Aims: Activated leukocyte cell adhesion molecule (ALCAM) is a cell surface immunoglobulin expressed in breast cancer (BC) and is assumed to be implicated in tumourigenesis and tumour progression. The importance of the adhesion molecule ALCAM for the response to taxane-free adjuvant chemotherapy was investigated.
Materials and methods: Tissue specimens from 162 primary breast cancer patients were analyzed. Immunohistochemical staining (IHC) and Western blots (WB) were performed using monoclonal antibody against ALCAM. Relative protein amounts in WB bands were determined densitometrically. ALCAM mRNA expression was evaluated by microarray analysis (Affymetrix).
Results: In the normal breast ALCAM is expressed in luminal and basal epithelial cells. In BC samples, WB analysis showed a significant positive correlation of ALCAM levels with estrogen receptor status (p=0.04). For patients who received a taxane-free chemotherapy, a high ALCAM expression was predictive for a good response to chemotherapy. Median mRNA expression of ALCAM was 4.5-fold higher in patients alive at the time of follow-up compared to those who died of breast cancer.
Conclusions: Higher ALCAM expression showed a positive correlation with estrogen receptor status and is a useful predictive marker for the response to taxane-free chemotherapy.