Introduction:

Pathologic overread following transurethral resection of bladder tumor (TURBT) is a common practice at our tertiary care center, however its value in terms of how often management is impacted remains largely unknown. As the treatment of non-muscle invasive bladder cancer (NMIBC) is primarily determined by AUA risk stratification, we sought to determine how pathologic re-review of TURBT performed at an outside institution changed histologic grade, clinical T (cT) stage and risk stratification.

Methods:

A total of 113 patients with <cT2 disease (12 benign, 10 Tis, 46 Ta, 45 T1) and 60 patients with cT2 bladder cancer who underwent TURBT from 2019-2022 were included in this retrospective review. All patients were required to have pathologic re-review of their original outside hospital TURBT specimen initiated by a physician at our institution. Patients were excluded if the original pathology report was not available or if they were missing important clinical characteristics. All pathology slides were re-reviewed by a fellowship-trained, dedicated genitourinary (GU) pathologist. Risk stratification categories were assigned according to the AUA Guidelines for Diagnosis and Treatment of NMIBC (2020). Clinical data was obtained from chart review of the electronic medical records. Descriptive statistics were performed on the final dataset.

Results:

For the entire <cT2 cohort, upgrading was observed in 12/113 (10.6%), downgrading in 8/113 (7.1%), and no change in grade in 93/113 (82.3%). Increased clinical stage was demonstrated in 6/113 (5.3%), decreased stage in 6/113 (5.3%) and no change in stage in 101/113 (89.4%).  For patients with cT2 disease, grade did not change in any cases, none were upstaged and 3/60 (5.0%) were downstaged. Of patients with <cT2 disease, 15/112 (13.4%) experienced increased and 9/112 (8.0%) experienced decreased risk stratification. No cases with change in NMIBC risk stratification were initially reviewed by a fellowship-trained GU pathologist. The most important contributor to change in risk was grade, which led to increased risk in 11/15 (73.3%) and decreased risk in 8/9 (88.9%) of cases. Addition of variant histology on re-review only led to increased risk stratification in 3/15 cases. Interestingly, four cases were changed from high-risk to benign on pathologic re-review.

Conclusion:

Re-review of pathologic slides by a dedicated GU pathologist following TURBT led to change in AUA NMIBC risk stratification in over one-fifth of patients, with potential for changing management in all of these. Therefore, this is an important option that should be considered for patients with bladder cancer. This study was limited by lack of operative reports from outside hospitals precluding ability to fully risk stratify patients using multifocality and tumor size, although these particular aspects would not be impacted by pathologic over-read.

Funding: N/A