HER2 overexpression is associated with shorter disease-free survival (DFS) following neoadjuvant systemic therapy (NST) of primary breast cancer (PBC) patients with gemcitabine (G), epirubicin (E) and docetaxel (Doc)

Abstract

11087 Background: To evaluate prognostic factors for disease-free survival (DFS) following NST with G, E and Doc of patients with PBC. Methods: From 1/02 to 12/04 113 patients with T2–4 N0–2 M0 PBC received either six cycles of GEDoc (G 800 mg/m2 day (d) 1+8, E 60–90 mg/m2 d 1, Doc 60–75 mg/m2 d 1 every three weeks; 63 patients) or five cycles of GE (1,250 mg/m2 d 1, E 90–100 mg/m2 d 1 every two weeks) sequentially followed by four cycles of Doc (80–100 mg/m2 d 1every two weeks) with prophylactic filgrastim. 71% of tumours were hormone receptor positive, 24% HER2 positive (3+ by immunohistochemistry), 46% grade 3. 28 patients (25%) achieved a pathologic complete response (pCR) defined as no invasive tumour residue in the removed breast tissue at surgery. 9 of these patients had non-invasive cancer residues in the breast, one patient showed persisting axillary lymph node involvement. Results: With a median follow up of 3.2 years there is no statistically significant difference in DFS, distant DFS (DDFS) and overall survival (OS) rates between patients with and without pCR (DFS 79 versus (vs) 81 %, p=0,61; DDFS 82 vs 84 %, p=0.69; OS 86 vs 91%, p=0.33). In a Cox proportional hazards model HER2 3+ before NST (hazard ratio (HR)= 4.7; 95% confidence interval (CI) 1.9 - 11.3; p=0.0006), positive hormone receptors before NST (HR=0.27; 95% CI 0.11 - 0.65; p=0.003) and clinically nodal involvement before NST (HR=3.3; 95% CI 1.2–9.1; p=0.02) were statistically significant prognostic factors for recurrence whereas tumour size and grade before NST, the achievement of pCR, nodal status at surgery and response after 6 weeks of NST did not reach statistical significance. Thus far, in multivariate analysis only Her2 3+ before NST retained its prognostic significance (HR= 2.8; 95% CI 1.03 - 7.5, p=0.04). Conclusions: With a median follow-up of 3.2 years in multivariate analysis only HER2 3+ is associated with shorter DFS following NST containing G, E and Doc for PBC. Thus far, there is no statistically significant prognostic value for pCR. No significant financial relationships to disclose.