AN ASSAY FOR MONITORING RESPONSE TO THERAPY IN CANCER-PATIENTS

Immunosuppression is characteristic of patients with advanced malignan t neoplasms. However, none of the simple assays for immunocompetence h ave been found to provide results which correlate with the patients' r esponses to therapy. The data reported here indicate that this may be because there are artifacts in data from earlier studies which have ob scured such a correlation. A simple assay which removes previously unr ecognized sources of error is shown to generate data which correlate w ell with patient responses. In this assay, lymphocytes collected from patients with malignant solid tumors were stimulated with mitogen in t heir autologous plasma. The amount of radioactive thymidine incorporat ed during replicative deoxyribonucleic acid (DNA) synthesis was correc ted to remove sources of error ignored in the previous studies. A sign ificant improvement in mitogen-stimulated synthesis was observed withi n two months for patients entering remission. For patients not respond ing to therapy, there was a progressive deterioration in mitogen-respo nsiveness.