Abstract 5327
Background
Pathologic complete response (pCR) is a surrogate marker of a better relapse-free (RFS) and overall survival (OS), particularly in HER2 overexpressing and triple-negative breast cancer (TNBC) subtypes. Our aim is to assess the impact of HER2 expression level on pCR, in patients with luminal or TNBC treated with neoadjuvant chemotherapy (NAC).
Methods
We conducted a retrospective analysis in luminal and TN non-metastatic breast cancer patients, addressed to cancer center Georges François Leclerc in Dijon for NAC. Hormone receptor and HER2 expression were centrally assessed according to CAP/ASCO criteria. The pathologic response was dichotomized in pCR and non-pCR and evaluated according to Chevalier classification.
Results
Between 2007 and 2018, 761 patients (pts) were recorded, of which 263 (34.5%) had TNBC and 498 (65.5%) luminal-HER2 negative BC. Among TNBC, 189 pts (70.8%), 54 pts (20.2%) and 24 pts (8.9%) had respectively score 0, 1 and 2, and negative FISH. In luminal tumors these results were respectively 246 (49.3%), 181 (36.3%) and 21 (4.2%). Median age, size of primary tumour and lymph node involvement were similar in both subpopulations. Regarding NAC, 20.9% received only taxanes, 22.1% only anthracyclines and 55.1% both agents. The combination was more often recommended in TNBC 74.2% vs 59.3% (p = 0.03). pCR rate in the primary tumour and lymph nodes was 29% (157 pts) in the whole cohort. This rate varied according to HER2 expression (0, 1+, 2+) from respectively 48.6% (51pts), 36.4% (8pts) and 28.6% (4pts) (p = 0.256) in TNBC and from 8.5% (7pts), 5.3% (5pts) and 4.1% (2pts) (p = 0.532) among luminal tumors. Both OS and RFS were associated with a good Chevalier pathologic response (p < 0.001) in TNBC but not in luminal tumours (p = 0.5257 and p = 0.9845). Neither pCR, nor the Chevalier response was statistically correlated with HER2 score.
Conclusions
No correlation between pCR and the level of HER 2 expression was found neither in luminal nor in TNBC patients. In TNBC patients, differences in terms of pCR were noticed between the 3 HER expression groups. The predictive role of HER2 expression should be further explored in early localized TNBC in a larger population.
Clinical trial identification
Editorial acknowledgement
Isabel Gregoire, medical writer, Department of Biostatistics Georges Francois Leclerc Cancer Center, Dijon, France.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1398 - Phase 1 study of liposomal formulation of eribulin (E7389-LF) in patients (pts) with advanced solid tumors: primary results of dose-escalation part
Presenter: Noboru Yamamoto
Session: Poster Display session 2
Resources:
Abstract
5818 - Polo-like Kinase 1 inhibitor onvansertib synergizes with paclitaxel in breast cancer carrying p53 mutation
Presenter: Antonio Giordano
Session: Poster Display session 2
Resources:
Abstract
5927 - Phase 1b study of heat shock protein 90 inhibitor, onalespib in combination with paclitaxel in patients with advanced, triple negative breast cancer (NCT02474173).
Presenter: Robert Wesolowski
Session: Poster Display session 2
Resources:
Abstract
1695 - Impact of pertuzumab and T-DM1 on prognosis of HER2-positive metastatic breast cancer (MBC) and factors affecting their efficacy: results from the AGMT_MBC-Registry
Presenter: Simon Peter Gampenrieder
Session: Poster Display session 2
Resources:
Abstract
1742 - Clinical profile and outcome of HER2 positive breast cancer patients with brain metastases treated with HER2 targeted therapy: Real world experience.
Presenter: Prabhat Bhargava
Session: Poster Display session 2
Resources:
Abstract
1846 - Pertuzumab, trastuzumab, and docetaxel for HER2-positive metastatic breast cancer: results of single arm phase IV COMACHI study
Presenter: Norikazu Masuda
Session: Poster Display session 2
Resources:
Abstract
5385 - Anti HER-2 Therapies and Left Ventricular Dysfunction The Renaissance Study
Presenter: ANDRES DANIELE
Session: Poster Display session 2
Resources:
Abstract
3320 - Safety and efficacy of T-DM1 in 128 patients with advanced HER2+ breast cancer: The Royal Marsden experience.
Presenter: Nicolò Battisti
Session: Poster Display session 2
Resources:
Abstract
4540 - Use of trastuzumab emtansine (T-DM1; K) after pertuzumab + trastuzumab (PH) in patients with HER2-positive metastatic breast cancer (mBC): challenges in assessing effectiveness of treatment sequencing in the real world (RW)
Presenter: Thibaut Sanglier
Session: Poster Display session 2
Resources:
Abstract
2376 - Patient Reported Outcomes (PRO) in patients (pts) with HER2- advanced breast cancer (ABC) and a germline BRCA1/2 mutation (gBRCAm) receiving talazoparib (TALA) vs physician’s choice chemotherapy (PCT) in the EMBRACA trial: A focus on subgroups with/ without visceral disease
Presenter: Johannes Ettl
Session: Poster Display session 2
Resources:
Abstract