Comparison between Steroid Receptors and Her2 Status in Primary Breast Carcinoma and Completely Resected Breast Carcinoma Metastases from Different Visceral Organ Sites.

Abstract

Abstract Background: Metastases biopsy are seldom performed in metastatic breast carcinoma (MBC) and hormonal, and anti-Her2 therapy are given upon biological markers of the primary breast cancer (PBC).However, there are reports about discrepancies in biological markers between PBC and MBC that could significantly influence treatment outcome.Aim: The aim of this paper is to compare steroid receptors and Her2 status of the PBC and of resected metastases (MBC) Patients and methods: Pathology reports were analyzed for all patients who underwent resection of PBC and resection of liver, brain or lung metastases. Rationale for this patients selection is the assumption that BC, as a heterogeneous malignancy might have differently expressed biological markers in different parts of metastases and therefore, biopsy only might not be completely informative about biological marker status of MBC. Results: 36 pts were identified: 27 with liver metastasis resection; 8 with brain metastasis resection; and 1 patient with lung metastasis resection. Median age was 51,5 years (31-73) Median DFI was 36 months (0-144) ER/PGR status of PBC was known for 32/36 pts and for 30/36 pts in metastasis (MBC). HER2 status of PBC was known for 30/36 pts and for 29/36 in MBC. To facilitate results interpretation, steroid receptor status is divided in 2 groups upon indication for hormonal treatment: A. hormone dependent, (one or both receptors score ≥ 4): B. hormone independent, (both receptors ≤ score 3). Her2 status is also divided in 2 groups upon indication for trastuzumab as: C. Her2 negative if IHC Her 2 was 0+,1+, or 2 + D. Her2 positive, if IHC was 3+ or CISH +; E. Triple negative if both steroid receptors were score 0 and Her2 0+ Results are presented at table 1.ResultsInitial biological markers status in PBCNo of pts (%)Changed biological markers status in MBC (%)CommentA. ER or PGR ≥ 421 (65,6%)12 (57%)12/21 (57%) hormone dependent PBC become hormone independent in MBCB.ER and PGR ≤ 311 (34,3%)1 (9 %)1/11 (9%) hormone independent PBC become hormone dependent in MBCC. Her2 0+,1+,2+24 (80%)0 (0%)0/24 (0%) Her2 0+,1+,2+ PBC has changed status to Her2 3+ in MBCD.Her2 3+6 (20%)1 (16,6%)1/6 (16,6%) Her2 3+ PBC has changed status in Her2 1+ in MBCE.Triple negative3 (10%)0 (0%)0/3 (0%) triple negative PBC has changed status in MBC Conclusion: Biological markers, that are considered as poor prognostic factors are more stable characteristics of BC hence they tends to change in MBC in much lesser degree than biological markers that are considered as good prognostic factors. Although obtained in selected subgroup of BC patients who developed resectable BC metastases, these results could be implemented in every day clinical practice, hence triple negative, steroid receptor negative and Her2 positive PBC almost always retains these characteristics in MBC. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4048.