Table 3.

Risk of colorectal cancer associated with XPC genotype stratified by cancer location

PolymorphismNo. PYColorectal cancer
Colon cancer
Proximal colon cancer
Distal colon cancer
Rectal cancer
No. casesRR (95% CI)No. casesRR (95% CI)No. casesRR (95% CI)No. casesRR (95% CI)No. casesRR (95% CI)
R492H
RR25,7181921.01511.0821.0561.0411.0
    RH3,455401.71 (1.16-2.52)331.80 (1.18-2.75)161.60 (0.91-2.83)172.48 (1.38-4.45)71.37 (0.61-3.09)
    HH6323.90 (0.61-25.1)*25.01 (0.78-32.4)*14.54 (0.44-46.9)*16.77 (0.66-69.1)*0
    Ptrend0.0030.0020.060.00080.51
A499V
    AA16,9831231.0941.0491.0351.0291.0
    AV10,515851.13 (0.84-1.54)711.24 (0.88-1.73)421.41 (0.91-2.18)261.21 (0.72-2.06)140.79 (0.41-1.52)
    VV1,399110.93 (0.46-1.86)80.89 (0.40-1.96)10.22 (0.03-1.61)72.09 (0.87-5.06)31.07 (0.31-3.67)
    Ptrend0.680.500.860.140.71
R687R
    GG15,7841541.01271.0721.0491.0271.0
    AG11,327710.63 (0.47-0.86)510.55 (0.39-0.78)250.47 (0.30-0.76)200.56 (0.33-0.96)201.03 (0.57-1.85)
    AA2,096211.06 (0.63-1.77)160.98 (0.55-1.74)70.75 (0.33-1.68)71.12 (0.49-2.57)51.43 (0.54-3.81)
    Ptrend0.130.050.020.310.60
K939Q
    KK9,791811.0621.0271.0301.0191.0
    KQ14,2771100.94 (0.68-1.29)880.98 (0.69-1.40)511.30 (0.80-2.12)300.69 (0.41-1.17)220.80 (0.43-1.49)
    KQ5,168531.19 (0.80-1.76)431.25 (0.81-1.93)261.74 (0.98-3.08)150.91 (0.48-1.75)100.97 (0.44-2.12)
    Ptrend0.500.380.060.580.82
  • * Because the cell counts are small, the normal approximation cannot be used. The true confidence intervals are slightly wider than the confidence intervals presented above.