Background: In recent decades, the incidence of non-Hodgkin's lymphoma (NHL) has increased in all industrialized countries. Tobacco smoke contains several recognized or putative carcinogenic compounds that differ in concentration depending on which of the two main types, blond or black, is consumed. This investigation sought to evaluate the association between NHL and type of tobacco smoked (blond, black, or mixed), focusing on the Working Formulation (WF) subgroups.
Methods: Reanalysis of Italian data from a recent multicenter population-based case-control study. The 1450 cases of NHL and 1779 healthy controls from 11 Italian areas with different demographic and productive characteristics were included in the study, corresponding to approximately 7 million residents. Odds ratios (ORs) adjusted for age, gender, residence area, educational level, and type of interview were estimated by unconditional logistic regression model.
Results: A statistically significant association [OR = 1.4, 95% confidence interval (CI) 1.1-1.7] was found for blond tobacco exposure and NHL risk. A dose-response relationship was limited to men younger than 52 years (chi(2) for trend = 9.95, P < 0.001). Subjects starting smoking at an early age showed a higher risk in men younger than 65 years, whereas no clear trend was evident for the other age and gender subgroups. The analysis by WF categories showed the highest risks for follicular lymphoma in blond (OR = 2.1, 95% CI 1.4-3.2) and mixed (OR = 1.8, 95% CI 1.1-3.0) tobacco smokers and for large cell within the other WF group (OR = 1.6, 95% CI 1.1-2.4) only for blond tobacco.
Conclusions: Smoking blond tobacco could be a risk factor for NHL, especially follicular lymphoma.