OBJECTIVE: The drug resistance at cellular level is mediated by P-glycoprotein (P-G), which is variably expressed in bladder tumours. The effect of intravesical chemotherapy on P-G status was studied in chemoresistant and recurrent superficial tumours which progressed to metastasis or needed further treatment. METHODS: Archival histological materials of 14 patients who received intravesical epirubicin for recurrent superficial transitional cell carcinoma of the bladder were studied for the presence of P-G using monoclonal antibody JSB-1. RESULTS: Four patients showed complete absence of P-G following chemotherapy although only 2 patients were recurrence-free. In 4 patients with extravesical metastasis, there was no evidence of increased P-G expression. CONCLUSIONS: The P-glycoprotein expression is not related to histological grading or clinical progression of bladder tumours.
OBJECTIVE: The drug resistance at cellular level is mediated by P-glycoprotein (P-G), which is variably expressed in bladder tumours. The effect of intravesical chemotherapy on P-G status was studied in chemoresistant and recurrent superficial tumours which progressed to metastasis or needed further treatment. METHODS: Archival histological materials of 14 patients who received intravesical epirubicin for recurrent superficial transitional cell carcinoma of the bladder were studied for the presence of P-G using monoclonal antibody JSB-1. RESULTS: Four patients showed complete absence of P-G following chemotherapy although only 2 patients were recurrence-free. In 4 patients with extravesical metastasis, there was no evidence of increased P-G expression. CONCLUSIONS: The P-glycoprotein expression is not related to histological grading or clinical progression of bladder tumours.