Comorbid Diabetes Does Not Impact the Survival of Patients with Multiple Myeloma

For patients with multiple myeloma (MM), comorbid type II diabetes mellitus (DM) has leaded additional consideration and complications. Preceding DM in MM patients may have lead to end-organ damage involving cardiovascular, renal and nervous systems, and the use of glucocorticoids - the mainstay of anti-myeloma agents - further impairs glycemic control. However, it is not well studied at present whether comorbid DM itself will influence clinical features and prognosis of MM patients. Methods. Patients who were newly diagnosed in Taipei Veterans General Hospital between 1996 and 2007 were enrolled. Data of clinical features, comorbidities, and laboratory tests at diagnosis, treatment modalities, and survival at last follow up were collected. MM patients with or without DM was compared in terms of clinical/laboratory tests and outcome. Results. There were 389 MM patients (M/F=288/101, 74% vs. 26%) with median age of 71 years, with the features summarized in the Table. The immunophenotypes consisted of IgG (194, 49.9%), IgA (113, 29%), and light chain diseases (LCD) (67, 17.2%). Clinical stages included Durie-Salmon (DS) stage I/II/III = 7.2%/20.1%/72.7% and International Staging System (ISS) stage I/II/III = 14.5%/29.3%/56.2%. Serum Cr > 2.0 mg/dL at diagnosis was noted in 34%. Sixty patients (15.4% of 389) had DM preceding the diagnosis of MM. There was no statistical difference of median age, gender distribution, DS stages, and renal impairment when comparing MM patients with or without comorbid DM.MM patients with comorbid DM were associated with a lower prevalence of IgA-type diseases (with vs. without DM= 17% vs. 32%, P=0.094), an elevated serum beta-2 microglobulin >5 mg/L (with vs. without DM = 75% vs. 52%, P=.006), and ISS-stage III disease (with vs. without DM = 75% vs. 53%, P=.005). In terms of anti-myeloma therapy, the proportion of MM patients with or without DM who once received thalidomide, bortezomib and high-dose chemotherapy plus stem cell transplantation (HDT and SCT), and bisphosphonates were similar. The median overall survival (OS) of all patients was 20.5 months. The OS was well correlated with ISS stages (I vs. II vs. III = 51.2 vs. 27.2 vs. 13.4 months, P<0.001) but was not with comorbid DM. Conclusions. Comorbid DM was present in up to 15% of MM patients, and was more frequently associated with elevated serum beta-2 microglobulin (>5 mg/L) and ISS-stage III diseases; however, comorbid DM did not significantly influence the OS. Therefore, comorbid DM itself should not be considered as a contraindication of aggressive anti-myeloma treatments at present.

No relevant conflicts of interest to declare.