Estimation of an evidence-based benchmark for the optimal endocrine therapy utilization rate in breast cancer

There are no evidence-based benchmarks to establish optimal rates of use of endocrine therapy in the whole breast cancer population. Reported utilization rates vary widely. The aim of the study was to estimate the optimal proportion of breast cancer patients who should receive endocrine therapy based on treatment guideline recommendations and to compare this with actual treatment rates.

An optimal endocrine therapy utilization tree was constructed based on indications from evidence-based treatment guidelines. Frequency data on patient and tumour attributes were obtained from Australian cancer registries where possible and merged with the guideline recommendations to calculate the optimal utilization rate. These were compared with actual proportions obtained from published reports.

According to the best available evidence, the proportion of invasive breast cancer patients in whom endocrine therapy is indicated at diagnosis is 67%. Endocrine therapy is under-utilized in Australia (actual utilization rate 41%), and USA (35%), but approximate the benchmark rate in the UK (75%) and Italy (63%).

This evidence-based model provides a benchmark for optimal endocrine therapy utilization rates in the breast cancer population, and comparison of best practice evidence and actual treatment. The results show an underutilization of endocrine therapy in Australia and the USA, with more appropriate utilization in the UK and Italy.