The role and impact of pathology review on stage and grade assessment of stages Ta and T1 bladder tumors: A combined analysis of 5 European organization for research and treatment of cancer trials

Purpose: Pathological interpretations are largely subject to interpathologist and intrapathologist variation. Differences in tumor stage and grade exist in local and review pathological findings in patients with stage Ta-T1 bladder tumors who are entered in randomized trials of adjuvant treatment after transurethral resection. Because they are diagnosed and treated based on local pathological results, it is important to determine the reliability of local pathological evaluations and the extent to which pathology review may change the treatment decision process. Materials and Methods: We assessed local and review pathology results in 1,400 patients treated in 5 European Organization for Research and Treatment of Cancer randomized phase III trials comparing various adjuvant prophylactic treatment strategies for primary or recurrent stage Ta-T1 transitional cell bladder cancer. Results: We noted large variations in T category and grade. Pathology review down staged T category to stage Ta in 53% of eases originally classified as stage TI. There was agreement in only 57% and 50% of stage Ta grade 1 and stage T1 grade 3 cases, of which 10% were reclassified as muscle invasive disease greater than stage T1. While T category and grade have prognostic importance, differences in the prognosis based on local and review pathological studies were slight. Conclusions: Pathology review is not mandatory in low and intermediate risk cases since it has little impact on the prognosis and treatment decision making. In high risk cases of stage T1 grade 3 disease stage or grade is often changed, so that review remains essential in this subgroup.