Affiliations: Department of Gynecology, University Medical Center
Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany | Institute for Pathology, University Hospital of Basel,
Schönbeinstrasse 40, 4031 Basel, Switzerland | Department of Statistics and Epidemiology, University
Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany
Note: [] Corresponding author: M. Ihnen MD, Department of Gynecology,
University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg,
Germany. Tel.: +49 1799153286; Fax: +49 40 7410 54355; E-mail:
m.ihnen@uke.uni-hamburg.de
Abstract: Introduction: Activated Leukocyte Cell Adhesion Molecule
(ALCAM/CD166) gained increasing attention regarding tumorprogression and
metastatic spread in breast cancer. The aim of this study was to examine ALCAM
expression levels in primary breast cancer and distant metastases of the same
patient within 29 autopsy cases to better understand the underlying mechanisms
of metastases and the role of adhesion molecules in this process. Material and Methods: Paraffin-embedded tissue of the primary and distant metastases (N=84)
were collected and ALCAM immunohistochemistry was performed. Results: The primary tumor and all metastases showed a statistically normally
distributed ALCAM expression. ALCAM expression level average differs between
immunoreactive score (IRS) (mean) 4.16 (lung)-5.00 (adrenal gland). Of the
metastatic ALCAM expression levels we obtained an intra-class correlation (ICC)
of 80.9%, indicating a strong cluster effect of measurements in the same
patient. ALCAM expression scores in metastatic sites and in the primary
analyzed by hierarchical regression analysis showed that ALCAM expression in
the primary is prognostic for ALCAM expression in all different sites of
metastases (slope=0.773, p < 0.001, r^{2}= 0.504). Conclusion: ALCAM expression in the primary is positively correlated to ALCAM expression in
metastases within one single patient. This could show a tumorbiological context
of ALCAM for the development of metastases in breast cancer.
Keywords: Adhesion molecules, ALCAM, breast cancer, distant metastasis, metastasis development
