The influence of review pathology on study outcome of a randomized multicentre superficial bladder cancer trial. Members of the Dutch South East Cooperative Urological Group.

OBJECTIVE To determine whether differences between local and review pathology in a multicentre study influence the results of treatment and results from prognostic factor analysis. PATIENTS AND METHODS A randomized multicentre study in superficial bladder cancer is reported, in which the influence of local and review pathology on the study outcome was investigated. RESULTS The conformity between local and review pathology of the pT category was 79.3%, of the grade 70.2%, and the combination of both 59.7%. In local pathology, undergrading was more frequent than overgrading and overstaging more frequent than understaging. However, the risks of recurrent disease in the separate stage and grade groups remained the same after correcting the pathology result. A prognostic factor analysis with regard to the risk of recurrent disease was carried out. The Cox hazard ratios of tumour localization, multiplicity, patient age (significant factors), tumour grade, size, history and gender (not significant) remained almost the same after correction for review pathology. Only the prognostic relevance of tumour stage increased after pathology correction. CONCLUSION We conclude that, although review pathology caused considerable changes in the pathology results, this did not change the results of treatment, and hardly altered the results of a prognostic factor analysis in this randomized study.