title: A monoclonal gammopathy precedes multiple myeloma in most patients.
abstract: Preexisting plasma cell disorders, monoclonal gammopathy of undetermined significance, or smoldering myeloma are present in at least one-third of multiple myeloma patients. However, the proportion of patients with a preexisting plasma cell disorder has never been determined by laboratory testing on prediagnostic sera. We cross-referenced our autologous stem cell transplantation database with the Department of Defense Serum Repository. Serum protein electrophoresis, immunofixation electrophoresis, and serum free light-chain analysis were performed on all sera collected 2 or more years before diagnosis to detect a monoclonal gammopathy (M-Ig). In 30 of 90 patients, 110 prediagnostic samples were available from 2.2 to 15.3 years before diagnosis. An M-Ig was detected initially in 27 of 30 patients (90%, 95% confidence interval, 74%-97%); by serum protein electrophoresis and/or immunofixation electrophoresis in 21 patients (77.8%), and only by serum free light-chain analysis in 6 patients (22.2%). Four patients had only one positive sample within 4 years before diagnosis, with all preceding sera negative. All 4 patients with light-chain/nonsecretory myeloma evolved from a light-chain M-Ig. A preexisting M-Ig is present in most multiple myeloma patients before diagnosis. Some patients progress rapidly through a premalignant phase. Light-chain detected M-Ig is a new entity that requires further study.
authors.affiliation: Hematology-Oncology Service, Department of Medicine, Walter Reed Army Medical Center, Washington, DC 20307, USA. brendan.weiss@us.army.mil
authors.forename: Brendan M
authors.initials: BM
authors.lastname: Weiss
authors.forename: Jude
authors.initials: J
authors.lastname: Abadie
authors.forename: Pramvir
authors.initials: P
authors.lastname: Verma
authors.forename: Robin S
authors.initials: RS
authors.lastname: Howard
authors.forename: W Michael
authors.initials: WM
authors.lastname: Kuehl
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis / Q000097:blood; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D010265:Paraproteinemias / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D011230:Precancerous Conditions / Q000097:blood / Q000150:complications* / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D007136:Immunoglobulins