Response of human monocyte phagocytosis to FAM (fluorouracil, adriamycin, mitomycin)

The immunosuppressive effect of chemotherapy associated with surgery is poorly understood. The effect of combination chemotherapy--fluorouracil, adriamycin and mitomycin (FAM)--on monocyte phagocytosis was tested in patients operated on for gastric cancer. The adherence, engulfment and total phagocytic process were studied with a fluorescence-quenching technique 1 hour, 24 hours and 1 week after 19 FAM treatments in nine patients. The engulfment of yeast cells and the total phagocytosis were significantly impaired 1 hour post-treatment (p less than 0.05 and less than 0.01, respectively). These functions had normalized after 24 hours, but after 1 week the engulfment step was significantly depressed (p less than 0.05). Significantly increased adherence of yeast cells (p less than 0.05) was found at the same time. The initial, transient depression of monocyte phagocytosis probably was related to inactivation of cell-surface receptors. The late (1 week) depression probably was due to bone-marrow toxicity. This functional impairment of the blood monocytes was not reflected as clinical liability to infections.