A Systematic Literature Review (SLR) of Economic Burden of Patients with Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative (HR+/HER2–) Metastatic Breast Cancer (MBC) with at Least One Prior Therapy

OBJECTIVES: With the HR+/HER2– mBC treatment landscape evolving between endocrine therapy (ET), chemotherapy, and novel therapies, economic burden may impact treatment decisions, especially in later-line settings. This SLR summarizes the current evidence of economic evaluations, costs, and resource use among adults with HR+/HER2– mBC and ≥1 prior therapy in the metastatic setting.

METHODS: The MEDLINE, Embase, Cochrane Library, and governmental databases as well as relevant congresses were searched to identify publications between 2012-2022. Two independent researchers screened for English-language publications on economic evaluation, costs, and resource use among the target population.

RESULTS: Of 2491 publications identified, 12 economic burden publications were included; 7 focused on third-line or later (3L+) settings (claims database analyses, n=2; observational studies, n=2; physician survey, cost-of-illness model, and cohort study, n=1 each). Key drivers of healthcare resource utilization included inpatient (IP) and outpatient (OP) services. Consistent across lines of therapy, higher direct healthcare costs (eg, medical, hospitalization, pharmacy, and OP costs) were incurred by patients receiving chemotherapy versus other therapies (eg, ET, CDK4/6 inhibitors, and estrogen receptor antagonists), primarily due to IP costs. In 4 US/Canadian studies published between 2016-2018, 3L+ chemotherapy led to direct healthcare costs (2014 USD) between $6731-$16,129 per person per month (PPPM; IP costs, $3261-$7041 PPPM) compared with $2954-$6158 PPPM (IP costs, $1187-$2833 PPPM) for 3L+ ET-based therapy. Lower productivity drove higher indirect costs for patients receiving chemotherapy versus other therapies in treatment line agnostic studies. No studies estimated indirect costs by treatment line or indirect costs in a US population.

CONCLUSIONS: Patients with HR+/HER2– mBC receiving chemotherapy versus other therapies incurred higher direct healthcare costs driven by IP costs and higher indirect costs driven by lower productivity. This SLR also highlights the lack of recent studies evaluating economic burden in later-line settings and studies examining indirect costs in the US.