1. ¹Department of Pathology, Democritus University of Thrace, Alexandroupolis, Greece
2. ²Department of Urology, Democritus University of Thrace, Alexandroupolis, Greece
3. ³Nuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, Oxford OX3 7LJ, UK
4. ⁴Molecular Oncology Laboratories, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS, UK
5. ⁵Department of Radiotherapy/Oncology, Democritus University of Thrace, Alexandroupolis, Greece

Correspondence: E Sivridis, Department of Pathology, Democritus University of Thrace, P.O. Box 128, Alexandroupolis 68100, Greece. E-mail: esivrid@med.duth.gr

Received 24 September 2001; Revised 14 February 2002; Accepted 27 February 2002.

Abstract

Thymidine phosphorylase is an angiogenic factor primarily expressed by cancer cells, stromal cells and tumour-associated macrophages in many human malignancies. These different types of thymidine phosphorylase-expressing cells, however, may have a distinct place in the angiogenic process, and this question was addressed in the present study. A series of 20 normal/hyperplastic prostate glands and 60 prostate carcinomas was investigated by immunohistochemistry, using specific antibodies for thymidine phosphorylase (P-GF.44C), tumour-associated macrophages (CD68), endothelium (CD31) and prostate specific antigen (ER-PR8). Thymidine phosphorylase expression by normal and hyperplastic epithelial or stromal cells occurred almost exclusively in the context of an intense lymphocytic infiltrate. High thymidine phosphorylase cancer cells and thymidine phosphorylase stromal cells expression was associated with high angiogenesis in prostate carcinomas, and this significant association was extended to include both tumour-associated macrophages and tumour-infiltrating lymphocytes. Thymidine phosphorylase expression and tumour-infiltrating lymphocytes were related inversely with prostate specific antigen reactivity. In conclusion, thymidine phosphorylase is a major angiogenic factor in prostate carcinomas and its up-regulation is likely to occur in the context of a host immune response.