Joint effects of environmental exposures and familial susceptibility to lung cancer in Chinese never smoking men and women.
OBJECTIVE
Previous epidemiological studies had limited power to investigate the joint effects of individual environmental risk factors and familial susceptibility to lung cancer. This study aimed to address this shortcoming.


METHODS
We recruited 345 never smoking lung cancer cases and 828 community referents. We developed a collective environmental exposure index by assigning a value of 1 to subjects at high risks regarding environmental risk factors and 0 otherwise, and then summed over using weights equivalent to the excess odds ratio. Potential additive and multiplicative interactions between environmental exposure index and family cancer history were examined.


RESULTS
Compared with "low environmental exposure and without family cancer history", the odds ratio was 6.80 (95% confidence interval = 3.31-13.98) for males who had high environmental exposures but without family cancer history, whereas it increased to 30.61 (95% confidence interval = 9.38-99.87) if they also had a positive family history. The corresponding associations became weaker in never smoking females. No multiplicative interaction was observed for both genders and an additive interaction was restricted among males.


CONCLUSIONS
This study developed a novel environmental exposure index that offers sufficient interest deserving further studies on the interactions between environmental exposures and familial susceptibility to lung cancer risk.
*Division of Occupational and Environmental Health, JC School of Public Health and Primary Care, The Chinese University of Hong Kong, HKSAR, China; †Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD; and ‡Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, HKSAR, China.
Lap Ah
LA
Tse
Ignatius Tak-Sun
IT
Yu
Nathaniel
N
Rothman
Bu-Tian
BT
Ji
Hong
H
Qiu
Xiao-Rong
XR
Wang
Wei
W
Hu
Joseph Siu-Kie
JS
Au
Qing
Q
Lan
D000230:Adenocarcinoma / Q000453:epidemiology* / Q000235:genetics*; D016902:Air Pollution, Indoor; D003296:Cooking; D004032:Diet; D019587:Dietary Supplements; D004781:Environmental Exposure; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D008460:Meat; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D012906:Smoke; D014675:Vegetables; D014815:Vitamins
D012906:Smoke; D014815:Vitamins