Suppressor cells and survival of patients with advanced gastric cancer.

The association of suppressor cells with survival of patients with gastric cancer was investigated. Phytohemagglutinin (PHA)-induced lymphocyte response and the presence of nonspecific suppressor cells were assessed in patients with different stages of gastric cancer. The presence of suppressor cells was determined by their ability to inhibit the PHA response of normal peripheral blood mononuclear leukocytes. Depression of the PHA response was related to the stage of disease and was also associated with the presence of suppressor cells. Of 245 patients tested, 76 (31%) had suppressor cells. Adherent, nonspecific esterase-positive cells (presumably, monocytes) accounted for the suppression in most cancer patients. The occurrence of suppressor cells and the tumor load were related because the incidence of detectable suppressor cells decreased after surgery in patients with resectable tumor but increased in patients undergoing palliative surgery. In patients with advanced disease who had a generally poor prognosis, the occurrence of suppressor cells was associated with a significantly increased survival. Hence the common view that a depressed lymphocyte response correlates with a poor clinical outcome may not be valid in all types of cancer.