Cost-effectiveness analysis of staging strategies in patients with regionally metastatic melanoma

Purpose: Variability exists regarding optimal staging for node-positive melanoma. Options include combinations of physical examination (PE), radiography, computed tomography (CT), and positron emission tomography (PET). Cost-effectiveness of regimens has never been investigated.

Methods: A modeled cost-effectiveness analysis was performed to examine the cost per surgery performed and per accurate diagnosis achieved with three staging regimens (PE/chest radiography, CT, PET/CT) for node-positive melanoma. Incremental cost-effectiveness ratios were used to compare regimens. Deterministic and probabilistic sensitivity analyses were undertaken to address variation in parameters. Costs are direct from the perspective of the Canadian single-payer system and 2012 valuations.

Results: Staging with PE/radiography is the least cost-effective option, resulting in greater costs than CT alone, and fewer accurate diagnoses. Compared to CT alone, PET/CT incurs greater incremental cost ($902.81CAD), but results in 4% fewer lymphadenectomies and 4% more accurate diagnoses. PET/CT costs $22,570.25CAD for each additional accurate diagnosis achieved compared to CT alone. Sensitivity analyses demonstrate that the optimal staging strategy is influenced by diagnostic test characteristics and the willingness-to-pay threshold, but robust to other varied parameters.

Conclusions: PE/radiography appears to be the least cost-effective staging regimen. The benefit of PET/CT over CT alone depends on a health system's priorities and willingness-to-pay.