Human serum deoxythymidine-5'-triphosphatase activity as a parameter in the diagnosis and follow-up of large bowel carcinoma.

Serum deoxythymidine-5'-triphosphatase (dTTPase) levels were determined in 71 patients with large bowel cancers at different clinical stages: 10 patients in Duke's Stage A; 37, in Duke's Stage B; and 24, in Duke's Stage C. The dTTPase values of patients in Duke's Stage B and C are significantly elevated over normal healthy controls, and a correlation was observed between tumor stage and dTTPase activity. While dTTPase levels rise in patients with increasing tumor burdens, they decline in patients with undetectable tumor tissue after radical surgery. Six of 15 courses are documented, illustrating that, after successful operation, enzyme levels revert to normal. In all patients, carcinoembryonic antigen levels were determined along with dTTPase values, and both sets of data were correlated with each other indicating a correlation coefficient of zero. So, if both dTTPase and carcinoembryonic antigen are taken into account, the sensitivity of detection of colorectal carcinomas rises to 66% for all patients and to 92% for patients with a colorectal carcinoma of Duke's Stage C.