Prognostic significance of tissue-type plasminogen activator (tPA) content in gastric cancer and surrounding mucosa

We analyzed the tPA content in primary gastric carcinomas and surrounding mucosa in order to assess the relationship between tPA content, clinicopathological tumor characteristics, and estrogen and progesterone receptor content. We evaluated the prognostic value of this serine protease in gastric cancer patients. 122 resected gastric neoplasms and 95 adjacent mucosa samples were studied. The tPA content was measured in cytosol by an ELISA method. Cytosolic ER and PgR were measured with a solid phase enzyme immunoassay. Cytosolic tPA levels in neoplastic tissues (median 1.0 ng/mg prot) were significantly lower (p=0.002) than those found in paired mucosa samples (median 2.3 ng/mg prot). There was no significant association between tPA levels and clinicopathological parameters or PgR content, but tPA levels were significantly correlated with ER content. The intermediate-tPA-content group, corresponding to samples with between 0.3 and 1.70 ng/mg protein, proved to have a significantly high risk of relapse. We found a wide variability in tPA levels in gastric carcinoma and adjacent mucosa samples, with significantly decreased levels in tumors and a significantly positive relationship between tPA levels and ER status. There was a non-monotonic relationship between tPA levels and prognosis in patients with gastric cancer.