Immunoglobulin D multiple myeloma: response to therapy, survival, and prognostic factors in 75 patients

To analyze the clinical features, outcomes including efficacy of treatment, and prognostic factors of patients with immunoglobulin D multiple myeloma (IgD MM). Seventy-five patients diagnosed with IgD MM were selected from the Korean Myeloma Registry database (www.myeloma.or.kr). Median age was 57 years and the main presenting features were bone pain (77%). Renal function impairment and hypercalcemia were present in 40 (53%) and 20 (27%) patients. Sixty-seven patients (89%) had lambda light chains. Forty-eight patients (64%) were of stage III by International Staging System. Twenty-six patients (53%) had chromosomal abnormalities mostly by conventional cytogenetics. Thirty-nine patients (54%) were treated with vincristine, adriamycin, and dexamethasone chemotherapy; the overall response rate (ORR) of 56%. Sixteen patients (22%) received first-line chemotherapy including new drugs (bortezomib or thalidomide), with an ORR of 81%. At a median follow-up time of 28.6 months, median overall survival (OS) was 18.5 months. Age, extramedullary plasmacytoma, del(13) or hypoploidy, serum β2 microglobulin level, and platelet count were significant prognostic factors for OS. IgD MM is an aggressive disease that is usually detected at an advanced stage. Despite a positive initial response, survival after relapse was dismal. Intensive treatment strategies before and following stem cell transplantation may improve outcomes in younger patients.