218P - Prognostic estimates of Ki-67 percentage drop after neoadjuvant chemotherapy (NAC) in luminal B (lumB) and triple negative breast cancer (TNBC)

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Breast Cancer, Locally Advanced
Breast Cancer
Presenter Javier Pascual
Citation Annals of Oncology (2017) 28 (suppl_5): v68-v73. 10.1093/annonc/mdx364
Authors J. Pascual1, B. Rojas-Garcia1, V. Peg2, S. Diaz-Botero3, E. Zamora1, E. Muñoz Couselo1, M. Oliveira1, P. Gomez Pardo1, J. Perez Garcia1, F. Ruiz-Pace4, C. VIAPLANA4, S. Escrivá1, L. Garrigos1, M. Arumi1, M. Espinosa-Bravo3, J. Cortés5, I. Rubio3, C. Saura1, R. Dienstmann4, M. Bellet Ezquerra1
  • 1Medical Oncology Department, Vall d’Hebron University Hospital Institute of Oncology (VHIO), 08035 - Barcelona/ES
  • 2Anatomical Pathology, Vall d'Hebron University Hospital, Barcelona/ES
  • 3Breast Pathology Unit, Vall d'Hebron University Hospital, 08035 - Barcelona/ES
  • 4Oncology Data Science Group (odyssey), Vall d'Hebron Institute of Oncology (VHIO), 08035 - Barcelona/ES
  • 5Medical Oncology Department, Vall d’Hebron University Hospital Institute of Oncology (VHIO), 08035 - barcelona/ES

Abstract

Background

Pathologic complete response (pCR) and residual cancer burden (RCB) after NAC are validated prognostic markers in BC. We assessed the impact of adding Ki-67% drop (baseline biopsy - surgery) to distant metastasis relapse-free survival (dRFS) models containing CP factors plus post-treatment stage (MDACC CPS score), estrogen receptor status and tumor grade (MDACC CPS+EG score).

Methods

Records from 341 patients (pts) with lumB/HER2 neg (baseline Ki67 >20%) or TNBC who received NAC from 2008 to 2015 at our hospital were reviewed. Uni- and multivariate Cox models were constructed and concordance-index (c-index) calculated.

Results

Pts: median age 47 years (24-83), 60% lumB and 40% TNBC, 62% stage 2, 38% stage 3. pCR: 12% lumB, 32% TNBC (p 

Conclusions

Our data support the addition of Ki-67% drop after NAC in lumB and TNBC to existing dRFS online outcome calculators. In the context of RCB 2/3, Ki-67 > = 20% drop is mainly seen in lumB/HER neg tumors. Importantly, Ki-67 < 20% drop identifies a high-risk population that may be eligible to clinical trials with novel therapeutic interventions in the adjuvant setting.

Clinical trial identification

Legal entity responsible for the study

Vall d'Hebron University Hospital

Funding

Vall d'Hebron Institute of Oncology

Disclosure

M. Oliveira: Consulting or Advisory Role in Roche-Genentech and Puma Biotechnology. Research Funding in AstraZeneca and Genentech/Roche. R. Dienstmann: Consulting or Advisory Role in Roche-Genentech and in Astellas Pharma. Research Funding in Merck. All other authors have declared no conflicts of interest.