A nationwide study of patients with monoclonal gammopathy of undetermined significance with a 10-year follow-up in South Korea

Ka-Won Kang,Hwa Jung Sung,Yong Park,Byung-Hyun Lee,Chul Won Choi,Se Ryeon Lee,Byung Soo Kim,Eun Sang Yu,Dae Sik Kim,Min Ji Jeon,Ji Eun Song

doi:10.1038/s41598-021-97664-y

Abstract

In clinical practice, most patients with monoclonal gammopathy of undetermined significance (MGUS) undergo long-term follow-up without disease progression. There is insufficient real-world data about how closely and whether anything other than disease progression should be monitored. Herein, we performed a nationwide study of 470 patients with MGUS with a 10-year follow-up to determine the patterns of disease progression and other comorbidities. During the follow-up period, 158 of 470 patients with MGUS (33.62%) progressed to symptomatic monoclonal gammopathies. Most of these were multiple myeloma (134/470 patients, 28.51%), and those diagnosed within 2 years after diagnosis of MGUS was high. Approximately 30–50% of patients with MGUS had hypertension, diabetes, hyperlipidemia, and osteoarthritis at the time of diagnosis, and these comorbidities were newly developed during the follow-up period in approximately 50% of the remaining patients with MGUS. Approximately 20–40% of patients with MGUS have acute or chronic kidney failure, thyroid disorders, disc disorders, peripheral neuropathy, myocardial infarction, stroke, and heart failure during the follow-up period. Altogether, when MGUS is diagnosed, close follow-up of the possibility of progression to multiple myeloma is required, especially within 2 years after diagnosis; simultaneously, various comorbidities should be considered and monitored during the follow-up of patients with MGUS. Continuous research is needed to establish appropriate follow-up guidelines.

Highlights

Monoclonal gammopathy of undetermined significance (MGUS) is defined as serum monoclonal protein level < 3 g/dL, bone marrow plasma cells < 10%, and absence of end-organ damage, or other lymphoproliferative malignancies[1,2]
A total of 470 patients were analyzed in this study, after excluding patients with MM, plasma cell leukemia (PCL), plasmacytoma, Waldenström macroglobulinemia (WM), amyloidosis, lymphoproliferative diseases, and hematologic malignancies at the time of diagnosis of monoclonal gammopathy of undetermined significance (MGUS) (Supplementary Table 1)
During a 10-year follow-up of patients with MGUS, 158 of 470 patients (33.62%) progressed to symptomatic monoclonal gammopathies. Most of these were MM (134/470 patients, 28.51%), and the number of cases diagnosed within 2 years after the diagnosis of MGUS was high

Summary

Introduction

Monoclonal gammopathy of undetermined significance (MGUS) is defined as serum monoclonal protein level < 3 g/dL, bone marrow plasma cells < 10%, and absence of end-organ damage (e.g., hypercalcemia, renal insufficiency, anemia, and bone lesions), or other lymphoproliferative malignancies[1,2]. To detect disease progression, the current guidelines recommend the quantification of monoclonal protein along with monitoring of related symptoms in patients with MGUS at 3–6 month intervals for the first 1–2 years, and at 6–24 months intervals if s table[4,6,7,8]. Progression to symptomatic monoclonal gammopathy is an important cause of death in patients with MGUS, it does not entirely explain the shorter overall survival time[18]. Other comorbidities may be associated with shorter overall survival times in patients with MGUS11,19,20, it is necessary to reconsider whether it is sufficient to focus solely on disease progression during follow-up and testing according to the recommendations of the guidelines mentioned above. This study aimed to determine the occurrence patterns of disease progression and other comorbidities during a 10-year follow-up period in the real world

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Conclusion