Unusual isomaylase in cancer-associated hyperamylasemia.

Hyperamylasemia and hyperamylasuria were found in two patients with carcinoma of the pancreas and in two other patients with carcinoma of the lung. Detailed isoamylase analyses were conducted on the serum amylase of three and the urine amylase of all four of these patients, using a modified chromatographic procedure. The studies demonstrated the existence, in one of the lung cancer patients and in one of the patients with pancreatic cancer, of an unusual component of amylase given the designation "Y." This component had also been noted in some human milk samples. In one of the lung cancer patients, an isoamylase was found in the serum and urine after radiation treatment that was close to but not identical to the Y isoamylase in chromatographic position. Although a relationship of isoamylase component Y to generating tissue is suggested by these findings, such a relationship of isoamylase component Y to generating tissue is suggested by these findings, such a relationship remains to be proven.