The prognostic significance of proliferation-associated nucleolar protein p120 expression in prostate adenocarcinoma - A comparison with cyclins A and B1, Ki-67, proliferating cell nuclear antigen, and p34(cdc2)

BACKGROUND. In this study, the authors evaluated the prognostic significanc e of the expression of nucleolar antigen p120, along with other cell prolif eration-associated proteins, in prostate adenocarcinomas (PACs) and compare d the results with previously reported data on p34(cdc2) cyclin-dependent k inase (p34 cdk). METHODS, Archival sections from 132 PACs were immunostained with monoclonal antibodies against p120, cyclin A, cyclin B1, Ki-67, and proliferating cel l nuclear antigen (PCNA). The DNA content of each tumor was determined by t he Feulgen method using image analysis. The immunohistochemistry (IHC) resu lts were correlated with tumor grade, stage, margin positivity, metastasis, ploidy, and postsurgical disease recurrence. RESULTS, The overall positivity for the various proteins follows: p120, 36% ; cyclin A, 35%; cyclin B1, 43%; Ki-67, 46%; and PCNA, 32%. p120 correlated with grade (P = 0.004), stage (P = 0.01), ploidy (P = 0.02), margin positi vity (P = 0.03), and metastasis (P = 0.004). Cyclin B1 correlated with ploi dy (P = 0.04) and grade (P = 0.05), Ki-6; with grade (P = 0.02) and margins (P = 0.03), and PCNA with grade (P = 0.01). Significant coexpression among these proteins was noted, as was a significant association between the exp ression of these markers and that previously reported for p34 cdk. In univa riate analysis, p120 (P = 0.01), cyclin A (P = 0.01) and p34 cdk (P = 0.002 ) correlated with disease recurrence. In multivariate analysis of all these proteins, only p34 cdk independently predicted postsurgical recurrence (P = 0.05). CONCLUSIONS. Nucleolar antigen p120 expression appears to be an additional marker of aggressiveness in PACs. The significant coexpression of the vario us cell cycle regulatory proteins support their collective role in tumor ce ll proliferation, with p34 cdk positivity being an independent predictor of postsurgical recurrence. (C) 1999 American Cancer Society.