Expression of thymidine phosphorylase in human cervical cancer

Our aim was to evaluate whether the expression of thymidine phosphorylase (TP) by cervical cancer cells is correlated with the density of microvessels within the tumor, histopathologic features, and prognosis.

Sections of 55 cervical cancers (30 of stage IB, 5 stage IIA, and 20 stage IIB) were analyzed for the cellular expression of TP and the intratumoral density of microvessels by immunohistochemistry using monoclonal antibodies to TP and Factor VIII related antigen, respectively. The main outcome measures were the histopathologic features (histologic type, the maximum longitudinal diameter of the tumor, depth and degree of cervical stromal invasion, lymph-vascular space invasion, parametrial invasion, corpus invasion, vaginal invasion, and pelvic lymph node metastasis), whether or not the tumor cells were TP positive or TP negative, the microvessel count, and disease-free survival.

Twenty-nine tumors (52.7%) were classified as TP-positive. The microvessel count (mean +/- SD, 45.6 +/- 12.8) in TP-positive tumors was significantly higher than that (mean +/- SD, 24.3 +/- 9.6) TP-negative tumors (P < 0.0001, Mann-Whitney U test). The disease-free survival of the patients with TP-positive tumors was significantly less than those with TP-negative tumors (P = 0.044, log-rank test). Multivariate analysis revealed that pelvic lymph node metastasis was to be the only independent prognostic factor for disease-free survival (P = 0.041). Moreover, disease-free survival in patients with TP-negative was longer than that in those with TP-positive in pelvic lymph node-negative subgroup, but this did not reach significance (P = 0.247, log-rank test).

Although the expression of TP is not an independent prognostic factor in cervical cancer, it indicates a significantly decreased disease-free survival in patients with TP-positive tumors. These findings provide a potential for new therapeutic intervention mediated by nature that TP inherits in cervical cancer.