An examination of the immunology of cancer patients.

We have examined 111 cancer patients and 111 control individuals for general immunocompetence (haematological values, "recall" antigen skin tests, PHA and PPD induced lymphocyte transformation, serum Ig levels and lymphocyte subpopulations), for evidence of sensitisation to tumour-associated antigens (leucocyte migration test, serum inhibition of autologous leucocyte migration, lymphocytotoxicity, membrane immunofluorescence and immune adherence) and for evidence of continuing immune reactions (alterations of complement components and anticomplementary activity). Major differences between the cancer patients and controls were demonstrated by several tests of sensitisation and these also detected differences between patients with and without metastases. The only differences detected between cancer patients and controls by the tests of general immunocompetence were in serum IgG and IgA (higher in the cancer patients) and lymphocyte subpopulations ("active" T, autorosetting lymphocytes and lymphocytes forming "super-rosettes" increased in cancer patients). In a comparison of cancer patients with and without metastases, patients with metastases were less often reactive to the Candida DHS and streptokinase-streptodornase antigens and had raised circulating Fc positive cells. Abnormalities of the individual components of complement occurred in about half the cancer patients, but were equally common in those with and without metastases. Serum anti-complementary activity was very rarely detected. The tests of specific sensitisation correlated reasonably well but correlations of tests of general immunocompetence were infrequent.