Effect of human tumor antigens on the active E-rosette-forming test (ARFT): a new diagnostic method for cancer

The "active" T-cell test was adapted into an in vitro assay for response to human tumor antigens, especially gastric, lung, liver, esophageal, and colonic tumors. Peripheral blood lymphocytes were isolated from 229 cancer patients, 60 non-cancer patients, and 70 normal adults. Tumor antigen, incubated with lymphocytes from patients with the corresponding cancer, produced a significant increase in the ability of the lymphocytes to function as active rosette-forming cells (ARFC) when compared with lymphocytes cultured without antigen (P less than 0.001). This potentiating effect on ARFC remained unimpaired even after tumor antigen refrigeration. Tumor antigen incubated with lymphocytes from normal donors produced no increase in ARFC ability. This assay appears to be specific for the antigen corresponding to the cancer of the given patient; for example, gastric tumor antigen increased the ARFC of gastric cancer patients, but produced no increase in ARFC of breast cancer patients. No interference by the HLA complex was found in this assay. This technique provides a novel in vitro method for investigating cell-mediated immunity and also a new, specific method for cancer diagnosis.