272P - Long-term disease free survival (DFS) in patients with small breast cancer: clinical relevance of traditional and new prognostic factors in a retro...

Date 29 September 2014
Event ESMO 2014
Session Poster Display session
Topics Breast Cancer, Early Stage
Presenter Alessandra Emiliani
Citation Annals of Oncology (2014) 25 (suppl_4): iv85-iv109. 10.1093/annonc/mdu327
Authors A. Emiliani1, L. Filomeno2, A. Iannace3, T. Losanno3, G. Manna4, E. Franzese4, F.S. Di Lisa5, P. Seminara5
  • 1Department Experimental Medicine, Sapienza University, 00161 - Rome/IT
  • 2Clinical Medicine, Sapienza University, 00100 - Rome/IT
  • 3Department Experimental Medicine, Sapienza University, Rome/IT
  • 4Department Of Experimental Medicine, Sapienza University, Rome/IT
  • 5Clinical Medicine, Sapienza University, Rome/IT

Abstract

Aim

The incidence rate of small-size (T1) early-stage breast cancer (EBC) has increased. The risk of relapse is low, but there is a growing interest in identifying traditional and new prognostic factors to optimize therapeutic management. Patients with T1 EBC, especially if node-negative (N0), are excluded from tumor gene expression profiling due to the cost of this procedure. Immunohistochemistry (IHC)-based classification of breast cancer subtypes with confirmed prognostic and therapeutic implication is therefore recommended.

Methods

We reviewed the records of 511 patients diagnosed with T1 EBC referred to our oncology unit for adjuvant therapy. This retrospective study evaluated the different long-term clinical outcomes over 15 years and correlated with traditional (T, N, ER and PgR, Ki-67, HER2) and surrogate molecular subtype classification of the tumors using IHC prognostic factors.

Results

Patient characteristics were: median age 58.5 years (range 27-86). Tumor stage: T1a 74 (14.5%), T1b 120 (23.5%), T1c 317 (62.0%). Node status: N0 327 (64.0%), N1 184 (36.0%). Tumor grade: G1 144 (28.2%), G2 216 (42.3%), G3 151 (29.5%). Ki-67 index: <20% 327 (64.0%), >20% 184 (36.0%). HER2 overexpression: absent 378 (73.9%), present 80 (15.6%). IHC molecular subtype was: Luminal A 199 (38.9%), Luminal B HER2 negative 70 (13.7%), Luminal B HER2 positive 65 (12.7%), HER2 overexpression 14 (2.7%), Basal-like 41 (8.0%). In the overall population, the significant prognostic factors at 5 years were N0 vs. N1 (p = 0.05), PgR <20% vs. PgR >20% (p = 0.03), Ki-67 index <20% vs. Ki-67>20% (p = 0.04) and Luminal A vs. Luminal B HER2 negative (p = 0.05). At 15 years of follow-up, only Ki-67 index confirmed its prognostic value (p = 0.04). In the N0 subgroup of patients DFS curves were significantly different for Ki-67 index <20% vs. Ki-67 >20% both at 5-year (p = 0.01) and 15-year follow-up (p = 0.03).

Conclusions

The DFS curves of T1 EBC patients at 5 years underline the prognostic relevance of the cut-off of 20%, both for PgR expression and Ki-67 index as well as IHC-based molecular subtypes Luminal A vs. Luminal B HER2 negative. With regard to long-term outcome, only Ki67-index seems to be useful for identifying different prognostic tumor subgroups. These results were particularly important to improving current management of N0 EBC patients with different risk factors.

Disclosure

All authors have declared no conflicts of interest.