Table 4.

Association between the type of Ki-ras mutation and selected demographic and clinicopathologic characteristics

No. of subjectsMutation
Affected codon
No Ki-ras mutation, no. (%)Ki-ras mutation, no. (%)G-to-A transition, n (%)G-to-T transversion, no. (%)G-to-C transversion, no. (%)Codon 12, no. (%)Codon 13, no. (%)
Age (y)
    <66389349 (89.7)40 (10.3)18 (4.6)20 (5.1)2 (0.5)31 (8.0)9 (2.3)
    ≥66509417 (81.9)92 (18.1)47 (9.2)39 (7.7)9 (1.8)80 (15.7)16 (3.1)
    P*0.0010.010.120.080.00050.34
Adenoma location
    Proximal colon293261 (89.1)32 (10.9)18 (6.1)11 (3.8)3 (1.0)28 (9.6)5 (1.7)
    Distal colon437377 (86.3)60 (13.7)28 (6.4)27 (6.2)6 (1.4)48 (11.0)12 (2.8)
    Rectum8465 (77.4)19 (22.6)7 (8.3)11 (13.1)0 (0.0)17 (20.2)2 (2.4)
    P0.030.590.00850.790.030.64
Histology
    Tubular657604 (91.9)53 (8.1)23 (3.5)23 (3.5)6 (0.9)45 (6.9)9 (1.4)
    Tubulovillous208142 (68.3)66 (31.7)33 (15.9)31 (14.9)5 (2.4)56 (26.9)12 (5.8)
    Villous3018 (60.0)12 (40.0)9 (30.0)4 (13.3)0 (0.0)9 (30.0)4 (13.3)
    P<0.0001<0.0001<0.00010.10<0.0001<0.0001
Adenoma size (cm)
    <1547491 (89.8)56 (10.2)25 (4.6)27 (4.9)5 (0.9)47 (8.6)10 (1.8)
    ≥1349274 (78.5)75 (21.5)39 (11.2)32 (9.2)6 (1.7)63 (18.1)15 (4.3)
    P<0.0001<0.00010.0050.22<0.00010.01
Dysplasia
    Low grade675601 (89.0)74 (11.0)34 (5.0)33 (4.9)9 (1.3)59 (8.7)16 (2.4)
    High grade210157 (74.8)53 (25.2)29 (13.8)23 (11.0)2 (1.0)47 (22.4)9 (4.3)
    P<0.0001<0.00010.00041.00<0.00010.07
Advanced adenoma
    No429401 (93.5)28 (6.5)11 (2.6)10 (2.9)3 (0.7)25 (5.8)3 (0.7)
    Yes469365 (77.8)104 (22.2)54 (11.5)41 (10.1)8 (1.7)86 (18.3)22 (4.7)
    P<0.0001<0.0001<0.00010.13<0.0001<0.0001
  • NOTE: Missing data for location and histology (3), missing data for size (2), and missing data for dysplasia (13).

  • * Compared with Ki-ras mutation negative based on a Fisher's exact test.

  • Includes one or more of the following characteristics: tubulovillous or villous histology, ≥1 cm in size, or HGD.