Review pathology in a diagnostic bladder cancer trial: effect of patient risk category

Bladder cancer pathologic features are a continuous spectrum from benign to invasive lesions, causing diagnostic difficulties. Review pathology might be an answer, but appears to be of limited value. We studied the effect of patients' risk profile on the value of review pathology.

We used three Phase III multicenter studies that assessed the value of hexaminolevulinate fluorescence cystoscopy on diagnosis and management. Two studies (Europe and United States) included patients at high risk of carcinoma in situ (CIS), the third study (Europe) included all patients at risk of bladder cancer. Tumors and biopsies were examined by a local and review pathologist.

The percentage of patients with CIS was high in the first two studies (20.6% and 15.9%) compared with the epidemiologic data (7.9%) and the third study (7.8%). The numbers of patients (specimens) in the three studies were 209 (927), 277 (986), and 142 (553). Overall conformity for both grade and stage was between 50.5% and 56.6%, comparable to published data. Although conformity was best in the high-risk study, this was predominantly because of the better conformity in low-risk tumors. Conformity in Stage T1, CIS, and invasive tumors was low. The results from Europe and the United States were comparable, although the local pathologist in the United States tended to overstage or overgrade.

Although histologic conformity was greater in the high-risk patient population, this was mainly a result of pTa tumors. The diagnosis of pT1, CIS, and invasiveness appears difficult. Because these tumors significantly influence therapy, review pathology in patients at high risk or suspicious for high risk should be considered.