c-erbB 2 Serum level as prognostic factor in hormonally treated advanced breast cancer patients

To investigate whether c-erbB 2 serum levels may be predictive of clinical response, progression-free and overall survival in postmenopausal women with advanced breast cancer hormonally treated, 265 patients enrolled in previous clinical trials were evaluated. C-erbB 2 serum levels were assessed before the start of treatment and in a subgroup of patients also at the first response evaluation. In addition, serum CA 15.3 levels were determined. The role of c-erbB 2 was investigated by means of multiple regression models in which both c-erbB 2 and CA 15.3 values were modelled as continuous variables together with other known prognostic factors. The failure probability tended to be higher in the presence of high c-erbB 2 levels, but the trend was not statistically significant; in contrast, significant results were obtained for progression-free survival (PFS,P <0.001) and overall survival (OS, P=0.014). The within-patient c-erbB 2 variation significantly predicted PFS (P=0.006) and OS (P=0.040). It is worth noting that c-erbB 2 and CA 15.3 baseline levels were significantly correlated and that the prognostic effect of c-erbB 2 tended to disappear in the presence of high CA 15.3 levels for PFS and OS.