Background. Serum levels of some soluble adhesion molecules (e.g. ICAM-1, or E-selectin) are higher in some patients with breast cancer (especially metastatic) compared to controls. They bring about the increased risk of developing metastases and they can negatively influence the prognosis of patients. The aim of our study was to assess the serumlevels of several soluble adhesionmolecules (soluble E-selectin, P-selectin, ICAM-1,VCAM-1 andCD44s) in patients with breast cancer in clinical stage 0-IV before the beginning of hormonal therapy and/or chemotherapy. We wanted to find out if these parameters differ between various stages of breast cancer and if their levels are influenced by the therapy. Methods and Results. We examined 59 mostly postmenopausal patients with breast cancer in clinical stage 0-IV (mean age was 62 years). One patient was in stage 0, 10 patients were in stage I, 24 patients were in stage IIA, 11 patients were in stage IIB, 5 patients were in stage III and 8 patients were in stage IV. Serum levels of soluble E-selectin, P-selectin, ICAM-1, VCAM-1 and standard form of CD44 were assessed using ELISA in sera of patients with breast cancer before the institution of hormonal therapy and/or chemotherapy and 3 and 12 months after the beginning of therapy. Compared to controls, patients with (metastatic and also non-metastatic) breast cancer before the beginning of therapy had higher serum levels of soluble E-selectin, P-selectin, ICAM-1 and standard form of CD44. Serum levels of E-selectin, ICAM-1 and also VCAM-1 significantly decreased one year after the beginning of therapy. Serum levels of soluble adhesion molecules mutually correlated and they also correlated with serum levels of soluble TNF and IL-2 receptors and some acute phase proteins (CRP and orosomucoid). Conclusions. Serum levels of some soluble adhesion molecules (E-selectin, P-selectin, ICAM-1 and CD44s) were higher in some patients with breast cancer and decreased again after hormonal therapy and/or chemotherapy. Only larger studies with longer follow-up may imply if any of these parameters (e.g. soluble P-selectin), or their combination may become useful marker of activity and/or outcome.

        Key words: breast cancer, adhesion molecules, E-selectin, P-selectin, ICAM-1, VCAM-1, CD44.