Expression of platelet-derived growth-factor B-chain mRNA and tumor angiogenesis in invasive transitional cell carcinoma of the upper urinary tract.

In several types of carcinoma, angiogenesis is associated with metastasis and might be a prognostic indicator. Platelet-derived growth factor (PDGF) is one of several growth factors known; it is involved in the regulation of cell migration and proliferation. There have been few reports, however, dealing with the expression of PDGF B-chain mRNA and angiogenesis in transitional cell carcinoma. We evaluated both the expression of PDGF B-chain mRNA and angiogenesis in transitional cell carcinoma of the upper urinary tract and examined their interrelation with metastasis, patient prognosis, and other established clinicopathologic parameters. For this purpose, formalin-fixed, paraffin-embedded tumor tissues from 91 patients with invasive tumors were analyzed with in situ hybridization for PDGF B-chain mRNA and immunohistochemical staining of Factor VIII-related antigen to assess angiogenesis. The expression of PDGF B-chain mRNA was positive in 59 (66%) of the 91 patients. Microvessel density was significantly increased in positive PDGF B-chain mRNA cases (P < .0001). There was no significance, however, in any relationship between the expression of PDGF B-chain mRNA or between the microvessel density and the clinicopathologic findings, metastasis, or prognosis. Assessment of the expression of PDGF B-chain mRNA and microvessel density seems to be of no real value in predicting either the risk of metastasis or the prognosis in transitional cell carcinoma of the upper urinary tract.