The Ann Arbor staging classification has proven less useful in non-Hodgkin's lymphoma, because this malignancy is inherently a multifocal disorder. Since 1985, 57 adult patients with advanced B-lymphocytic malignancies that progressed despite standard therapy entered into one of three different therapy trials using radiolabeled Lym-1 antibody. Tumor regression in 31 (54%) of these patients fulfilled conventional requirements for an oncological response to the therapy. To define the role of radioimmunotherapy in B-lymphocytic malignancies better and to find opportunities for improving its therapeutic efficacy, the records of these patients were reviewed to assess the significance of various parameters as prognostic indicators. Twenty-one pretherapy characteristics were evaluated, including age at diagnosis, age at study entry, sex, Karnofsky performance status, prior chemotherapy and radiation therapy, interval since diagnosis, histology, constitutional B symptoms, extranodal malignancy (excluding marrow), bone marrow malignancy, tumor bulk, and circulating malignant cells; blood tests included lymphocyte, granulocyte, platelet, hematocrit, serum lactate dehydrogenase (LDH), interleukin 2 receptor, and human antimouse antibody levels. In the multivariate analysis, LDH and Karnofsky performance status were the parameters that best predicted survival, complete and partial remission, and time to progression; interleukin 2 receptor and LDH best predicted complete remission. These prognostic factors for radioimmunotherapy outcome are consistent with the pretherapy characteristics observed to be significant for chemotherapy.
Presented at the “Fifth Conference on Radioimmunodetection and Radioimmunotherapy of Cancer,” October 6–8, 1994, Princeton, NJ. Supported by NCI Grant PHS CA 47829 and United States Department of Energy Grant DE-FG03-84ER60233.