Markers of the uPA system and common prognostic factors in breast cancer

The urokinase plasminogen activator (uPA) system includes uPA and plasminogen activator inhibitor types 1 (PAI-1) and 2 that mainly act by regulating extracellular matrix degradation, and it is involved in tumor progression. The -675 4G/5G polymorphism of the PAI-1 gene regulates PAI-1 activity in serum. We aimed at studying the -675 4G15G polymorphism of the PAI-1 gene and uPA, PAI-1, and cyclooxygenase-2 (COX-2) immunohistochemical expression in a series of breast cancer cases. Homozygosity for the 4G allele of the PAI-1 gene was associated with node-positive breast cancer (P =.02). We showed a direct correlation between uPA and estrogen receptor expression (P.03); negative uPA expression was associated with negative hormonal expression, high tumor grade, and high proliferation index (P <.05). A direct correlation was seen between uPA and PAI-1, uPA and COX-2, and PAI- I and COX-2 expression (P <.05). Interaction between uPA and COX-2 systems in breast cancer deservesfurther study.