Economic evaluation of chemotherapy with mitoxantrone plus prednisone for symptomatic hormone-resistant prostate cancer: based on a Canadian randomized trial with palliative end points.

PURPOSE

To evaluate the economic consequences of the use of chemotherapy in patients with symptomatic hormone-resistant prostate cancer (HRPC) in the context of a previously published Canadian open-label, phase III, randomized trial with palliative end points.

PATIENTS AND METHODS

The trial randomized 161 patients to initial treatment with mitoxantrone and prednisone (M + P) or to prednisone alone (P) and showed better palliation with M + P. There was no significant difference in survival. A detailed retrospective chart review was performed of resources used from randomization until death of 114 of 161 patients enrolled at the three largest centers: these included hospital admissions, outpatient visits, investigations, therapies (which included all chemotherapy and radiation), and palliative care. Cancer center and community hospital costs were calculated by using the hotel approximation method and case costing from the Ontario Case Cost Project, respectively. Cost-utility analysis was performed by transforming the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 global quality-of-life item measured every 3 weeks on trial to an estimate of utility, and extending the last known value through to death or last follow-up.

RESULTS

The mean total cost until death or last follow-up by intention-to-treat was M + P CDN $27,300; P CDN $29,000. The 95% confidence intervals on the observed cost difference ranged from a saving of $9,200 for M + P (with palliative benefit) to an increased cost of $5,800 for M + P. The major proportion of cost (M + P 53% v P 66%; CDN $14,500 v $19,100) was for inpatient care. Initial M + P was consistently less expensive in whichever time period was used to compare costs. Cost-utility analysis showed M + P to be the preferred strategy with an upper 95% confidence interval for the incremental cost-utility ratio of CDN $19,700 per quality-adjusted life-year (QALY).

CONCLUSION

A treatment that reduces symptoms and improves quality of life has the potential to reduce costs in other areas. Economic factors should not influence the clinical decision as to whether to use M + P in a symptomatic patient.