxyglucose Positron Emission/Computed Tomography (FDG PET/CT) plus limited screening and limited screening strategies in patients with unprovoked VTE from the perspectives of the Ontario (Canada) and French health care systems.

METHODS: We conducted a cost-effectiveness analysis based on a published randomized controlled trial of 394 patients aged 18 years or older who were diagnosed with unprovoked VTE. We obtained data with respect to efficacy and health care utilization from the published trial. The primary measure of effectiveness was the number of avoided cases of delayed cancer diagnosis and the secondary measure of effectiveness was the quality adjusted life year (QALY) at the end of the study in each group. We used generalized linear models to estimate incremental cost-effectiveness ratios (ICER) while controlling for patient demographic and clinical characteristics. Results were presented as the incremental cost to avoid one case of delayed cancer diagnosis and the incremental cost per QALY gained. The 95% confidence intervals (CIs) were estimated using bootstrap re-sampling procedures with 5000 iterations.

RESULTS: Compared to a limited screening strategy, the ICER of limited strategy plus FDG PET/CT scan was C$ 26,840.19 (95% CI: C$ 24,046.51; C$ 34,581.53) per one avoided case of delayed cancer diagnosis from the Ontario health system perspective and €16,370.45 (95% CI: € 9904.48; € 39,578.91) per one avoided case of delayed cancer diagnosis from the French health system perspective. The probabilities that addition of FDG PET/CT to limited screening is cost-effective rose with increasing willingness to pay values. Compared with the limited screening, the extensive screening was associated with C$ 3412.85 per QALY gained (95% CI: 1463.89; -13,935.88) from the Ontario health system perspective and €2162.83 per QALY gained (95% CI 958.78; -10,544.42) from the French health system perspective.

CONCLUSION: Addition of a FDG PET/CT for occult cancer diagnosis was associated with better health outcomes (fewer cases of delayed cancer diagnosis and greater QALYs) and a higher cost from the perspective of publicly funded health care systems; the cost-effectiveness results are however highly uncertain.