Disappearance curves for tumor markers after resection of intrathoracic malignancies.

Determination of the standard elimination kinetics of tumor markers will be helpful in the diagnosis of malignancies. We analyzed the disappearance curves for serum tumor marker levels after resection of intrathoracic malignancies. Serum levels of CEA, SLX, AFP, CA 19-9, SCC, TPA and CYFRA were measured several times after surgery in a total of 40 patients. To obtain precise biological half-lives, we applied non-linear least square analysis, taking into consideration the possibility of residual tumor cells. Disappearance curves were monophasic for CEA, SCC, TPA, CYFRA and SLX and biphasic for CA 19-9 and AFP. Temporary elevation of serum levels after surgery was observed for SCC, TPA and CYFRA. The average half-lives of CEA, SLX, SCC, TPA and CYFRA were 1.5 days, 2.7 days, 2.2 hours, 2.5 hours and 1.5 hours, respectively. The average half-life of CA 19-9 was 0.5 days in the first compartment and 4.3 days in the second compartment, while that of AFP was 1.0 days and 6.3 days, respectively. These values will be helpful in the interpretation of serum tumor marker levels after surgery.