Association between smoking and deaths due to colorectal malignant carcinoma: a national population-based case-control study in China.
BACKGROUND
This study explored the association between smoking and colorectal malignant carcinoma (CRC) in the Chinese population at the national level for the first time.


METHODS
In the China Nationwide Retrospective Mortality Survey conducted during 1989-1991, 12,942 CRC cases among 1,136,336 all-cause deaths aged ≥30 years were randomly assigned 25,884 control interviews from 325,255 surviving spouses of all-cause deaths across 103 urban and rural areas.


RESULTS
Compared with non-smokers, smoking significantly increased the risk of CRC-specific mortality by 9.8% (odds ratio (OR)=1.098, 95% confidence interval (CI)=1.046-1.153) adjusted for sex, age, and residence. There were significant dose-response relationships between smoking and CRC, such as smoking years, cigarettes smoked daily, and age at onset of smoking. Long-term heavy smokers aged ≥50 years with ≥30 smoking years and ≥20 cigarettes daily had an excess risk of CRC deaths of 30.2% (OR=1.302, 95% CI=1.214-1.397). The strongest association between these smoking variables, such as long-term heavy smokers (OR=1.604, 95% CI=1.341-1.919), and CRC was observed among rural men.


CONCLUSIONS
Quitting smoking at any time would likely be beneficial to CRC prevention. Long-term heavy smokers and rural men should be viewed as special targets for smoking prevention and cessation programs.
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
L
L
Hou
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
J
J
Jiang
Cancer Institute & Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China.
B
B
Liu
School of Public Health, State University of New York, New York, NY, USA.
P C
PC
Nasca
Cancer Institute & Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China.
Y
Y
Wu
Cancer Institute & Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China.
X
X
Zou
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
W
W
Han
Cancer Institute & Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China.
Y
Y
Chen
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
B
B
Zhang
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
F
F
Xue
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences/School of Basic Medicine Peking Union Medical College, Beijing, China.
H
H
Pang
Cancer Institute & Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing, China.
J
J
Li
D016022:Case-Control Studies; D002423:Cause of Death; D002681:China / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012306:Risk; D012424:Rural Population; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology / Q000401:mortality*