OBJECTIVES: To determine the health system costs and resources utilization of women diagnosed with breast cancer (BC) in Ontario, Canada.

METHODS: This was a retrospective, population-based study using provincial-level databases to identify women diagnosed with BC in the Ontario Cancer Registry between April 1, 2015 to March 31, 2019, with a minimum of 2 years follow-up. Collaborative staging (stages I-IV, unknown or missing [UNK/M]) was used. Total mean health care cost per patient (Canadian dollars) was calculated using an individual person-level costing methodology. Treatment-specific person-level costs related to radiation therapy and drug therapy were calculated separately. Healthcare resource utilization (HCRU) per patient per year was also determined.

RESULTS: We identified 32,037 women with BC, of which the majority were early stage (stage I=16,549, stage II=9,934, stage III=3,213, stage IV=898, UNK/M=1,443). The total mean BC diagnosis cost of the cohort was $52,752±$49,102, with costs increasing with advanced disease stage (stage 0=$32,519±$33,237, stage I=$38,621±$11,359, stage II=$59,950±$15,592, stage III=$85,041±$23,075, stage IV=$139,925±$97,930, UNK/M= $39,606±$13,269). Drug therapies were received by 80% of the cohort and stage IV diagnoses had the highest mean drug therapy cost at $78,090±$132,200. Radiation therapy was received by 90% of the cohort and stage III diagnoses had the highest mean radiation cost at $17,556±$7,931. Across all stages, the mean number of visits per year was 8.2 for cancer clinics, 4.9 for outpatient clinics, 28 for any physician encounters, and 15.4 for home care. In the first year after diagnosis, the mean number of visits were higher (26.5 for cancer clinics, 11.7 for outpatient clinics, 48.7 for any physician encounters and 25.8 for home care).

CONCLUSIONS: This analysis showed that the mean healthcare cost per BC patient was high and increased with advanced disease stage, and that HCRU was highest in the first year after diagnosis.