Potential antitumor effects of nitrogen-containing bisphosphonate in hormone receptor negative breast cancer patients with bone metastases

In Hae Park,Keun Seok Lee,Byung Ho Nam,Jungsil Ro,Youngmi Kwon

doi:10.1186/1471-2407-9-154

Abstract

BackgroundThis retrospective study evaluated, according to hormone receptor status, the antitumor effects of bisphosphonate especially on survival and disease progression in breast cancer patients with metastatic bone disease.MethodsOf 317 patients with initial bone metastasis and known breast cancer subtypes, 230 patients (72.6%) had hormone receptor (HR) positive tumors, and 87 patients (27.4%) had HR negative tumors. We assessed the primary outcome of overall survival (OS), after adjusting for other factors, comparing a group that received bisphosphonates (BPs) with a group that did not receive it.Results87.8% of HR positive and 69.0% of HR negative patients received BPs with a median number of 17.7 cycles. Although BPs treatment made no survival benefit in HR positive group, HR negative patients showed a significant prolonged survival when they received BPs treatment (hazard ratio = 0.56 [95% CI 0.34 to 0.91], P = 0.019). In multivariate analysis, disease free interval > 2 years (P = 0.036), a sum of metastatic sites < 3 (P = 0.034), and BP treatments (P = 0.007) were significant factors for survival in HR negative patients.ConclusionBisphosphonate treatment can result in a survival benefit in metastatic breast cancer patients with HR negative tumors.

Highlights

This retrospective study evaluated, according to hormone receptor status, the antitumor effects of bisphosphonate especially on survival and disease progression in breast cancer patients with metastatic bone disease
Study population and study assessments This retrospective study included a total of 317 breast cancer patients with initial bone metastases, whose hormone receptor (HR) status and HER2 status were known, and who were treated between June 2001 and July 2007 at the National Cancer Center Hospital, Korea
Baseline characteristics Among 317 patients with bone metastases at diagnosis, 262 (82.6%) patients were treated with BPs during followup

Summary

Introduction

This retrospective study evaluated, according to hormone receptor status, the antitumor effects of bisphosphonate especially on survival and disease progression in breast cancer patients with metastatic bone disease. Bone metastases are common in patients with advanced breast cancer. The median survival time after the diagnosis of bone metastases is approximately two years, it may increase with new treatment regimens [1]. The incidence of associated problems with metastatic bone disease (MBD), such as pathologic fracture or spinal cord compression, increases, and these complications may substantially reduce a patient's quality of life [1,2]. Bisphosphonates (BPs) have become the standard therapy for breast cancer patients with bone metastasis. It is clear that the bisphosphonates reduce both the symptoms and complications of bone involvement [3].

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