[Early judgement on the results in radiation therapy of colorectal cancer: determination of carcinoembryonic antigen (CEA) in blood serum at daily intervals from the beginning of irradiation (author's transl)]. / Frühzeitige Erfolgsbeurteilung der Strahlentherapie von rektosigmoidalen Karzinomen. Die Bestimmung des Karzinoembryonalen Antigens (CEA) im Serum in Tagesabständen zu Beginn der Bestrahlung.

Carcinoembryonic antigen (CEA) and lactatedehydrogenase (LDH) as tumor cell markers have been determined in the blood serum of 10 patients with colorectal cancer, who underwent preoperative irradiation with 200 to 250 rad daily (total focal dose 2000 to 2500 rad). Daily analysis was made during the irradiation, and, moreover, a determination 2 weeks after the resection of the tumor. Simultaneously CEA and LDH were determined in 10 controls. Serum CEA and LDH levels were found significantly increased in tumor patients as compared to controls. The course was characterized by a peak of LDH on days 4 and 7 from the onset of radiation treatment, while serum CEA did not show a peak in the total of the tumor patients; but in 3 individual patients a peak was detected. In 5 patients, with low CEA values from the beginning, no significant modifications of CEA did appear. Thus, some of the patients undergoing irradiation revealed CEA kinetics conform to theoretical considerations, suggesting a response to irradiation of the colorectal carcinoma. The prognostic value of the early CEA kinetics during radiation treatment should be examined in patients being irradiated for inoperable local recurrence.