title: Malignant transformation of monoclonal gammopathy of undetermined significance: cumulative incidence and prognostic factors.
abstract: The cumulative incidence of malignant transformation was studied in 88 patients with monoclonal gammopathy of undetermined significance (MGUS) that had a complete prospective follow-up. At a median follow-up of 6.75 years, 10 patients developed multiple myeloma (MM) (11.4%) and 2 developed immunocytoma (2.3%). The cumulative incidence of malignant transformation was 9.1, 21.3, 38 and 48.3% at 5, 10, 15 and 20 years, respectively. In univariate analysis on 102 MGUS patients, M-component level, bone marrow plasma cell percentage and kappa light chain correlated significantly with the development of a malignancy (p=0.0289, 0.0265 and 0.0013, respectively). In multivariate analysis, light chain type of M-component and plasma cell percentage had independent prognostic significance. A high-risk (M-component level > 10 g/l and/or plasma cell percentage > 2%) and a low-risk group ( M-component level < 10 g/l and/or plasma cell percentage < 2%) of MGUS patients was identified, which differed significantly in the cumulative incidence of developing a malignancy (p<0.001 for M-component level and p=0.007 for plasma cell percentage). These results imply that high-risk patients should receive a more frequent follow-up, in comparison to low-risk patients.
authors.affiliation: Department of Haematology, University Medical Center Utrecht, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Van De Donk
authors.forename: O
authors.initials: O
authors.lastname: De Weerdt
authors.forename: M
authors.initials: M
authors.lastname: Eurelings
authors.forename: A
authors.initials: A
authors.lastname: Bloem
authors.forename: H
authors.initials: H
authors.lastname: Lokhorst
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001854:Bone Marrow Cells / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D015994:Incidence; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000378:metabolism / Q000473:pathology*; D010266:Paraproteins / Q000032:analysis; D010950:Plasma Cells / Q000473:pathology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D007145:Immunoglobulin kappa-Chains; D019394:Ki-67 Antigen; D010266:Paraproteins