Expression of thymidine phosphorylase in uterine sarcoma and uterine leiomyoma: association with microvessel density and Doppler blood flow analysis.

The aim of this study was to determine whether the expression of thymidine phosphorylase (TP) by uterine sarcoma and leiomyoma cells is associated with the density of microvessels within the tumor, and with Doppler ultrasound-derived peak systolic velocity (PSV) of blood flow. Sections of tissue from four uterine sarcomas and 41 uterine leiomyomas which had been used in a previous study to determine intratumoral peak systolic velocity were analyzed for the cellular expression of TP and the intratumoral density of microvessels by immunohistochemistry, using monoclonal antibody to TP and factor VIII-related antigen, respectively. The main outcome measures were whether or not the tumor cells were TP-positive or TP-negative, and the microvessel count within each tumor type. Uterine sarcomata were classified as TP-positive and uterine leiomyomata as TP-negative. The microvessel count in uterine sarcomas was significantly higher than that in uterine leiomyomas (p = 0.002, Mann-Whitney U test). We concluded that the expression of TP by uterine sarcoma cells is associated with an increase in microvessel density and with a higher peak systolic velocity.