32P - Biomarkers and molecular subtypes in primary breast tumors and metastases: associations with liver metastases and outcome

Date 08 May 2014
Event IMPAKT 2014
Session Welcome reception and Poster Walk
Topics Breast Cancer, Metastatic
Pathology/Molecular Biology
Presenter Siker Kimbung
Citation Annals of Oncology (2014) 25 (suppl_1): i8-i16. 10.1093/annonc/mdu066
Authors S. Kimbung1, A. Kovács2, I. Johansson1, A. Danielsson3, P. Bendahl1, Z. Einbeigi3, M. Ferno1, T. Hatschek4, I. Hedenfalk1
  • 1Division Of Oncology, Department Of Clinical Sciences, Lund, Lund University, 22381 - Lund/SE
  • 2Department Of Clinical Pathology And Cytology, Sahlgrenska University Hospital, Gothenburg/SE
  • 3Department Of Oncology, Institute Of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg/SE
  • 4Dept. Of Oncology, Breast-sarcoma Unit, Karolinska University Hospital and Karolinska Institutet, 171 76 - Stockholm/SE

Abstract

Although discordant expression of biomarkers between a primary tumor and metastasis may significantly alter disease biology, personalization of therapy and prognosis after recurrence is mainly determined based on the primary tumor biomarker status. This study aimed to evaluate the prognostic relevance of metastasis-specific biomarkers and identify an estrogen receptor (ER) positive liver metastasis-specific gene signature. A cohort of 304 women with locally advanced and metastatic breast cancer was studied. ER, progesterone receptor (PR), HER2 and Ki67 expression were quantified in primary tumors (N217) by immunohistochemistry and in situ hybridization on tissue microarrays, and molecular subtypes were assigned according to the St Gallen guidelines 2013. In addition, fine-needle aspirates of metastases (N91) were transcriptionally profiled and intrinsic subtypes were determined using the PAM50 classifier. Overall, the expression of biomarkers and molecular subtypes was stable during tumor progression. However, amongst discordant cases, loss of expression at recurrence was significantly observed for ER [81 (17/21), P0.007] and PR [78 (32/41), P