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