Alpha-globulins in the surveillance of colorectal cancer.

The alpha1 and alpha2-globulins have been studied at various stages in the evolution of colo-rectal cancer. The alph2 was elevated in some primary tumours and rose in metastatic cancer especially when it involved the liver. Some apparently tumour free patients had an unexplained elevation of alph2-globulins. The macroglobulins were not a major constituent of the raised alpha2-globulins. Haptoglobulin levels were found to be a useful indicator of tumour activity, when their level was raised in metastatic cancer it was usually with an antecedent or coincidental rise of plasma CEA. Primary tumours may cause a high haptoglobin response without an elevation of CEA.