TP53 accumulation predicts improved survival in patients resistant to systemic cisplatin-based chemotherapy for muscle-invasive bladder cancer.
Qureshi KN., Griffiths TR., Robinson MC., Marsh C., Roberts JT., Hall RR., Lunec J., Neal DE.
To examine retrospectively the prognostic significance of TP53 immunoreactivity for both tumor response and patient survival in 83 patients with nonmetastatic muscle-invasive bladder cancer treated with a single transurethral resection (TUR) of tumor and combined cisplatin-based systemic chemotherapy followed by repeat TUR, paraffin-embedded sections of a bladder tumor obtained at TUR before chemotherapy (1 T2, 52 T3, and 30 T4) were immunostained for TP53 using monoclonal PAb1801 and DO-7 antibodies. For the entire cohort, TP53 immunopositivity (PAb1801 or DO-7) did not predict complete response (CR), complete or partial response (PR), progressive disease, or time to death from bladder cancer. There was a highly significant correlation between PAb1801 and DO-7 nuclear immunoreactivity (r = 0.8242; P<0.0001). In 76 patients in which complete clinical data were available, tumor stage (T2/T3; P = 0.0499), CR and PR (P = 0.0016) and CR (P<0.0001) were associated with patient survival. In a multivariate model, CR (P<0.0001) was the only independent predictor of improved survival. In complete responders, neither TP53 immunostaining nor clinicopathological factors stratified patients into prognostic groups. However, in the subset of patients (n = 38) who were chemoresistant (PR or progressive disease), improved survival was associated with > or =20% TP53 immunoreactivity (PAb1801; P = 0.0191) and tumor stage (T2/T3; P = 0.0358). TP53 immunopositivity (PAb1801 or DO-7) did not predict overall survival or response to systemic chemotherapy in patients with nonmetastatic but predominantly clinical stage > or =T3 bladder cancer, but it had prognostic significance within the chemoresistant subgroup.