A Retrospective Study on the Efficacy of Trastuzumab in HER2-Positive and Tamoxifen-Refractory Breast Cancer with Brain Metastasis

BioDrugs. 2016 Feb;30(1):33-40. doi: 10.1007/s40259-015-0156-z.

Abstract

Background and objective: The role of trastuzumab in breast cancer with brain metastasis is still in discussion. This study was conducted to investigate the efficacy of trastuzumab in the management of human epidermal growth factor receptor 2 (HER2)-positive, tamoxifen-refractory breast cancer with brain metastasis.

Methods: This retrospective study was conducted between January 2008 and December 2012. A total of 33 patients receiving trastuzumab treatment for HER2-positive, tamoxifen-refractory breast cancer with brain metastasis were assigned to the experimental group, while a matched group of 35 patients who received systemic therapy without trastuzumab were assigned to the control group. Data on the patient characteristics and clinical outcomes were collected and evaluated.

Results: Patients in the trastuzumab group showed a significantly better response to treatment than those in the control group (p = 0.025). Univariate and multivariate Cox proportional regression analyses indicated that progression-free survival was significantly longer in patients receiving trastuzumab therapy than in the control group (hazard ratio [HR] 2.213 [p = 0.003] and HR 3.056 [p < 0.001], respectively) and significantly shorter in patients with two or more extracranial metastases (HR 0.417 [p = 0.002] and HR 0.317 [p < 0.001], respectively). Furthermore, patients on trastuzumab treatment experienced longer overall survival than patients in the control group (HR 2.844 [p < 0.001] and HR 4.017 [p < 0.001], respectively), while shorter overall survival was seen in patients with two or more extracranial metastases (HR 0.524 [p = 0.021] and HR 0.430 [p = 0.005], respectively) and in those receiving capecitabine-based therapy as compared with anthracycline-based therapy (HR 0.558 [p = 0.030] and HR 0.449 [p = 0.011], respectively).

Conclusion: Trastuzumab was found to benefit patients with HER2-positive, tamoxifen-refractory breast cancer with brain metastasis by improving progression-free and overall survival.

MeSH terms

  • Adult
  • Aged
  • Anthracyclines / administration & dosage
  • Antineoplastic Agents / therapeutic use*
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / secondary
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / pathology
  • Capecitabine / administration & dosage
  • Disease-Free Survival
  • Female
  • Humans
  • Middle Aged
  • Proportional Hazards Models
  • Receptor, ErbB-2 / metabolism
  • Retrospective Studies
  • Survival Rate
  • Tamoxifen / administration & dosage
  • Trastuzumab / therapeutic use*
  • Treatment Outcome

Substances

  • Anthracyclines
  • Antineoplastic Agents
  • Tamoxifen
  • Capecitabine
  • ERBB2 protein, human
  • Receptor, ErbB-2
  • Trastuzumab