A cost-outcome analysis of adjuvant postmastectomy locoregional radiotherapy in premenopausal node-positive breast cancer patients.

PURPOSE

To calculate cost-effectiveness and cost-utility ratios for adjuvant postmastectomy locoregional radiotherapy in premenopausal node-positive breast cancer patients and to place these ratios in the context of generally accepted medical expenditures.

MATERIALS AND METHODS

A spreadsheet-based activity costing model using 1997 Canadian (cdn) capital, operating, and administrative costs has been used to identify, from the institutional perspective, the incremental cost of adding radiotherapy to surgery and chemotherapy for this group of patients. Outcome data were derived from two recently published clinical trials and were converted to discounted incremental life years and quality-adjusted life years gained. Recommended health economics principles were employed in the quantification of both costs and outcomes, and a sensitivity analysis was performed. Three referenced publications provide a context within which to evaluate the calculated cost-effectiveness and cost-utility ratios.

RESULTS

The incremental cost of adjuvant radiotherapy for this group of patients is calculated to be approximately $7,000cdn in 1997 Canadian dollars and in the Canadian socialized health-care environment. Based on published work the discounted incremental outcome benefit is calculated to be 0.5 life years or 0.45 quality-adjusted life years at ten years. Thus, cost effectiveness and cost-utility ratios are estimated to be $14,000cdn and $15,600cdn, respectively.

CONCLUSION

Within the context of generally accepted medical expenditures, adjuvant postmastectomy locoregional radiotherapy for premenopausal node-positive breast cancer patients would be regarded as a cost-effective treatment strategy.