Cellular immunity to breast carcinoma and malignant melanoma.

We have examined the effect of extracts of benign and malignant tumours on the migration of leucocytes from the peripheral blood of 55 melanoma patients, 73 breast carcinoma patients and 162 control donors in the leucocyte migration test. The leucocytes from a majority of tumour bearing patients were inhibited on contact with extracts of histogenetically similar tumours but only occasionally by extracts of dissimilar tumours and preparations from non-neoplastic breast tissue. Control donor's leucocytes were rarely inhibited by any of the tissue extracts. In both patients with malignant melanoma and those with breast carcinoma there was a striking decline in the frequency of tumour extract mediated leucocyte migration inhibition in patients with metastases.