Ki67 and 4F2 antigen expression as well as dna synthesis predict survival at relapse/tumour progression in low‐grade B‐cell lymphoma

Abstract

Previous work has shown that parameters of cell activation studied on lymphoma biopsies can be used to discriminate between low‐grade and high‐grade non‐Hodgkin's lymphomas and to predict prognosis in the low‐grade malignancy group alone. We have now examined expression of several activation antigens and indicators of DNA synthesis in 29 patients with low‐grade malignant B‐cell lymphomas at the time of primary diagnosis and later at relapse and/or tumour progression. At both times, the level of 4F2 antigen expression examined by flow cytometry on cells in suspension as well as the number of Ki67 antigen‐positive cells examined by immunohistochemistry were predictive of patient survival. DNA synthesis estimated by (³H‐TdR) thymidine incorporation was of prognostic value at the second biopsy only. These parameters were more sensitive than histological demonstration of morphological transformation in secondary high‐grade lymphomas in identifying high‐risk patients at repeated biopsy. We propose that Ki67 or 4F2 expression or a marker of DNA synthesis (such as ³H‐TdR incorporation or labelling index) should be evaluated when repeated biopsies are performed, in order to select patients for whom aggressive chemotherapy may be considered.