DNA repair capacity and lung cancer risk in never smokers.
Besides secondhand smoke exposure, few other risk factors for lung cancer in lifetime never smokers have been identified. We present the estimates of lung cancer risk associated with suboptimal DNA repair capacity (DRC) measured by the host-cell reactivation assay in lifetime never smokers using data from 219 cases and 309 matched controls enrolled in a case-control study. Suboptimal DRC level (below the control median) conferred a significantly increased lung cancer risk in never smokers [odds ratio, 1.92; 95% confidence interval (95% CI), 1.3-2.9; P = 0.0024]. There was a 3.38-fold risk for individuals with DRC below the first quartile (95% CI, 1.8-6.3) compared with individuals with DRC above the third quartile. Secondhand smoke exposure in individuals with DRC below the control median was associated with a 3.81-fold risk of lung cancer (95% CI, 2.3-6.4). A 2.49-fold (95% CI, 1.1-5.6) risk was noted for the joint effects of lung cancer family history in first-degree relatives and suboptimal DRC. Relatives of probands (cases and controls) with lowest DRC (below the first quartile) were significantly more likely to be diagnosed with lung cancer (odds ratio, 2.69; 95% CI, 1.1-6.7) compared with relatives of probands with the most proficient DRC (above the third quartile). Relatives of probands with suboptimal (below the control median) versus proficient DRC also had an earlier age at diagnosis with lung cancer, although the only statistically significant difference was in female relatives (55.4 versus 67.7 years; P = 0.03).
Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA. oygorlov@mdanderson.org
Olga Y
OY
Gorlova
Shih-Feng
SF
Weng
Yiqun
Y
Zhang
Christopher I
CI
Amos
Margaret R
MR
Spitz
Qingyi
Q
Wei
D000368:Aged; D016022:Case-Control Studies; D016001:Confidence Intervals; D004260:DNA Repair; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking; D018709:Statistics, Nonparametric; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D014028:Tobacco Smoke Pollution