Objectives: To investigate potential risk factors (personal characteristics, lifestyle, and environmental factors) of non-Hodgkin lymphoid neoplasms (NHLN), including lymphomas and lymphocytic leukemia, according to the World Health Organization classification.
Materials and Methods: The investigation was a hospital-based case-control study consisting of 649 confirmed NHLN cases and 1298 individually gender-age-matched patient controls at 25 hospitals in Shanghai. A 17-page questionnaire was used to obtain information on demographics, medical history, family history, lifestyle risk factors, employment history, residential history, and occupational and non-occupational exposures. Risk estimates were calculated using conditional logistic regression models.
Results: Potential risk factors of NHLN (all subtypes combined) or individual subtypes included low-level education, home or workplace renovation, living on a farm, planting crops, and raising livestock or animals. Some risk factors applied to all or most subtypes (such as lowlevel education, living on a farm, and raising livestock or animals), whereas others did not (such as the use of traditional Chinese medicines, which was associated with a reduced risk). Blood transfusions, hair dyes, or living near high-voltage power lines were not associated with an increased risk.
Conclusions: The study identified a number of risk factors for NHLN overall and specific subtypes. Some risk factors were subtype-specific. The difference in risk by subtype underscores the etiologic commonality and heterogeneity of NHLN subtypes.
From the Applied Health Sciences (Dr Wong, Ms Harris), San Mateo, Calif; School of Public Health (Dr Wong), Chinese University of Hong Kong, Hong Kong, China; Department of Preventive Medicine (Dr Wong), University of Hong Kong, Hong Kong, China; Fudan University School of Public Health (Dr Wong, Mr Wang, Dr Fu), Shanghai, China; and University of California, School of Medicine, Department of Epidemiology and Biostatistics (Ms Harris), San Francisco, Calif.
Address correspondence to: Otto Wong, ScD, Applied Health Sciences, P.O. Box 2078, San Mateo, California 94401; E-mail: firstname.lastname@example.org.