Serum c-erbB-2 levels in monitoring of operable breast cancer patients

Background: Various methods and criteria are used to determine protein over expression of c-erbB-2 and the clinical utility of c-erbB-2! is under inves tigation. We have reported previously that the levels of cytosol c-erbB-2 i n breast cancer were significantly different between the clinical stages, Methods: The levels of c-erbB-2 protein were determined in sera from 210 br east cancer patients using a sandwich enzyme immunoassay between November 1 996 and March 1998, The cut-off level was set at 5.4 ng/ml for healthy fema le blood donors. Results: First, serum c-erbB-2 levels were analyzed in 73 preoperative brea st cancer patients with stage I-IIIB disease. The range and median values w ere 2.3-32.3 and 4.8 ng/ml, respectively The positive rate was 38%, Overexp ression of serum c-erbB-2 was significantly associated with tumor size, cli nical stage, histological grade, lymphatic invasion, nodal status and overe xpression of cytosol c-erbB-2, but not with hormonal receptor status and ot her clinico-pathological factors. Second, c-erbB-2, CEA and CA15-3 in sera were examined in 157 postoperative breast cancer patients. in the 137 disea se-free patients,specificities of c-erbB-2, CEA and CA153 were 72, 93 and 9 9%, respectively, but in the 20 first recurrent patients, these sensitiviti es were 80, 25 and 25%, respectively Conclusions: These results suggest that serum c-erbB-2 protein is a useful marker for predicting aggressive behavior and first recurrence of breast ca ncer.