303 - Clinical relevance of hormone receptors, Ki67 and HER-2 status as biomarkers surrogate for breast cancer molecular subtypes: a retrospective analysi...

Date 28 September 2012
Event ESMO Congress 2012
Session Publication Only
Topics Biomarkers
Breast Cancer
Presenter Alessandra Emiliani
Authors A. Emiliani1, A. Iannace1, G. Nigita2, T. Losanno1, G. Manna1, E. Franzese3, L. Frati1
  • 1Department Experimental Medicine, Sapienza University, Rome/IT
  • 2Division Of Surgery, Policlinico Casilino, Rome/IT
  • 3Internal Medicine, Sapienza University, 00187 - rome/IT

Abstract

Background

Early breast cancer (EBC) is a heterogeneous disease with distinct clinical, pathological, and molecular features and different treatment responsiveness and outcomes. Aim of study was to evaluate outcomes according to molecular subtypes breast cancer classified by four biomarkers using immunohistochemistry (IHC).

Patients and methods

We retrospectively reviewed 264 women with T1 N0/N+ breast cancer, referred to a single centre (1986 - 2009) and treated according to European guidelines. The relationships between classical prognostic factors, molecular subtypes classified by IHC and Disease free survivals (DFS) were analyzed.

Results

Univariate survival analysis showed a significantly different DFS at 5- and 7-ys for N0 and N+ patient populations, with a better outcome for patients with node-negative tumors (5ys: N0 = 95.9% vs. N + =88.8, p = 0.03; 7ys: N0 = 94.8% vs. N + =86.0%, p = 0.02). Nevertheless, long-term outcome (15-ys) displayed an inversion of the survival curves with a lower DFS rate of 65% in N0 vs. 86% in N+ patients (p < 0.0001). Regarding to Ki-67 tumor expression, patients with low Ki67 values (Ki-67 < 14%) had a better 5-ys DFS compared to patients with high Ki-67 (Ki-67 ≥ 14%). A significant difference in DFS has been observed also considering the tumor grading (G1 = 100%, G2 = 88%, G3 = 94.4%, p = 0.03). Based on molecular subtypes breast cancer classification by IHC, the 5-ys DFS rate was 98.4% for Luminal A (HR + , HER2-, Ki-67 < 14%), 96.3% for Luminal B HER2 negative (HR + , HER2-, Ki-67 ≥ 14%), 83.3% for Luminal B HER2 positive (HR + , HER + , any Ki-67), 83.6% for HER2-like (HR-, HER2+) and 74.5% for Basal-like tumors (HR-, HER2-).

Conclusions

At long-term follow-up, patients with T1N0 and patients with G2 EBC showed worst outcomes, probably because they are considered to have a low recurrence risk and not received adjuvant chemotherapy. Ki-67 expression is an important prognostic factor in hormone-receptors positive disease, allowing better definition of Luminal A and B molecular subtypes. Classic prognostic factors evaluated by IHC could be used as biomarkers surrogate for breast cancer molecular subtypes and might improve therapeutic decision in EBC patients.

Disclosure

All authors have declared no conflicts of interest.