Tumor-associated hyperamylasemia.

Studies were made in eight patients with hyperamylasemia associated with cancer of the lung, pancreas or colon. Isoamylase analysis, conducted in seven of the eight patients revealed that the dominant isoamylase component was S-type in three and P-type in three; in one patient both isoamylases were elevated about equally. Examination of the serum or urine of the same seven patients for subcomponent isoamylase disclosed the presence in two of the seven of an unusual isoamylase designated "Y-type". This subcomponent isoamylase was also found in some samples of human milk, but not in normal persons or in patients with a variety of disorders other than cancer. The significance of hyperamylasemia occurring in association with cancers, the factors responsible for the variability in isoamylase pattern in those with hyperamylasemia, and the relationship, if any, of the "Y" isoamylase form to cellular growth and replication are all presently obscure and remain to be elucidated.