Serum TK1 protein levels can predict survival of prostate cancer patients

A recent study has shown that serum thymidine kinase 1 (sTK1) protein levels can predict the survival of patients with metastatic prostate cancer. The results also suggest that sTK1 is useful for predicting which patients that may be benefitted by docetaxel chemotherapy. The study examined 261 patients divided into three retrospective cohorts with a primary focus on overall survival and an up to 20-year follow-up period. sTK1 was measured using the TK 210 ELISA from AroCell AB.

The results of the study show that sTK1 levels were elevated in the blood of patients with metastatic prostate cancer, including both newly diagnosed patients and patients with castration-resistant disease. Importantly, a strong association between elevated sTK1 levels and patient survival was observed. Thus, patients with elevated sTK1 had an approximately 3-fold higher risk for an adverse outcome compared to patients with lower levels of sTK1. The association between sTK1 and poor survival remained significant in multivariate analyses including adjustment for Gleason score, PSA level, and clinical T-stage. sTK1 therefore contributes important clinical information not obtained using other markers.

The association between elevated sTK1 levels and poor survival was particularly strong in prostate cancer patients treated with antihormonal drugs. In contrast, a more favorable outcome was observed when patients with high sTK1 levels were treated with docetaxel chemotherapy. Docetaxel is known to target proliferating cells and the results suggest that the proliferation-associated marker sTK1 can be used to identify tumors that are sensitive to this drug.
 
The results of the study has been submitted and accepted as an abstract for a presentation at the PAMM/EORTC conference in February. The study was performed in collaboration with Tampere University, the Medical University of Vienna, and the Semmelweis University in Budapest.
 
“We are very pleased with these results, which confirm previous findings showing that AroCell's TK 210 test can be used to predict the prognosis of patients with metastatic prostate cancer. The results also raise the possibility of using the TK 210 test for the selection of patients for different treatment options,” says Anders Hultman, CEO of AroCell.