Prognosis in monoclonal proteinaemia

Abstract

Monoclonal proteinaemia (M-proteinemia) is associated with multiple myeloma (MM) or other hematological malignancies. In the absence of these diseases the term MGUS (Monoclonal Gammopathy of Undetermined Significance) is used. During 1991-1993 1464 patients with newly diagnosed M-proteinemia in the mid-western of The Netherlands (1.6 million inhabitants) were registered in a database and followed annually. Information on characte_ristics, laboratory and bone marrow test results, skeletal-X-rays as well as M-protein related diagnosis were obtained. At diagnosis potential discriminatory serum markers like interleukin-6 and syndecan-1 proved to be of no informative value. The reported correlation between solid tumors and M-proteinemia was rather based on a diagnostic selection bias than on a causal role. Long-term follow-up (median 9.0 years for those alive) showed that survival of MGUS patients is reduced compared to an age-matched cohort of the Dutch population. Age, gender and serum albumen were important factors for survival; the annual 0.4% risk for malignant transformation was influenced by M-protein level and IgA-isotype. In MM early response to melphalan-prednisone chemotherapy as measured by the rate of serum M-protein decrement was of prognostic value. Interferon maintenance therapy in MM-patients prolonged progression free survival, but not overall survival without affecting quality of life.