Characterization of cell-mediated immunity in long-term survivors of gastric or colorectal cancer.

Cell-mediated immunity was assessed in 12 patients who were long-term survivors of gastric and colorectal adenocarcinomas. A slight decrease in the T-lymphocyte count was accompanied by preserved proliferative reactivity to mitogens (phytohemagglutinin) or alloantigens in 75 percent of the patients. The influence of autologous patient serum on in vitro lymphoproliferative test results was not significant. Selected sera from both study groups showed values of immune complexes that were within the normal range. The colorectal cancer group had antibody-dependent cellular cytotoxicity within the ranges already established for the normal control subjects. Cellular immune mechanisms seem to have been well preserved in long-term survivors of gastric or colorectal carcinoma.