We examined by immunohistochemistry the expression of the bcl-2 protein in sixty-eight cases of operated breast carcinoma patients (stage I, II and III) and correlated the findings with the prognosis. In 38.3% of the cases approximately all neoplastic cells were stained positive (complete expression). A strong impact of complete bcl-2 expression on the clinical outcome was identified (p=0.01). We consider this study as a new approach. There is evidence that the assessment of bcl-2 at the level of complete expression provides important prognostic information for breast carcinoma patients treated surgically. [ABSTRACT FROM AUTHOR]