The effect of immunosuppressive chemotherapy on immune function in patients with malignant disease.

This paper reviews studies previously conducted on the effect of anticancer drugs on immune function in man. It provides new data reporting on the effect of short intensive courses of cytotoxic drug therapy on B-lymphocyte and T-lymphocyte number in cancer patients. Both types of lymphocyte were found in this investigation to be equally sensitive to cytotoxic drugs. The degree of absolute cell number reduction and rate of recovery were similar for T-lymphocytes and B-lymphocytes. Other workers have demonstrated, however, that with prolonged administration of cytotoxic drugs B-lymphocyte number and function are more adversely affected than are T-lymphocyte number and function. Immune function which had been suppressed by continuous programs of chemotherapy for periods of up to 2-3 years will, in certain groups of patients, recover to normal or almost normal levels of function. Short courses of combination drug chemotherapy may be followed by "rebound-overshoot" recovery of immune function. This has been associated with a more favorable clinical course than in situations where it does not occur. Chemotherapy and chemoimmunotherapy programs in clinical oncology ought ideally to be initially evaluated for the effect that they have on immune function. This will permit the development of drug dose and time schedules which allow for recovery of immune function and may possibly lead to augmented antitumor responses.