Obesity and non-Hodgkin lymphoma survival in an ethnically diverse population: the Multiethnic Cohort study

Purpose

Obesity increases mortality for several malignancies, but for non-Hodgkin lymphoma (NHL), the association between body mass index (BMI) and survival is unclear. We examined the association of pre-diagnostic BMI with overall and NHL-specific survival in the multiethnic cohort (MEC) study of African Americans, Native Hawaiians, Japanese Americans, Latinos, and Caucasians.

Methods

MEC participants free of NHL at cohort entry and diagnosed with NHL during follow-up were included in the analyses (n = 1,331). BMI was based on self-reported weight and height at cohort entry and after 6.1 years of cohort entry. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95 % confidence intervals (CI) with BMI as time-varying exposure in relation to all-cause and NHL-specific mortality while adjusting for known confounders.

Results

The mean age at NHL diagnosis was 70.5 (range 45–89) years. After a mean follow-up of 4.3 ± 3.5 years, 667 deaths including 450 NHL-specific deaths occurred. In multivariable models, obese patients (BMI ≥30.0 kg/m²) had higher all-cause (HR 1.46, 95 % CI 1.13–1.87) and NHL-specific (HR 1.77, 95 % CI 1.30–2.41) mortality compared with patients with high-normal BMI (22.5–24.9 kg/m²). For overweight patients (BMI = 25.0–29.9 kg/m²), the respective HRs were 1.21 (95 % CI 0.99–1.49) and 1.36 (95 % CI 1.06–1.75). Cases with low-normal BMI (<22.5 kg/m²) experienced a significant 45 % higher all-cause and a 40 % higher NHL-specific mortality. After stratification by NHL type, the adverse effect of BMI was stronger for chronic lymphocytic leukemia/small lymphocytic lymphoma than for diffuse large B cell lymphoma and follicular lymphoma.

Conclusions

Pre-diagnostic BMI may be a suitable prognostic marker for NHL patients.