SERUM LEVELS OF SOLUBLE INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1, CD54) IN PATIENTS WITH NON-SMALL-CELL LUNG-CANCER - CORRELATION WITH HISTOLOGICAL EXPRESSION OF ICAM-1 AND TUMOR STAGE

The expression of the intercellular adhesion molecule-1 (ICAM-1, CD54) seems to have an influence on the metastatic behaviour of tumour cell s via immunological mechanisms. Recently, a soluble form of ICAM-1 was identified in physiological fluids. We analysed the serum levels of s ICAM-1 in patients with non-small-cell lung cancer (NSCLC) and healthy individuals using a sandwich ELISA technique. Sera from 51 patients w ith NSCLC were tested for slCAM-1 (46 male, five female; age 38-81 yea rs, median 64 years), 29 of whom presented with localized and 26 with metastatic disease. The control group consisted of 40 healthy individu als (20 smokers, 20 non-smokers). Immunohistochemical analysis of ICAM -1 in tumour cells was performed in 20 cases. Patients with NSCLC had significantly higher serum levels of sICAM-1 compared with healthy non -smokers (P = 0.00001) and smokers (P = 0.0328). Metastatic disease wa s associated with higher sICAM-1 than localized tumours (P = 0.0013). Only 11 out of 23 patients with localized NSCLC had sICAM-1 levels >30 0 ng ml(-1), compared with 25 out of 28 patients with metastatic disea se. Histological expression of ICAM-1 was positively correlated with s erum slCAM-1 (P = 0.0399). No difference was observed between histolog ical tumour types with regard to slCAM-1 or NSCLC expression of ICAM-1 . In sequential analysis (13 patients), rising sICAM-1 levels predicte d a short-term fatal outcome (P = 0.0054) but, overall, slCAM-1 levels did not correlate with prognosis. In the control group, smokers showe d significantly higher levels than non-smokers (P = 0.0016). In contra st to patients with NSCLC, sICAM-1 in the control group was correlated to the leucocyte count (r = 0.580, P = 0.003). in conclusion, serum l evels of sICAM-1 seem to be associated with tumour burden anti histolo gical expression of ICAM-1 in patients with NSCLC. However, the (patho -) physiological role of ICAM-1 in NSCLC remains to be determined.