this work was supported the early detection research network of the national cancer institute , national institutes of health ( u01 ca111219 to zl , tp - e , and gr ) and the flight attendant medical research institute , florida ( part of a center of excellence award , 032001 to zl and tp - e ) .
 only a minority of smokers develop lung cancer , possibly due to genetic predisposition , including dna repair deficiencies . 
 to examine whether inter - individual variations in dna repair activity of n - methylpurine dna glycosylase ( mpg ) are associated with lung cancer , we conducted a blinded , population - based , case  control study with 100 lung cancer case patients and 100 matched control subjects and analyzed the data with conditional logistic regression . 
 all statistical tests were two - sided . 
 mpg enzyme activity in peripheral blood mononuclear cells from case patients was higher than in control subjects , results opposite that of 8-oxoguanine dna glycosylase ( ogg1 ) dna repair enzyme activity . for lung cancer associated with one standard deviation increase in mpg activity , 
 the adjusted odds ratio was 1.8 ( 95% confidence interval [ ci ] = 1.2 to 2.6 ; p = .006 ) . 
 a combined mpg and ogg1 activities score was more strongly associated with lung cancer risk than either activity alone , with an odds ratio of 2.3 ( 95% ci = 1.4 to 3.6 ; p < .001 ) . 
 these results form a basis for a future panel of risk biomarkers for lung cancer risk assessment and prevention . 
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