Prostate Cancer (PCa) is the most commonly diagnosed cancer and the second leading cause of cancer related deaths in men. Although measurement of prostate-specific antigen (PSA) has been a cornerstone in follow-up of PCa patients, clinical progression has been reported without a rising PSA in both early-stage and metastatic cases. To date, there are few serological biomarkers that indicate the rate of cellular proliferation which could provide valuable information for monitoring patients and making prognosis. Thymidine kinase 1 (TK1) is a key enzyme in DNA precursor synthesis. The development of immunoassays for TK1 based on antibodies directed against the TK1 "210" epitope enables all serum TK1 forms to be assayed. Aim of the study is to prospectively analyze serum TK1 levels in a cohort of early-stage PCa patients undergoing radical prostatectomy (RP) and, in a second cohort of advanced metastatic PCa, to investigate its possible role as a response biomarker after treatment with androgen deprivation therapy (ADT).
In this prospective study, 150 patients diagnosed with PCa will be enrolled. Based on PCa stage and treatment received, our population will enclose 2 settings of PCa patients: "RP group" and "ADT group". TK1 and total PSA samples will be collected at different follow-up intervals. All patients will be followed in order to detect disease progression.
The development of TK1 immunoassays has made the assay of TK1 more widely available and increased its applicability to solid tumor diseases, as PCa. To date, very few studies have evaluated the utility of serum TK1 in monitoring responses to cancer therapies, and none have analyzed the level of TK1 and its modifications after treatments in patients with early-stage and metastatic PCa.
