Alcohol consumption and risk of non-Hodgkin lymphoma: a pooled analysis.
BACKGROUND
Previous epidemiological studies of the relation between alcohol consumption and risk of non-Hodgkin lymphoma (NHL) have been inconsistent, probably because of small sample sizes of individual studies that result from stratification by NHL subtype and type of alcoholic beverage. We aimed to assess the role of alcohol consumption in NHL with sufficient sample size to analyse by both type of alcoholic beverage and disease subtype.


METHODS
We obtained original data from nine case-control studies from the USA, UK, Sweden, and Italy in the International Lymphoma Epidemiology Consortium (InterLymph), yielding a pooled study population of 15 175 individuals (6492 cases and 8683 controls). We derived odds ratios (OR) and 95% CI from unconditional logistic regression models, controlling for study centre and other confounding factors. Heterogeneity between studies was assessed by comparison of results from joint fixed-effects logistic regression and two-stage random-effects logistic regression, and by calculation of Wald chi(2) statistics.


RESULTS
People who drank alcohol had a lower risk of NHL than did non-drinkers (OR 0.83 [95% CI 0.76-0.89]). Compared with non-drinkers, risk estimates were lower for current drinkers than for former drinkers (0.73 [0.64-0.84] vs 0.95 [0.80-1.14]), but risk did not decrease with increasing alcohol consumption. The protective effect of alcohol did not vary by beverage type, but did change with NHL subtype. The lowest risk estimates were recorded for Burkitt's lymphoma (0.51 [0.33-0.77]).


CONCLUSIONS
People who drink alcoholic beverages might have a lower risk of NHL than those who do not, and this risk might vary by NHL subtype. Further study designs are needed to determine whether confounding lifestyle factors or immunomodulatory effects of alcohol explain this association.
Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT, USA.
Lindsay M
LM
Morton
Tongzhang
T
Zheng
Theodore R
TR
Holford
Elizabeth A
EA
Holly
Brian C H
BC
Chiu
Adele Seniori
AS
Costantini
Emanuele
E
Stagnaro
Eleanor V
EV
Willett
Luigino
L
Dal Maso
Diego
D
Serraino
Ellen T
ET
Chang
Wendy
W
Cozen
Scott
S
Davis
Richard K
RK
Severson
Leslie
L
Bernstein
Susan T
ST
Mayne
Fred R
FR
Dee
James R
JR
Cerhan
Patricia
P
Hartge
D000293:Adolescent; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors