A comparison of systemic breast cancer therapy utilization in Canada (British Columbia), Scotland (Dundee), and Australia (Western Australia) with models of "optimal" therapy

Background: Different jurisdictions report different breast cancer treatment rates. Evidence-based optimal utilization models may be specific to the derived population. We compared predicted optimal with actual endocrine and chemotherapy utilization in British Columbia, Canada; Dundee, Scotland; and Perth, Western Australia. Design: Data were analyzed for differences in demography, tumour, and treatment. Epidemiological data were fitted to published Australian optimal radiotherapy utilization trees and region-specific optimal treatment rates were calculated. Optimal and actual systemic therapy rates from 2 population-based and 1 institution-based cancer registries were compared for patients diagnosed with breast cancer between 2000-2004, and 2002 for British Columbia. Results: Chemotherapy rates differed between British Columbia (32%), Perth (29%), and Dundee (24%, p = 0.014). Endocrine therapy rates were similar between British Columbia (56%), Perth (59%), and Dundee (64%, p > 0.05). Actual utilization rates were lower than optimal estimates for chemotherapy, but higher for endocrine therapy. Region-specific optimal utilization rates at diagnosis varied between 50-56% for chemotherapy, and 49-54% for endocrine therapy. Variation was attributed to local differences in demographics, and tumour stage. Conclusion: Actual treatment rates varied. There was lower than estimated optimal chemotherapy use but higher than expected use of endocrine therapy.