Formalinized tumour cells in the leucocyte migration inhibition test

Immunization studies indicate that formalinized tumour cells retain at least part of their gross membrane structure and antigenicity; they are relatively easy to prepare and store well over a period of months. We have used formalinized tumour cells as antigen in the leucocyte migration inhibition test. Leucocyte migration inhibition occurred in leucocytes from thirty-eight out of sixty-nine malignant melanoma patients and from fifty-five out of eight-one breast cancer patients when in contact with formalinized tumour cells of a histologically similar type. Melanoma patients' and breast cancer patients' leucocytes were infrequently inhibited on contact with cells from histologically dissimilar human tumours and from xenogeneic mouse melanomas. Other advantages of formalinized cells over antigens prepared by homogenizing tumour tissue include a greater degree of inhibition and the ability to demonstrate a dose-response relationship between the ratio of leucocytes:tumour cells and the migration index.