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.