The economic impact of cytoreductive surgery and tyrosine kinase inhibitor therapy in the treatment of advanced gastrointestinal stromal tumours: a Markov chain decision analysis.
OBJECTIVE
The current first-line treatment for patients with recurrent or metastatic gastrointestinal stromal tumours (GIST) is management with tyrosine kinase inhibition (TKI). There is an undefined role for surgery in the management of these patients. This study uses a cost analysis to examine the economic impact of treating patients with TKI in combination with surgery at different time-points in their treatment trajectories.


METHODS
A Markov chain decision analysis was modelled over a 2-year time horizon to determine costs associated with surgery in combination with imatinib mesylate (IM) or sunitinib malate (SU) in seven scenarios varied by TKI agent, dose and disease status (stable versus localised progressive disease). Rates of disease progression, surgical morbidity, mortality and adverse drug reactions were extracted from the existing literature. Deterministic sensitivity analyses were performed to examine changes in cost due to variations in key variables.


RESULTS
The least-costly scenario was to perform no surgery. The most costly scenario was to perform surgery on patients with localised progressive disease on IM 800 mg. The overall range of costs clustered within approximately $47,000 (USD). Variations in surgical cost, surgical mortality and cost of IM demonstrated thresholds for changing the least-costly scenario within plausible tested ranges.


CONCLUSIONS
Costs of surgical intervention at different time-points within the treatment course of patients with advanced GIST fluctuate within a relatively narrow range, suggesting that costs arise primarily from the administration of TKI. The decision to pursue cytoreductive surgery should not be based on cost alone. Future studies should incorporate health-state utilities when available.
Division of Surgical Oncology, Brigham and Women's Hospital, Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, United States. Electronic address: n.lookhong@utoronto.ca.
Nicole J
NJ
Look Hong
Division of Urologic Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, United States.
Steven L
SL
Chang
Division of Surgical Oncology, Brigham and Women's Hospital, Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, United States.
Chandrajit P
CP
Raut
D003131:Combined Modality Therapy / Q000191:economics; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000191:economics / Q000601:surgery*; D006801:Humans; D008390:Markov Chains; D018803:Models, Economic; D017063:Outcome Assessment, Health Care / Q000191:economics / Q000379:methods; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*
D047428:Protein Kinase Inhibitors
Cost; Cytoreduction; GIST; Sarcoma; Surgery