Treatment patterns and duration in post-menopausal women with HR+/HER2− metastatic breast cancer in the US: a retrospective chart review in community oncology practices (2004–2010)

Abstract

Background:

Clinical guidelines prefer endocrine therapy (ET) as initial treatment for post-menopausal women with hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2−) metastatic breast cancer (mBC). Chemotherapy (CT) should be reserved for patients who develop symptomatic visceral disease or have no clinical benefit after three sequential ET regimens. It is unclear if real-world clinical practice reflects these guidelines.

Objective:

To describe treatment patterns and treatment durations by lines of therapy for ET and CT among post-menopausal HR+/HER2− mBC patients.

Methods:

Charts were reviewed from a network of community-based oncology practices of eligible patients who had progressed after initiating adjuvant or first-line treatment for mBC between 1 January 2004 and 30 September 2010. Extracted chart data included demographics, treatment histories, and outcomes. Treatment duration was estimated using Kaplan–Meier estimators.

Results:

A total of 144 patients were studied. Patients received a median of two lines of ET, and <10% had three or more lines of ET before receiving CT. From first line to second line, the median treatment duration was 11.6 to 4.9 months for ET overall; 13.8 to 10.5 months for anastrozole; 18.6 to 7.0 months for letrozole; and 5.1 to 2.9 months for fulvestrant. For CT, the median duration was 5.1 months in the first line and 3.7 months and below in subsequent lines.

Conclusion:

During the study period (1 January 2004 – 30 September 2012), most patients received <3 lines of ET before receiving CT. The drop in median duration of ET from first to second line suggests that single agent ETs might not be as effective beyond the first line. A key limitation of this study was the small sample size. In addition, more research is needed to further investigate the short treatment duration of fulvestrant across early lines of therapy (which could indicate lack of efficacy).

Keywords: :

• Chemotherapy
• Endocrine therapy
• HR+/HER2-
• Metastatic breast cancer
• Post-menopausal
• Treatment duration
• Treatment patterns

Transparency

Declaration of funding

This analysis was supported by Novartis Pharmaceuticals Corporation.

Declaration of financial/other relationships

A.R.M., P.L.L., J.E.S., E.Q.W., E.O., Z.Z. and C.K. have disclosed that they are employees of Analysis Group Inc., a company that received funding from Novartis to conduct this study. Y.H. has disclosed that she is an employee of Novartis and holds stock in the company.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgement

We thank Yan Song, an employee of Analysis Group, Inc., who contributed to the preparation and editing of the manuscript.