Burden of breast cancer with brain metastasis: a French national hospital database analysis

Abstract

Objective:

Incidence of breast cancer with brain metastases (BCBM) is increasing, especially among patients over-expressing HER2. Epidemiology on this sub-type of cancer is scarce, since cancer registries carry no information on the HER2 status. A retrospective database analysis was conducted to estimate the burden of BCBM, especially among HER2-positive patients in a secondary objective.

Methods:

Patients with a new diagnosis of BCBM carried out between January and December 2008 were identified from the national hospital database using the International Disease Classification. Patients receiving a targeted anti-HER2 therapy were identified from the national pharmacy database. Hospital and pharmacy claims were linked to estimate the burden of HER2-positive patients. Data on hospitalizations were extracted to describe treatment patterns and healthcare costs during a 1-year follow-up. Predictors of treatment cost were analyzed through multi-linear regression analysis.

Results:

Two thousand and ninety-nine BCBM patients were identified (mean age (SD) = 57.8 (13.6)), of whom 12.2% received a targeted anti-HER2 therapy; 79% of patients had brain metastases associated with extracranial metastases, and the attrition rate reached 82%. Patients received mostly palliative care (47.4%), general medical care (40.6%), and chemotherapy (35.0%). The total annual hospital cost of treatment was 8,426,392€, representing a mean cost of 22,591€ (±14,726) per patient, mainly influenced by extracranial metastases, surgical acts, and HER2-overexpression (p < 0.0001).

Conclusions:

The database linkage of hospital and pharmacy claims is a relevant approach to identify sub-type of cancer. Chemotherapy was widely used as a systemic treatment for breast cancer rather than for local treatment of brain metastases whose morbi-mortality remains high. The variability of treatment costs suggests clinical heterogeneity and, thus, extensive individualization of protocols.

Key words::

• Breast cancer
• Brain metastases
• Claims analysis
• Cost-of-illness
• Treatment pattern
• Database linkage
• HER2 positive

Transparency

Declaration of funding

Funding for the study was provided by GlaxoSmithKline and had no influence on the study design, execution, and publication of results.

Declaration of financial/other relationships

L.B. has a doctoral fellowship financed in part by GlaxoSmithKline and the Association Nationale pour la Recherche et la Technologie (ANRT). At the time of the study, F.-E.C. was employee at GlaxoSmithKline. F.M. (Stat Process) and A.V. (HEVA) are employees of a Contract Research Organization (CRO). G.V.-T. declares no conflicting interests. I.D.-Z. declares having participated to advisory boards for the pharmaceutical industry, including GlaxoSmithKline.

Acknowledgments

The authors wish to thank Baptiste Jouaneton (HEVA, Lyon, France) for technical help in data collection and Adam Doble (Foxymed, Paris, France) for writing assistance of the manuscript. The results of this study were partly presented at the 13th Annual European Congress of International Society for Pharmacoeconomics and Outcomes Research; November 6–9th 2010, Prague, Czech Republic (PCN59).