biostudies-literatureJonsdottir AHEuropean Research CouncilNCI NIH HHS970-974https://www.ebi.ac.uk/biostudies/studies/S-EPMC12509072biostudies-literatureUnknown145(9)<h4>Abstract</h4>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 cBloodApproaching hypercalcemia in monoclonal gammopathy of undetermined significance: insights from the iStopMM screening study.PMC12509072P30 CA008748P30 CA240139716677Kristinsson SYSverrisdottir ISLandgren ODurie BGMRognvaldsson SJonsdottir AHIndridason OSOskarsson JÞSigurjonsdottir HAEythorsson ESigurðardottir MÞorsteindottir IJonsson ALove TJLong TEViðarsson BOlafsson IPalsson ROnundarson PTHultcrantz MThorsteinsdottir SAgnarsson BAHarding SfalseApproaching hypercalcemia in monoclonal gammopathy of undetermined significance: insights from the iStopMM screening study.<h4>Abstract</h4>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 c2025-01-01T00:00:00Z2025 Feb2026-06-04T07:04:54.192Z2026-05-06T03:13:15.092ZS-EPMC125090723970050610.1182/blood.2024025624