The need to establish whether the leukocyte adherence inhibition test is a reliable assay of tumor immunity in humans.

Lymphocytes from human cancer patients can react to tissue-type-specific antigens shared by many tumors of the same histological type and different for tumors of different types. Such reactions have been detected, for example, by using microcytotoxicity assays and leukocyte migration inhibition techniques. Work presented at this workshop indicates that the leukocyte adherence inhibition test is an excellent assay for detecting reactivity to antigens shared by neoplasms of the same histological type. However, very little is known of the nature of these antigens; for example, we do not know whether they are tumor specific or just normal tissue antigens. The usefulness of the leukocyte adherence inhibition test for patient monitoring and for diagnostic purposes also needs to be studied more.