Original Article · Originalarbeit

Prolonged Survival of Patients Receiving Trastuzumab beyond Disease Progression for HER2 Overexpressing Metastatic Breast Cancer (MBC)
H-J. Stemmler^$; S. Kahlert^b; W. Siekiera^a; M. Untch^b; B. Heinrich^c; V. Heinemann^a

^aMedical Department III, ^bDepartment of Gynecology and Obstetrics, University Hospital of Munich, Großhadern, ^cOncological Practice, Augsburg, Germany

Onkologie 2005;28:582-586
(DOI: 10.1159/000088296)

  Summary

Background: The aim of this retrospective analysis was to evaluate the impact of trastuzumab-based regimens on the survival of patients with HER2-overexpressing metastatic breast cancer (MBC). The study specifically focussed on the influence of the continuation of trastuzumab-based treatment despite tumor progression on survival. Patients and Methods: Patients with HER2 overexpressing MBC were included in this retrospective analysis. HER2 overexpression was determined by the immunohistochemical staining score (DAKO Hercep Test™). Trastuzumab was applied at a loading dose of 4 mg/kg and a maintenance dose of 2 mg/kg. Results: Among 136 HER2 overexpressing patients (DAKO score 3+), 66 patients received first-line trastuzumab, 47 patients received trastuzumab as second-line therapy and 23 patients received trastuzumab beyond disease progression. There was no significant difference regarding the duration of trastuzumab-based treatment (first-line: 29.5 weeks vs. second-line: 25 weeks). Moreover, there was no difference in the response rate (first-line: 37.9% vs. second-line: 35.7%) or the median survival (p = 0.47 log rank). Patients who received = 2 trastuzumab-based regimens for MBC survived significantly longer compared to those who had received only 1 regimen (= 2 regimens: 62.4 months vs. 1 regimen: 38.5 months; p = 0.01 log rank). Conclusions: Trastuzumab is highly effective in the treatment of HER2 overexpressing MBC. Compared to historical controls, overall survival appears to be markedly prolonged, particularly in patients who received sequential trastuzumab-based treatment beyond disease progression.

Copyright © 2005 S. Karger GmbH, Freiburg