Comparison of Predictive Immunohistochemical Marker Expression of Primary Breast Cancer and Paired Distant Metastasis using Surgical Material: A Practice-Based Study.

Parallel studies of primary breast carcinomas and corresponding distant metastases samples reveal considerable differences. Our aim was to highlight this issue from another perspective and provide further data based on 98 patient samples: 69 primary breast carcinoma and 85 distant metastases from bone, central nervous system (CNS) and lung (56 paired). Two independent series of immunohistochemical reactions with different antibodies for estrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (Her2), along with HER2 fluroscence in situ hybridization (FISH) were performed on tissue microarrays to classify breast carcinoma and distant metastases samples into Luminal A, Luminal B-proliferating, Luminal B-HER2+, HER2+ and triple negative (TNBC) surrogate breast cancer groups. Correlation and agreement between the two assessments of ER and PgR were fair-to-moderate, and almost perfect for HER2 and Ki67. There was 40% discordance concerning immunophenotype between breast carcinomas and distant metastases. Most common metastatic site of ER+ breast carcinoma was the skeletal system (59.2%), whereas that of TNBCs was the CNS (58.8%) and lungs (23.5%). Distant metastases in bones were mostly luminal (54.3%), in the CNS, Luminal B (53.2%), and in the lung, TNBC (37.5%). The change of drugable properties of primary breast cancers in the respective bone and CNS metastases suggests that characterization of the metastasis is necessary for appropriate treatment planning.

Expression of proliferation markers Ki67, cyclin A, geminin and aurora-kinase A in primary breast carcinomas and corresponding distant metastases.

AIMS: To assess the expression of the following cell cycle regulatory proteins in primary metastatic breast carcinomas (MBCs) and on availability in matched distant metastases (DMs): Ki67, cyclin A, geminin and aurora-kinase A (aurkA); and to compare the expression of these markers in early MBC (EMBC) and late MBC separated into groups according to median time point on metastatic event occurred (28 months). METHODS: The expression of the above mentioned markers was analysed in a total of 47 primary MBCs and 59 DMs (out of which 37 were pairs) by immunohistochemistry. Fourteen breast carcinomas with no relapse over a 10-year follow-up period were utilised as control cases (CBC). RESULTS: Among the MBCs, 22 metastasised to the bone, 4 to the lung and 21 to the central nervous system (CNS). Geminin (p<0.001) and Ki67 (p=0.001) were increased in the MBCs while aurkA and cyclin A showed no difference when compared with CBCs. There were no differences between aurkA, cyclin A and geminin expression in MBCs and DMs in general. Expression of Ki67 was, however, elevated (p=0.027) in DMs. In CNS metastases all markers showed elevated expression as compared to MBCs. In bone metastases, geminin was lower (p<0.001) compared with primary MBCs. In the metastases of the lung, the evaluated markers did not show different expression. According to the median follow-up until the metastatic event, Ki67 was found to be significantly elevated in EMBC (p=0.018). CONCLUSIONS: Ki67 index and geminin distinguish a fraction of MBC with worse prognosis, showing increased levels in the latter in comparison to CBC being tumour-free over a 10-year follow-up period. Ki67 could possibly identify a group of MBCs that develop early DMs.