Augmentation of E-rosette formation by lymphocytes of cancer patients stimulated in vitro with tumor extracts.

The ability of tumour extracts to augment E-rosette formation by cancer patients' lymphocytes was demonstrated for colorectal carcinoma, breast carcinoma and melanoma. Positive augmentation reactions were obtained with 14 to 20 patients tested with extracts related to their own tumour types. Some lack of specificity was suggested by 5 positive reactions in the same patients tested with unrelated extracts. No false positives were found in normal subjects. The technique is simple, rapid and appears to depend on tumour-associated antigens in the extracts. Simultaneous leucocyte adherence inhibition tests on split samples of blood had a high degree of sensitivity and specificity, confirming the potential reactivity of the leucocytes and extracts used.