Monoclonal gammopathy in Iceland: a population-based registry and follow-up

• Published in: British Journal of Haematology
• Main Authors: Ogmundsdottir, Helga M, Haraldsdottir, Vilhelmina, Johannesson, Gudmundur M, Olafsdottir, Gudridur, Bjarnadottir, Kristin, Sigvaldason, Helgi, Tulinius, Hrafn
• Other Authors: Molecular and Cell Biology Research Laboratory, Icelandic Cancer Society, Reykjavík, Iceland. [e-mail]
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Scientific Publications 2008
• Subjects: Adult; Age Distribution; Aged; 80 and over; Female; Follow-Up Studies; Humans; Iceland; Incidence; Male; Middle Aged; Monoclonal Gammopathies; Benign; Multiple Myeloma; Registries; Risk; Sex Distribution; Waldenstrom Macroglobulinemia
• Online Access: http://hdl.handle.net/2336/32582; https://doi.org/10.1046/j.1365-2141.2002.03589.x

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field The term monoclonal gammopathy (MG) signifies the benign or malignant clonal growth of B lymphocytes. In the present study, monoclonal gammopathy of unknown significance (MGUS) was defined as those patients with no identified haematological malignancy. A database was constructed of all 713 MG patients in Iceland between 1976 and 1997 and compared with the Icelandic Cancer Registry. The age-standardized incidence per 100 000 of MG was 10.3 for males and 8.6 for females, calculated for the whole period, rising steadily from 5.8 (men) and 4.9 (women) during the 5-year period 1976-80 to 14.7 (men) and 12.5 (women) during the last 5 year period. Age-standardized incidence rates were very low for subjects under 50 years of age, then increased with age from 11 and 17 per 100 000 at 50-54, to 169 and 119 per 100 000 at age 80-84, for men and women respectively. No association was detected between MG and non-haematological malignancies, neither retrospectively nor prospectively. Haematological malignancy was diagnosed in 209 (29.3%) cases before the recorded finding of MG or within the same calendar year, leaving 504 (70.7%) patients diagnosed with MGUS. Of these, 51 (10%) progressed to multiple myeloma or Waldenström's macroglobulinaemia after a mean interval of 3.8 years; mean follow-up was 7.4 years, median 6 years. The most common immunoglobulin (Ig) class was IgG (55%), followed by IgM (32%) and IgA (13%). MGUS was a highly significant risk factor for developing haematological malignancies and the risk was significantly greater for MG of the IgA class compared with either IgG or IgM.