title: Incidence, clinical course, and prognosis of secondary monoclonal gammopathy of undetermined significance in patients with multiple myeloma.
abstract: During the course of multiple myeloma (MM), new monoclonal proteins of an isotype distinct from the original clone, referred to as secondary monoclonal gammopathy of undetermined significance (MGUS), have been described. We report on the frequency, characteristics, and outcome of secondary MGUS. Of the 1942 patients with MM, 128 (6.6%) developed a secondary MGUS, at a median of 12 months from the diagnosis of MM. The median duration of secondary MGUS was 5.9 months. Secondary MGUS was more common in patients after stem cell transplantation than in those who had not undergone such treatment (22.7% vs 1.6%, P < .001). Overall survival was significantly superior in MM patients who developed secondary MGUS compared with the rest of the cohort (73 vs 38 months, respectively; P < .001). The time of onset and the duration of secondary MGUS, as well as failure to resolve spontaneously, had an effect on overall survival and require further study.
authors.affiliation: Department of Medicine, Mayo Medical School, Rochester, MN, USA.
authors.forename: Rishi K
authors.initials: RK
authors.lastname: Wadhera
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kyle
authors.forename: Dirk R
authors.initials: DR
authors.lastname: Larson
authors.forename: Angela
authors.initials: A
authors.lastname: Dispenzieri
authors.forename: Shaji
authors.initials: S
authors.lastname: Kumar
authors.forename: Hillard M
authors.initials: HM
authors.lastname: Lazarus
authors.forename: S Vincent
authors.initials: SV
authors.lastname: Rajkumar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D009101:Multiple Myeloma / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy; D011379:Prognosis; D016019:Survival Analysis