Baseline TM  Net BPDE-induced TM  Net γ radiation-induced TM N Mean  (SD) N Mean (SD) N Mean  (SD) Overall Cases 172 1.78(1.01) 143 0.88(0.94) 167 1.80(1.47) Controls 154 1.60(1.03) 120 0.62(0.77) 146 1.60(1.25) Pa   0.051   0.031   0.318 Characteristicsin controls Sex Male 137 1.54(1.01) 106 0.57 ( 0.69) 130 1.60(1.30) Female 17 2.10(1.09) 14 1.02(1.18) 16 1.62(0.88) Pa   0.010   0.233   0.483 Age <62 71 1.53(0.94) 53 0.50(0.70) 67 1.62(1.30) ≥62 83 1.66(1.11) 67 0.72(0.81) 79 1.58(1.22) Pa   0.551   0.247   0.874 Smoking status Never 74 1.49(0.93) 55 0.52(0.74) 68 1.57(1.21) Ever 80 1.71(1.11) 65 0.71(0.79) 78 1.63(1.30) Pa   0.280   0.117   0.627 GERD No 128 1.64(1.09) 100 0.59(0.70) 122 1.58(1.24) Yes 26 1.40(0.69) 20 0.77(1.04) 24 1.73(1.36) Pa   0.537   0.379   0.675

Table 2: DNA damage in overall cases and controls, and correlations of DNA damage and selected host characteristics in control participants. aWilcoxon rank-sum test was used to evaluate the difference in DNA damages among subgroups. Note: some blood samples were not assayed for mutagen-induced DNA damage.