A study of immunoreactive calcitonin (CT), adrenocorticotropic hormone (ACTH) and carcinoembryonic antigen (CEA) in lung cancer and other malignancies

Abstract

Levels of immunoreactive ACTH and calcitonin (CT), as well as CEA, were determined serially in 144 patients with lung cancer and in 62 patients with metastatic carcinoma to the lungs. Patients with neoplasms not involving the lungs, with nonmalignant blood dyscrasias, and with chronic obstructive pulmonary disease were studied, as were normal control subjects. In 55–91% of lung cancer patients, elevated values of CT were detected; the frequency of elevation varied with cell type and stage. The highest values (mean 1346 ± 2534 pg/ml) were found in patients with extensive small cell lung carcinoma (SCLC) and were significantly greater than the values for patients with SCLC confined to one hemithorax (196 ± 287.7 pg/ml, P < 0.005). ACTH levels were elevated less frequently (24–46%) and were highest (192 ± 200.9 pg/ml) in patients with extensive small cell carcinoma, although Cushing's syndrome was observed only once. Agreement between all three tumor markers was seen in 25–50% of lung cancer patients; the percentage depended on cell type. Calcitonin levels paralleled changes in the clinical status and tumor burden in 89% of SCLC patients, while ACTH levels reflected the clinical course in 67%. In six patients with small cell carcinoma in remission, rising levels of CT, ACTH, and CEA preceded clinical evidence of relapse, in one patient, by as long as five months. Among 129 patients with conditions other than primary lung cancer, CT levels were highest (232 ± 328 pg/ml) in those with cancer metastatic to the lungs and/or pleura; there was no association between CT levels and the presence of bone metastases.