EXPRESSION OF BCL-2 PROTEIN IN NEPHROBLASTOMAS

Bcl-2 expression has been shown to relate to prognosis in several neop lasms. A study of 139 cases of nephroblastomas was undertaken to ascer tain the prognostic value of bcl-2 immunoexpression. Archival formalin -fixed, paraffin-embedded tissue sections were stained with monoclonal anti-bcl-2 antibody using a peroxidase-labelled streptavidin biotin k it. 75.5% of cases showed bcl-2 immunoreactivity, however, heterogeneo us staining was observed within each case. No statistically significan t correlation was found when bcl-2 expression was compared to histolog y (P=0.451), disease status (P=0.375) and disease stage (P=0.875). A s tatistically significant difference in bcl-2 protein was noted when co mparing tumours treated with and those not treated with pre-operative chemotherapy (P=0.002). Further analysis of the cases that were treate d with pre-operative chemotherapy showed a striking difference in surv ival periods between bcl-2 positive (shorter) and negative tumours (lo nger). Although not statistically significant, we think that this find ing requires further investigation in other series. The results of bcl -2 immunoexpression in nephroblastomas may have prognostic implication s that impact on patient treatment protocols.