Abstract
Background: Trastuzumab (TZB), is approved in France in adjuvant setting since 2005 for patients with HER2-positive breast cancer. The effectiveness of this treatment is well established, but little is known about the impact of pre-exposure to this drug in non metastatic disease and its effectiveness during its reintroduction in the metastatic disease.
Methods: We extracted from the database of two Medical Oncology Departments from University Cancer Institute - University Pierre & Marie Curie (IUC-UPMC), clinical parameters of patients treated in first-line HER2 positive metastatic breast cancer with treatments including TZB as the only antiHER2 treatment, between 2005 and 2011. We analyzed the impact of this treatment in patients who received adjuvant TZB and also in patients who did not.
Results. During this period, 456 patients were treated with TZB for a non metastatic HER2 positive disease, and 103 patients for a metastatic HER2 positive disease. Among the 456 patients treated in the (neo)adjuvant setting, the relapse rate was 3% (n = 16). The remaining 87 patients treated with first-line metastatic TZB were not previously treated with TZB in the adjuvant setting (n = 68) or had HER2 positive metastatic disease at time of initial diagnosis (n = 19). For patients previously exposed to TZB (n = 16), response rate (RR) of first-line treatment including TZB was 57% (95% CI: 35-81%) and time to failure treatment (TTF) was 243 days (95% CI: 114 to 330 days). For patients who have not been previously exposed to TZB (n = 87), the RR of first-line treatment including TZB was 61% (95% CI: 49-74%) and TTF was 267 days (95% CI: 182-343 days).
Conclusions: Despite the lack of direct comparison, it does not appear that treatment including TZB in non metastatic disease, will influence the efficacy of first-line treatment of metastatic featuring TZB reexposure.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-06.
Volume 73, Issue 24 Supplement
