Type 2 diabetes and risk of non-Hodgkin lymphoma and multiple myeloma: a pooled analysis

Prior studies suggest positive associations of type 2 diabetes (T2D) with risk of non-Hodgkin lymphoma (NHL) and multiple myeloma (MM), but few studies had sufficient statistical power to evaluate associations for specific histological subtypes.

We pooled data from the Cancer Prevention Study-II Nutrition Cohort, California Teachers' Study, Health Professionals Follow-up Study, Nurses' Health Study (NHS), and NHSII cohorts and a sample of Kaiser Permanente Southern California members (585,114 total study participants). We confirmed incident diagnoses of NHL and MM using medical records or cancer registries. T2D history was assessed by self-report or clinical diagnosis. We estimated the associations of T2D history (yes/no) and T2D duration with risk of overall NHL, NHL subtypes, or MM using multivariable Cox regression models adjusted for age, sex, cohort, follow-up year, race, education, smoking, and body mass index.

We confirmed 11,478 NHL and 2,783 MM diagnoses over a median follow-up of 20 years. T2D history was not associated with overall NHL risk but was positively associated with risk of diffuse large B-cell lymphoma (DLBCL; hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 1.04 to 1.28) and MM (HR = 1.20, 95% CI = 1.07 to 1.35) and inversely associated with risk of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (HR = 0.45, 95% CI = 0.27 to 0.75), T-cell NHL (HR = 0.78, 95% CI = 0.62 to 0.97), and mycosis fungoides/Sézary syndrome (HR = 0.67, 95% CI = 0.46 to 0.98). T2D duration was positively associated with risk of DLBCL and MM.

Our findings suggest a role for T2D in DLBCL and MM; thus, T2D prevention may be important in reducing their incidence. Some unexpected inverse associations require further investigation.