Clinical Value of Thymidine Kinase in Patients with Cervical Carcinoma

Abstract

Objective: Our purpose was to determine the clinical value of thymidine kinase (TK), which is an important pyrimidine pathway enzyme involved in salvage DNA synthesis, in patients with cervical carcinoma. Methods: We examined TK mRNA expression by reverse transcription polymerase chain reaction in 19 tissue specimens of invasive cervical carcinoma and 9 normal cervices and related it to thymidylate synthase (TS) and thymidine phosphorylase (TP) mRNA expressions. Serum TK level was determined by radioenzymatic assay in 79 patients with invasive cervical carcinoma, 7 patients with microinvasive carcinoma, 21 patients with carcinoma in situ and 32 normal women. Results: TK mRNA expression was upregulated in invasive cervical carcinoma compared with the normal cervix (p < 0.05) and significantly correlated with TS mRNA expression (p < 0.0001) but not with TP mRNA expression. The serum TK level was significantly higher in patients with invasive carcinoma than in normal women and patients with carcinoma in situ (p < 0.01 and p < 0.05). In patients with invasive cervical carcinoma, the serum TK level significantly correlated with TK mRNA expression (p < 0.05), but not with any conventional clinicopathologic factors. High serum TK levels significantly correlated with a poorer survival (p < 0.05), and multivariate analysis showed serum TK level to be an independent prognostic factor (p < 0.05). Conclusion: TK may play an important role in influencing the malignant behavior of cervical carcinoma, and measurement of the serum TK level may be useful in predicting survival in patients with cervical carcinoma.