Prognostic Significance of PCNA Index and AgNORs Score in Transitional Cell Carcinoma of the Renal Pelvis

ABSTRACT

Proliferative activity of a malignant tumor is known to reflect its biological aggressiveness. Proliferating cell nuclear antigen (PCNA) is a marker of cellular proliferation, and silver-stained nucleolar organizer regions (AgNORs) have been shown to correlate with ploidy and proliferative activity of cells. In transitional cell carcinoma of the renal pelvis, the prognostic value of these markers has not been well defined. We studied PCNA expression and the AgNORs count in 22 transitional cell carcinoma of the renal pelvis to assess their prognostic significance compared with their cumulative survival rate, the stage of disease and histopathologic features of the tumors. An immunohistochemical method and a standard colloidal silver staining were used. The mean percentage of PCNA positivity (PCNA index) and the mean number of AgNORs per nucleus (AgNORs score) were determined. In a multivariable analysis, PCNA indexes were significantly associated with tumor stage (p=0.024), whereas AgNORs scores were not significantly associated with the stage or histopatholgic features of the tumors. Histologic grade was correlated to disease stage at a significant level (p=0.000). But there was a trend of low tumor PCNA-indices or AgNORs counts with survival advantage for patients, but this did not reach statistical significance. The results suggest that the fraction of PCNA positive nuclei would be useful for investigating the malignant potential of renal pelvic cancers, although their clinical use as markers of biologic behavior may be limited.