Expression and prognostic value of proliferating cell nuclear antigen in transitional cell carcinoma of the urinary bladder.

Forty-eight patients with transitional cell carcinima (TCC) of the bladder were investigated. Routine paraffin-embedded sections were stained with proliferating cell nuclear antigen (PCNA) monoclonal antibody in order to determine the growth fraction of the bladder tumors and to correlate this with tumor grade, stage, development of recurrence and survival rate during follow-up. PCNA positive staining was detected in 95.8% (46/48) of the tumors. The mean labeling index (LI) of superficial tumors (Ta-1, n = 28) was 12.58 +/- 12.33%, and 34.55 +/- 21.89% in invasive tumors (T2-4, n = 18). A similar correlation was found in association with tumor grade. The patients were followed up for a mean of 4.9 years (range 1-14 years). The mean PCNA LI in nonrecurrent (n = 21) and simple recurrent (n = 7) superficial tumors was 11.29 +/- 11.79% and 16.44 +/- 14.05%, respectively, the difference not being statistically significant. To access survival, tumors with a PCNA LI above and below the median level (21%) were compared. Those patients (n = 19) with an index of > 21% (the mean of all the PCNA values) had a worse prognosis than those (n = 27) with an index of < 21%, a difference which is statistically significant. These results suggest that PCNA LI in bladder cancer may prove to be an objective and quantitative assay of biological aggressiveness and provide significant prognostic information, although it does not help the selection of patients at risk of simple recurrence in superficial tumors.