Reactivity of gastric cancer patients in leucocyte migration inhibition tests to 3M KCl extracts from gastric tumor.

Leucocytes from patients with gastric cancer and other malignant and non-malignant diseases of the gastrointestinal tract as well as from healthy controls were tested for leucocyte migration inhibition test (LMI) using five different, allogeneic 3M KCl soluble extracts from gastric cancer tissues. The normal range of migration index (MI) was considered to be between 0.77 and 1.18 by calculating the mean MI +/- 2SD of ten healthy controls with cancer extracts. MIs out of this range were considered to be pathologic. In LMI test with a single tumor extract, pathologic MI was found in 48% of 79 gastric cancer patients, such being significantly higher than in those (4-21%) of three other groups of patients. In the panel mode of LMI, i.e., testing each blood sample with five different tumor extracts, 79% (62/79) of patients with gastric cancer were reactive, while 25% (5/20) of colorectal cancer patients showed "positive" reaction and no "positive" reactivity was observed in two other groups of patients. Thus, the "positive" reactivity in patients with gastric cancer was observed significantly higher than those in the other 3 groups of patients. Gastric cancer extracts had a wide range of cross-reactivity when compared with colorectal tumor extracts which showed a relatively restricted cross-reactivity. Thus, the LMI tests, particularly when tested by a panel mode, seems to express cell-mediated immunity against tumor associated antigens of gastric cancer.