Role of P-glycoprotein in chemoresistant superficial 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.