Background With emerging new technologies for diagnostics and treatment for breast cancer, there is a demand for updated breast cancer costs based on current clinical practice. The objectives of the current study were to (a) estimate recent societal costs of breast cancer in Sweden and (b) provide population-based patient-level cost estimates for health economic evaluations.

Methods This prevalence-based cost-of-illness study was based on 2019 data linking multiple Swedish national registers. The analysis employed a societal perspective considering direct health care, informal care, and productivity losses. Total costs were estimated using a bottom-up micro-costing approach. Direct costs were also estimated by subgroups, including age group, molecular subtype, breast cancer stage, and disease state defined by metastatic stage.

Findings 82,960 breast cancer patients diagnosed since 2008 were alive by the end of 2019. The annual societal cost of breast cancer in Sweden was 526 million euro, where the direct health care, informal care, and productivity losses accounted for 54%, 7%, and 40%, respectively. Costs of direct health care, including inpatient/outpatient care and prescribed drugs, varied by subgroups, where younger age, higher stage, and more adverse subtypes were associated with higher costs per patient-year. Patients with a diagnosis of de novo metastatic cancer incurred the highest cost per patient-year.

Interpretation Breast cancer represents a large economic burden in Sweden. The mean cost estimates per patient-year are informative to future health economic evaluations for breast cancer screening and treatment.

The authors have declared no competing interest.

This study was funded by the Swedish Research Council, VINNOVA, Swedish Cancer Society, and the European Union.

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For privacy protection, we undertook all analyses under the conditions of ethical approvals provided by the Swedish Ethical Review Authority (with approvals dnr 2019-02610 and dnr 2020-00886). Specifically, any analyses of potentially identifiable data were undertaken on secure network facilities with no reporting of results for individuals or small groups. For datasets with individual-level data, the datasets used an encrypted identifier and were pseudo-anonymised.

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Funding: the Swedish Research Council, VINNOVA, Swedish Cancer Society, and the European Union.

All data produced in the present work are contained in the manuscript.