Table 1.

Associations between XRCC genotypes and colorectal adenoma risk in the NHS and the HPFS

GenotypeHPFS
NHS
HPFS + NHS
Cases (%)Controls (%)OR (95% CI)*Cases (%)Controls (%)OR (95% CI)*Cases (%)Controls (%)OR (95% CI)
N376 (34.2)725 (65.8)556 (50.0)557 (50.0)932 (42.1)1282 (57.9)
XRCC2 R188H
    Arg/Arg302 (85.3)582 (84.6)1.00 (ref.)450 (86.9)441 (84.5)1.00 (ref.)751 (86.2)1021 (84.5)1.00 (ref.)
    Arg/His + His/His52 (14.7)106 (15.4)0.96 (0.65-1.42)68 (13.1)81 (15.5)0.81 (0.56-1.18)120 (13.8)187 (15.5)0.88 (0.68-1.13)
XRCC3 A>G 4541
    A/A229 (62.9)467 (65.8)1.00 (ref.)365 (66.6)342 (62.6)1.00 (ref.)593 (65.1)808 (64.4)1.00 (ref.)
    A/G119 (32.7)223 (31.4)1.06 (0.79-1.43)167 (30.5)180 (33.0)0.87 (0.66-1.16)286 (31.4)402 (32.1)0.98 (0.81-1.18)
    G/G16 (4.4)20 (2.8)1.73 (0.84-3.56)16 (2.9)24 (4.4)0.65 (0.31-1.34)32 (3.5)44 (3.5)0.97 (0.61-1.57)
XRCC3 A>G 17893
    A/A180 (49.2)329 (46.7)1.00 (ref.)256 (48.7)250 (47.5)1.00 (ref.)436 (48.9)578 (47.0)1.00 (ref.)
    A/G155 (42.4)303 (43.0)0.89 (0.66-1.20)212 (40.3)222 (42.2)0.87 (0.65-1.17)366 (41.1)524 (42.6)0.93 (0.77-1.12)
    G/G31 (8.5)73 (10.4)0.87 (0.52-1.48)58 (11.0)54 (10.3)1.00 (0.65-1.54)89 (10.0)127 (10.4)0.90 (0.67-1.22)
XRCC3 T241M
    Thr/Thr140 (39.6)257 (37.4)1.00 (ref.)191 (39.6)187 (39.4)1.00 (ref.)331 (39.6)442 (38.1)1.00 (ref.)
    Thr/Met164 (46.3)322 (46.8)0.90 (0.66-1.22)222 (46.1)218 (45.9)1.11 (0.82-1.52)385 (46.1)540 (46.5)0.95 (0.78-1.16)
    Met/Met50 (14.1)109 (15.8)0.87 (0.57-1.33)69 (14.3)70 (14.8)1.03 (0.66-1.63)119 (14.3)179 (15.4)0.89 (0.68-1.17)
  • Abbreviations: OR, odds ratio; CI, confidence interval.

  • * Conditional logistic regression adjusted for matching factors and family history of colorectal cancer, pack-years smoking, aspirin use, body mass index, postmenopausal hormone use (NHS), and intake of folic acid and alcohol.

  • Unconditional logistic regression adjusted for age, sex, and family history of colorectal cancer.