Immunity in colonic tumor patients after operation: determination by leukocyte-migration inhibition.

Tumor immunity in 31 colonic tumor patients was studied by determining in vitro leukocyte-migration inhibition. In tissue culture 30 per cent inhibition of patient leukocyte migration by tumor antigen could be demonstrated in half of the patients, suggesting that they were immune. This immunity was not related to the clinical or pathologic stage of the disease and varied in different patients. It was transient in some and persistent in others. In addition, a positive response at a fixed time after operation was not found.