Patients’ Journey and Healthcare Costs of Relapsing Early Breast Cancer in a Setting of Italian Real Clinical Practice

OBJECTIVES: This analysis provided an up-to-date description of HR+HER2- early breast cancer (eBC) population in Italy, focusing on the rate of relapses and the related economic burden for the National Health System (NHS).

METHODS: Administrative databases from healthcare providers corresponding to ~6,000,000 inhabitants were screened to identify women with hospitalization discharge diagnosis for BC and BC-related surgery between Jan-2010 and Aug-2023. HR+HER2- subtype, stage, and relapses were detected by data linkage between pathology and administrative databases. HR+HER2- eBC patients with ≥12 months of available data pre- and post-surgery were included. Adherence to adjuvant endocrine therapy (ET) was evaluated as a medication possession ratio ≥80%. Healthcare costs during the 2^nd year post-surgery (months: 13^th-24^th) were compared in relapsing vs non-relapsing patients.

RESULTS: Of 17,638 women complying the inclusion criteria (age: 63.7±13.5 years, follow-up 4.4±2.2 years), 5251 (29.8%) experienced a relapse with a median (IQR) time to relapse of 0.8 (1.3) years. Among 742 patients with histologically confirmed stage II/III BC in the pathology database, 36.8% had a relapse. After stratification by tumor stage, the relapse rate grew along with stage (from 32.0% stage IIA to 71.1% stage IIIC). The proportion of adherent patients calculated among non-relapsing survivors decreased from 64.7% at 1-year to 49.0% at 5-year post-surgery. Healthcare costs during the 2^nd year after surgery were significantly higher in relapsing (N=3106) vs non-relapsing (N=11,228) survivors, either overall expenses (€4724 vs €2253, p<0.001) or single items, with hospitalizations and drugs as the most impactive.

CONCLUSIONS: The analysis showed that nearly 3 of 10 HR+HER2- eBC patients with stage II/III experienced a relapse, highlighting an unmet clinical need. This finding deserves attention from the perspective of the NHS, since relapse resulted in more than doubled total healthcare expenses.