Some reflections on myeloma

Half-Body Irradiation in the Treatment of Multiple Myeloma: A Report of Nine Cases

We report the results of treatment of 9 patients with advanced multiple myeloma (MM) using half-body irradiation. Six nonresponders to chemotherapy received it as consolidation therapy after the plateau phase of MM had been observed, and 4 patients received it as salvage therapy of refractory or relapsing MM. One of the patients received it twice, first as consolidation and later during the course of her disease also as salvage therapy. Objective response was obtained in 1 of 6 patients who received half-body irradiation as consolidation therapy and in 3 of 4 patients who received it as salvage therapy. Responders to half-body irradiation generally achieved a longer relapse-free interval. Treatment with half-body irradiation was especially effective in combination with human leukocyte interferon as salvage therapy in 2 of the patients with refractory MM, leading to a relapse-free interval of more than 27 months in one of them. Symptomatic relief was observed in 5 of 6 patients. All had transient post-irradiation pancytopenia, with pneumonitis, nausea and vomiting observed in those who had the upper half of the body irradiated first. It is thus our opinion that half-body irradiation should not be used as consolidation therapy in nonresponders to chemotherapy, because it causes undue toxicity to heavily pretreated patients. Its role in the treatment of refractory or relapsing MM in combination with human leukocyte interferon should be fully evaluated.

Myeloma

Myeloma is a malignancy of plasma cells that are terminally differentiated B-lymphocytes. The clinical spectrum varies from the incidental discovery of a pathologically raised monoclonal immunoglobulin on routine electrophoresis in asymptomatic patients to widespread skeletal involvement with incapacitating bone pain. Symptoms may result from a solitary tumor mass, described as an extramedullary plasmacytoma, in virtually any part of the body. Metabolic abnormalities commonly include hypercalcemia, elevated plasma urate levels, or the development of amyloidosis, all of which may disturb renal function. High paraprotein levels cause hyperviscosity, resulting in generalized debility and varying degrees of disturbed mental function. The natural history is determined by the mass of the tumor coupled with its unique biologic features. Median survival of unselected patients, without effective treatment but once symptoms are evident, is approximately 7 months; this period can be significantly prolonged with appropriate therapy. As a first step, urgent medical management is often necessary, centering on rehydration, correction of hyperviscosity, and reversal of metabolic defects, each of which may improve renal function. Over the longer term, specific antitumor drugs have extended median survival to approximately 30 months, and most regimens include a combination of melphalan and prednisone, with or without other cytotoxic drugs. Alternative forms of treatment include sequential hemibody irradiation, recombinant alpha interferon, and in suitably selected patients, high-dose chemoradiotherapy followed by bone marrow transplantation. The latter approaches offer promising management options and are currently the subject of evaluation in controlled clinical trials.

Diagnostic value of the concentration of M-component in initial classification of monoclonal gammopathy

The diagnostic value of the concentration of a serum M-component in initial classification of monoclonal gammopathy into malignant monoclonal gammopathy (MMG) and monoclonal gammopathy of undetermined significance (MGUS) was evaluated in 315 consecutive individuals with IgG, IgA or IgM type M-components. The final diagnosis was MMG in 84 and MGUS in 231 patients. Serum concentration was significantly highest in MMG, but for all 3 kinds of M-components, overlapping serum concentrations between MMG and MGUS were found. Highest efficiency was reached with a serum concentration of 30.2 g/l for IgG, 26.6 g/l for IgA and 22.7 g/l for IgM. Using these values, an initial correct classification was achieved in 0.90 of IgG M-components, in 0.91 of IgA M-components and in 0.79 of IgM M-components. Normal levels of uninvolved immunoglobulins were found to point strongly to MGUS.