Effect of thrombin tube on PSA determination, a clue for false negative in screening for prostate cancer.

Prostate cancer is an important male carcinoma. Laboratory screening for tumor marker is the routine preventive strategy for control of this cancer. For screening, prostate specific antigen (PSA) has been proposed as a marker in the serum. In this article, the author assesses the effect of new blood collection tube, thrombin tube, on the analysis of the PSA by bioinformatics technique. Using GoFigure server, the molecular functions of thrombin, PSA and thrombin-PSA were predicted. A significant change of molecular function due to the interaction between thrombin and PSA can be found. Increased of coagulation due to the synergistic clot activation can be expected. If this occurs, the false negative can be expected and it can bring the underdiagnosis of early prostate cancer. Therefore, the recommendation for usage of thrombin tube for PSA test should be modified from general usage. Shortening of the period between blood collection and sample analysis than general case must be done.