Prognostic value of uPA, PAI-1 and PAI-2 mRNA expression in primary breast cancer

Background: The prognostic value of uPA, PAP 1 and PAI-2 mRNA expression was studied in a retrospective series of 130 primary breast cancer patients (median follow-up 8.1 years). Materials and Methods: UPA, PAI-1 and PAI-2 mRNA were quantified by means of real-time quantitative RT-PCR. Comparison with the corresponding protein levels determined by ELISA was performed in 21 cases. Results: Higher uPA protein values were found in cases with high mRNA values, but the relationship was of borderline significance. PAPI and PAI-2 mRNA were positively correlated to protein values. The mRNA expression of uPA, PAI-1 and PAI-2 was significantly correlated with one another. Higher uPA and PAI-1 mRNA values were significantly associated with shorter disease-free survival (DFS) (p=0.002; p=0.03, respectively). Low and very high PAI-2 mRNA values tended to be associated with longer DFS. In Cox multivariate analyses, higher uPA and PAI-1 mRNA values were independently associated with shorter DFS. PAI-2 was not retained as a significant variable in the Cox model. Conclusion: These preliminary results indicate that, in breast cancer, uPA, PAI-1 and PAI-2 mRNA analysis by quantitative RT-PCR give results comparable to those obtained at the protein level.