12P - Evaluation of changes in the HR status and Her2 expression following neoadjuvant chemotherapy.

Date 04 May 2017
Event IMPAKT 2017
Session Welcome reception and Poster Walk
Topics Cytotoxic agents
Breast Cancer
Therapy
Biological therapy
Presenter Carolina Ponce
Authors C.R. Ponce1, F.A. Colo1, M. Maino1, V.Y. Fabiano1, C.M. Loza1, M. Amat2, A. Nervo3, V. Costanzo3, J.B. Loza1, R. Chacon3
  • 1Patología Mamaria, Instituto Alexander Fleming, C1426ANZ - Ciudad Autónoma de Buenos Aires/AR
  • 2Patología, Instituto Alexander Fleming, C1426ANZ - Ciudad Autónoma de Buenos Aires/AR
  • 3Oncología, Instituto Alexander Fleming, C1426ANZ - Ciudad Autónoma de Buenos Aires/AR

Abstract

Body

Objective: The hormone receptor and HER2 expression of a primary breast carcinoma plays a significant role in patient management, treatment and prognosis. The aim of this study was to compare immunohistochemical (IHC) profiles of primary breast carcinomas before and after neoadjuvant chemotherapy (NAC) to assess the subsequent effects on hormone receptor and Her2 status.

Methods: Retrospective analysis of 85 breast cancer patients surgically treated from March 2010 to December 2016 at our institute, who underwent NAC. Results obtained from core biopsy before treatment were compared with results obtained from surgical specimen after treatment. All the specimens were subjected to histological study and IHC for HR and HER2 status (FISH when IHC was 2+)

Results: Mean age was 47 years (range: 27-69) and 58% were premenopausal. The histologic type was invasive ductal carcinoma in 83,52% (n=71). 27,05% (n=23) had Luminal A tumors; 9,4% (n=8) Luminal B; 14,1% (n=12) Luminal B Her+; 18,8% (n=16) Her2+ and 30,5% (n=26) triple-negative. Pathologic complete response (pCR) rate was 30,5% (n=26). pCR was achieved in 30,7% (n=8) of triple-negative tumors; 8,6% (n=2) of luminal A tumors; 37,5% (n=3) of luminal B; 25% (n=3) of luminal B Her2+ and 56,25% (n=9) of Her2+ tumors. For the analysis of changes on biological markers, all the 26 patients with pCR and other 6 patients without complete data were excluded. Among 14 patients who were HER2positive before treatment, 7 had HER2negative tumors after NAC, whereas 4 of the 39 patients with HER2-negative tumors before treatment had HER2-positive tumors afterward. Out of 32 patients with ER-positive tumors before treatment, 1 had ER-negative tumors after NAC, whereas 9 of the 21 patients who were ER-negative before treatment had ER-positive tumors afterward.

Conclusions: Changes, like those seen in our study, have been previously reported. We consider HER2 status as well as hormone receptors should be reevaluated post NAC, since changes can be observed in order to accurately determine appropriate use of targeted therapy. The clinical relevance of these changes and the implications for subsequent adjuvant systemic therapy requires further long-term follow-up

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