Effect of surgery on tumor-induced accelerated coagulation in a rat carcinoma

Accelerated coagulation detected by thromboelastography has been reported in early stages of tumor growth. The present investigation was conducted to determine the changes in tumor-induced accelerated coagulation following complete and partial resection of the tumor. Male Fisher rats were divided into four groups: (1) control, (2) tumor-bearing rats, (3) complete resection, (4) partial resection. In groups 2, 3, and 4 a 2-mm³ piece of squamous cell carcinoma (NCI 11095) was implanted subcutaneously in the left flank. Seven days later blood samples were obtained from the tumor and control groups and tested on a thromboelastograph to determine the effect of the tumor on the coagulation of the hosts. Six weeks following the initial tumor implantation a sham operation was performed on group 2, complete resection on group 3, and a partial resection on group 4. After a rest period of 3 weeks blood samples were obtained from the four groups of rats and tested on a thromboelastograph. The results indicate that there is a significant acceleration of coagulation in tumor-bearing animals. The effect of surgery on this tumor-induced phenomenon depends on the type of procedure performed. Complete resection returns the coagulation status toward normal whereas sham operation or a partial resection do not. In this tumor model, hypercoagulability of the blood, therefore, indicates the presence of residual tumor.