Dissertation Title:  "Cost-Effectiveness of Imaging and Surgery in Patients with Colorectal Cancer Liver Metastases"

This study examines options for diagnostic imaging and surgical management of patients with hepatic metastases from colorectal carcinoma (CRC). The objective of the study was to better understand the cost, effectiveness, and cost-effectiveness of hepatic resection ("metastasectomy") in these patients, and to investigate the impact of different pre- and post-operative diagnostic imaging regimens on the costs and effectiveness of therapy. In order to perform the analysis, we developed and validated a series of state-transition (Markov) decision models. These models were used to investigate: 1) the likelihood of missing liver metastases, given certain assumptions concerning test sensitivity, operative threshold, and the number of metastases present; 2) the cost-effectiveness of hepatic metastasectomy in patients with limited hepatic metastases; and 3) the impact of diagnostic imaging on the cost-effectiveness of therapy. Our principal findings were as follows: 1) hepatic metastasectomy, within the general bounds established for the analysis, appears to be a relatively cost-effective procedure for the management of patients with limited hepatic metastases from colorectal carcinoma; 2) more aggressive approaches to imaging and resection should be preferred over less aggressive approaches in this patient population; 3) there appears to be a survival benefit, at a reasonable cost, even in patients who ultimately develop post-operative recurrences following metastasectomy; and, 4) when considering the cost and effectiveness of a variety of management strategies, across a population of patients with hepatic metastases, the benefits associated with more frequent pre- and post-operative imaging and more sensitive imaging tests are sufficient to justify their increased cost. Our results strongly support an aggressive approach to imaging and treatment in patients with potentially resectable metastases from colorectal carcinoma. From a cost-effectiveness perspective, it appears that hepatic metastasectomy should be encouraged, and that all surgeons and oncologists should be encouraged to expand their criteria for patient selection for this procedure. However, it is critical that the results of our studies be confirmed by actual clinical experience, and also by detailed and prospective collection of data concerning the costs and outcomes associated with imaging and surgery in this patient group.