Studies on the neutropenia of cancer chemotherapy

Cancer patients who are receiving chemotherapy are considered to be at an increased risk of infection when the peripheral neutrophil count falls below 2000 cells/mm3. To protect them from such risk, the treatment is discontinued. The size of the marginal neutrophil pool, the extent of marrow neutrophil reserves, the patient's ability to develop a tissue neutrophil and mononuclear cell response to a non-specific inflammatory stimulus, and the in vitro metabolic activity of neutrophils were measured in 25 patients with solid tumors betore and after a course of chemotherapy. Results indicate that infection only occurred with a depression of marrow neutrophil reserves and/or a depression in the tissue neutrophil and mononuclear cell response to non-specific inflammation. The functional capability of neutrophils, as measured by the in vitro metabolic responses to phagocytosis of latex particles, remained intact despite peripheral neutropenia. Chemotherapy may be safely continued, despite peripheral neutropenia, as long as the marrow reserves and tissue leukocyte inflammatory responses remain intact.