247O_PR - The discrepancy between high pathological complete response (pCR) rate and low breast conserving surgery (BCS) following neoadjuvant therapy: analys...

Date 30 September 2012
Event ESMO Congress 2012
Session Breast cancer, early stage
Topics Breast Cancer, Early Stage
Pathology/Molecular Biology
Presenter Carmen Criscitiello
Authors C. Criscitiello1, H.A. Azim Jr.2, D. Agbor-Tarh3, E. De Azambuja4, M. Piccart5, J. Baselga6, H. Eidtmann7, S. Di Cosimo8, I. Bradbury3, I.T. Rubio9
  • 1Department Of Medicine, European Institute of Oncology, 20141 - Milano/IT
  • 2Breast Cancer Translational Research Laboratory, Institute Jules Bordet, 1000 - Brussels/BE
  • 3Frontier Science, Frontier Science, Kincraig/UK
  • 4Medical Oncology, Institute Jules Bordet, BE-1000 - Brussels/BE
  • 5Medicine, Institut Jules Bordet, Brussels/BE
  • 6Hematology/oncology, MGH Cancer Center, Massachusetts General Hospital, MA 02114 - Boston/US
  • 7Klinik Für Gynäkologie Und Geburtshilfe, Universitäts Frauenklinik Kiel, Kiel/DE
  • 8Medical Oncology, Istituto Nazionale Tumori, Milan/IT
  • 9Department Of Gynecology, Hospital Universitario Vall d'Hebron, Barcelona/ES

Abstract

Background: The NeoALTTO trial showed that paclitaxel plus lapatinib and trastuzumab nearly doubles the rate of pCR compared to paclitaxel combined with either drug alone (51.3% vs 29.5% vs 24.7%). However, this high pCR rate did not translate into a higher rate of BCS, which was around 40% across the 3 arms. We investigated different factors that may have affected the choice of surgery.

Patients and Methods: In the NeoALTTO trial, patients (pts) with HER2+ breast cancer were randomized to either trastuzumab, lapatinib or their combination concomitantly with paclitaxel prior to surgery. The 1ry endpoint was pCR, defined as the absence of invasive cancer in the breast at the time of surgery. Here, we investigated the association between achieving pCR, and type of surgery, age, histology, grade, tumor size, ER status, multicentricity, response to therapy and the country where the treatment was given.

Results: 429 pts were eligible for the analysis (26 have been excluded as they did not undergo breast surgery), of whom 160 (37%) achieved a pCR. 242 (57%) and 187 (43%) pts had mastectomy and BCS, respectively. Mastectomy was more frequent if the patient was < 50, if treated in developing country, if the tumor was multicentric, >5 cm, or ER-. All pts diagnosed with lobular cancer (n=17) underwent mastectomy regardless of pCR. 68 pts had a radiological complete response, yet 36 of those (53%) were subjected to mastectomy (25 pts (70%) achieved a pCR). Of the 128 pts considered for BCS at screening, only 95 (74%) had a conservative surgery and rates were similar according to pCR status (79% in pCR vs. 72% in no pCR). Conversely, 30% of pts initially evaluated as inoperable or requiring mastectomy had a BCS.

Conclusion: Tumor characteristics prior to neoadjuvant therapy appeared to play a main role in deciding the type of surgery irrespective of response. This may deny a large fraction of women the chance of preserving their breast. These results should be taken into account in addressing the criteria for BCS after neoadjuvant therapy.

GSK distributed the study drugs and provided financial support to the NeoALTTO trial, but imposed no restriction to the current analysis