Approaching hypercalcemia in monoclonal gammopathy of undetermined significance: insights from the iStopMM screening study
Abstract
Abstract Hypercalcemia in monoclonal gammopathy of undetermined significance (MGUS) presents a clinical challenge because it may indicate progression to multiple myeloma (MM) but could also be due to a multitude of unrelated disorders. To inform the approach to this clinical challenge, we conducted a nested cohort study within the Iceland Screens, Treats, or Prevents Multiple Myeloma screening study. Of the 75 422 Icelanders aged 40 years and above who underwent screening for MGUS, we included 2546 with MGUS who were in active follow-up, including regular serum calcium measurements. In total, 191 individuals (7.5%) had hypercalcemia detected at least once, of whom 93 had persistent hypercalcemia (48.7%). MM was found in 3 participants with persistent hypercalcemia (3.2%); all had concurrent bone disease and other end-organ damage. The most common causes of hypercalcemia were primary hyperparathyroidism (56.0%) and malignancies other than MM (16.0%). In this first comprehensive study on hypercalcemia in MGUS, we observed that hypercalcemia rarely indicated MGUS progression and never in the absence of other symptoms of MM. More than half of hypercalcemia cases were transient, and the underlying causes were similar to those in the general population. We conclude that hypercalcemia in MGUS should be approached in the same way as in those without MGUS.
Article Details
Authors (23)
Ástrún Helga Jónsdóttir
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Helga Ágústa Sigurjónsdóttir
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Sigrún Thorsteinsdóttir
Thorir Einarsson Long
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Ingigerður Sólveig Sverrisdóttir
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Elias Eythorsson
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Jón Þórir Óskarsson
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Runolfur Palsson
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Olafur Skuli Indridason
8Department of Nephrology, Landspítali University Hospital, Reykjavik, Iceland
Brynjar Viðarsson
9Department of Hematology Landspítali University Hospital, Reykjavik, Iceland
Pall Torfi Onundarson
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Ísleifur Ólafsson
7Department of Clinical Biochemistry and Hematology, Landspítali University Hospital, Reykjavik, Iceland
Ingunn Þorsteindóttir
7Department of Clinical Biochemistry and Hematology, Landspítali University Hospital, Reykjavik, Iceland
Bjarni A. Agnarsson
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Margrét Sigurðardóttir
10Department of Pathology, Landspítali University Hospital, Reykjavik, Iceland
Ásbjörn Jónsson
11Department of Radiology, Akureyri Hospital, Akureyri, Iceland
Malin Hultcrantz
1Memorial Sloan Kettering Cancer Center, Myeloma Service, Department of Medicine, New York, United States
Brian G. M. Durie
Stephen Harding
2The Binding Site (part of Thermo Fisher Scientific), Birmingham, United Kingdom
Ola Landgren
Thorvardur Jon Love
1Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Sigurður Yngvi Kristinsson
Sæmundur Rögnvaldsson