IgD Myeloma: Clinical Features and Outcome from a Multicenter Retrospective Study in Chinese and Korean of 308 Patients from Asian Myeloma Network (AMN) Project

IgD myeloma is a rare hematologic malignancy for which clinical and biological features and patient outcomes have not been extensively studied. However, previous studies found 3.1% IgD myeloma prevalence in Asian myeloma patients, and with the high incidence of 6%, especially for younger than 50 years with 10.3% in Chinese myeloma patients (Kim K. et al. Am J Hematol. 2014, Lu J. et al. Drug Des Devel Ther. 2016). Therefore, to further assess the frequency and the specific characteristics and evaluate the outcome of patients with IgD myeloma, we carried out a multicenter retrospective study in Chinese and Korean patients from AMN project with diagnosis of IgD myeloma.

A total of 308 patients from 22 centers were included in this analysis. The median age at diagnosis was 56 years with a male predominance (65.70%). Anemia and renal dysfunction were found in 86.7% and 46.2%, respectively. Renal failure is more common at presentation with an increase in serum creatinine (> 2 mg/dL) in more than 10% various series of IgD MM. The bias for λ light chain expression with a reversed light chain ratio is a characteristic feature of IgD MM, which showed 95.79% of patients with IgD λ light chain in Asian patients. DS stage 1, 2, and 3 were showed in 1.30%, 5.84%, and 92.86%, respectively. The chromosomal aberration accounted in 58.14% and t(11;14) was the most common cytogenetic finding (40.57%). Median overall survival (OS) was 39.2 months (95% CI 31.56-41.43). Higher International Staging System (ISS) stages III (62.62%) might be associated with worse survival (P = 0.02), while ISS stages I and II were seen in 16.39% and 20.98%. Patents received with stem cell transplantation showed better survival rates. New drugs including bortezomib, thalidomide, and lenalidomide were used in more than 60% of all patients and affected OS when used as a first-line treatment.

In this multicenter retrospective study from Chinese and Korean IgD myeloma patients, we found that IgD MM more likely presented at advanced stage and showed a more aggressive clinical course. The underlying tumor biology responsible for these differences remains to be determined.