ProACTH: use for early detection of lung cancer.

ProACTH was identified by radioimmunoassay and column chromatography in extracts of 38 lung carcinomas. One hundred patients were evaluated because of abnormalities on chest roentgenograms; 53 (72 per cent) of 74 with lung cancers had increased plasma ACTH immunoreactivity; all 26 with benign abnormalities had normal ACTH. Of 101 patients with obstructive lung disease, five of 20 with elevated plasma ACTH levels and two of 81 with normal plasma ACTH levels had lung cancer within two years. In three of 31 patients with granulomatous lung disease plasma ACTH levels were elevated during acute exacerbation of the disease, but they returned to normal after recovery. We conclude that plasma ACTH immunoreactivity is frequently increased early in the course of lung carcinoma.