Objectives: Initial androgen deprivation therapy (ADT) for metastatic prostate cancer with combined androgen blockade (luteinizing-hormone releasing hormone agonist [LHRH agonist] plus antiandrogen) is not recommended in British Columbia (BC). However, this is difficult to monitor since ADT includes concurrent antiandrogen for the first month of LHRH agonist to prevent disease flare. We describe the prevalence of CAB use in BC and its financial impact.
Methods: This was a population-based, retrospective analysis. Patients started on LHRH agonist in January 2005 to December 2006 were identified from the BC Cancer Agency database. CAB was defined as greater than 1 month of antiandrogen concurrently with LHRH agonist. Incremental cost of CAB was based on an average 18 months of therapy from the pivotal CAB study. Incremental cost-effectiveness ratio (ICER) was based on life-year gained (LYG) from the Prostate Cancer Trialists' Collaborative Group meta-analysis. Estimated financial impact for 2007-2008 was based on an annual increase by 5.5% in prevalence of prostate cancer in BC.
Results: A total of 2751 patients were identified. CAB was used in 607 patients (22%), associated with an incremental cost of CDN$1768 and ICER of CDN$11,220/LYG per patient. Total incremental cost was CDN$1,073,176 and estimated to be CDN$1,398,644 for January 2007 to December 2008.
Conclusion: Nearly one-quarter of patients were treated with CAB for metastatic prostate cancer even though it was not recommended in BC. Additional cost of CAB use was considerable, at CDN$1768 per patient. With increased prevalence of prostate cancer, this has important budget implication for funding agencies which do to recommend CAB.