Cigarette smoking and adenocarcinomas of the esophagus and esophagogastric junction: a pooled analysis from the international BEACON consortium.
BACKGROUND
Previous studies that showed an association between smoking and adenocarcinomas of the esophagus and esophagogastric junction were limited in their ability to assess differences by tumor site, sex, dose-response, and duration of cigarette smoking cessation.


METHODS
We used primary data from 10 population-based case-control studies and two cohort studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium. Analyses were restricted to white non-Hispanic men and women. Patients were classified as having esophageal adenocarcinoma (n = 1540), esophagogastric junctional adenocarcinoma (n = 1450), or a combination of both (all adenocarcinoma; n = 2990). Control subjects (n = 9453) were population based. Associations between pack-years of cigarette smoking and risks of adenocarcinomas were assessed, as well as their potential modification by sex and duration of smoking cessation. Study-specific odds ratios (ORs) estimated using multivariable logistic regression models, adjusted for age, sex, body mass index, education, and gastroesophageal reflux, were pooled using a meta-analytic methodology to generate summary odds ratios. All statistical tests were two-sided.


RESULTS
The summary odds ratios demonstrated strong associations between cigarette smoking and esophageal adenocarcinoma (OR = 1.96, 95% confidence interval [CI] = 1.64 to 2.34), esophagogastric junctional adenocarcinoma (OR = 2.18, 95% CI = 1.84 to 2.58), and all adenocarcinoma (OR = 2.08, 95% CI = 1.83 to 2.37). In addition, there was a strong dose-response association between pack-years of cigarette smoking and each outcome (P < .001). Compared with current smokers, longer smoking cessation was associated with a decreased risk of all adenocarcinoma after adjusting for pack-years (<10 years of smoking cessation: OR = 0.82, 95% CI = 0.60 to 1.13; and > or =10 years of smoking cessation: OR = 0.71, 95% CI = 0.56 to 0.89). Sex-specific summary odds ratios were similar.


CONCLUSIONS
Cigarette smoking is associated with increased risks of adenocarcinomas of the esophagus and esophagogastric junction in white men and women; compared with current smoking, smoking cessation was associated with reduced risks.
Cook
Michael B
MB
Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health/DHHS, 6120 Executive Blvd., Bethesda, MD 20852-7234, USA. michael.cook@nih.gov
Kamangar
Farin
F
Whiteman
David C
DC
Freedman
Neal D
ND
Gammon
Marilie D
MD
Bernstein
Leslie
L
Brown
Linda M
LM
Risch
Harvey A
HA
Ye
Weimin
W
Sharp
Linda
L
Pandeya
Nirmala
N
Webb
Penelope M
PM
Wu
Anna H
AH
Ward
Mary H
MH
Giffen
Carol
C
Casson
Alan G
AG
Abnet
Christian C
CC
Murray
Liam J
LJ
Corley
Douglas A
DA
Nyrén
Olof
O
Vaughan
Thomas L
TL
Chow
Wong-Ho
WH
D000230:Adenocarcinoma / Q000453:epidemiology / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D004943:Esophagogastric Junction; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012107:Research Design; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology*; D013997:Time Factors