Table 2.

Clinical, pathologic, and molecular features of colorectal cancer according to PIK3CA mutation status

PIK3CA mutation present
TotalPIK3CA wild typeOnly in exon 9P (exon 9 vs. exon 20)Only in exon 20In both exon 9 and exon 20P (across all categories)
FeatureNo. (%)No. (%)No. (%)No. (%)No. (%)
Total no.1,170981109737
Sex0.880.26
 Male, (HPFS)536 (46)439 (45)56 (51)36 (49)5 (71)
 Female, (NHS)634 (54)542 (55)53 (49)37 (51)2 (29)
Mean age at diagnosis (y) ± SD68.7 ± 8.768.6 ± 8.769.4 ± 8.90.9468.3 ± 9.075.6 ± 10.00.95
Year of diagnosis0.760.92
 Before 1997501 (43)424 (43)43 (39)31 (43)3 (43)
 1997 or after669 (57)557 (57)66 (61)42 (57)4 (57)
Family history of colorectal cancer in first degree relatives0.190.030
 Absent951 (81)804 (82)90 (83)54 (74)3 (43)
 Present219 (19)177 (18)19 (17)19 (26)4 (57)
Tumor location0.800.19
 Rectum258 (22)230 (24)17 (16)10 (14)1 (14)
 Distal colon359 (31)300 (31)32 (29)25 (34)2 (29)
 Proximal colon546 (47)444 (45)60 (55)38 (52)4 (57)
Disease stage0.0930.23
 I282 (24)231 (24)33 (30)15 (21)3 (43)
 II327 (28)270 (28)28 (26)28 (38)1 (14)
 III308 (26)264 (27)24 (22)19 (26)1 (14)
 IV151 (13)124 (13)15 (14)10 (14)2 (29)
 Unknown102 (9)92 (9)9 (8)1 (1)0 (0)
Tumor grade0.0670.27
 Low1,052 (91)880 (90)102 (94)63 (86)7 (100)
 High111 (9)95 (10)6 (6)10 (14)0 (0)
MSI status0.00070.0050
 MSI low/MSS978 (85)820 (85)100 (92)52 (72)6 (86)
 MSI high176 (15)146 (15)9 (8)20 (28)1 (14)
CIMP status0.0280.025
 CIMP low/0906 (83)762 (83)88 (87)52 (73)4 (57)
 CIMP high187 (17)152 (17)13 (13)19 (27)3 (43)
BRAF status0.0300.15
 Wild type993 (85)831 (85)99 (91)57 (79)6 (86)
 Mutant171 (15)145 (15)10 (9)15 (21)1 (14)
KRAS status0.290.0001
 Wild type747 (64)659 (67)48 (44)38 (53)2 (29)
 Mutant418 (36)318 (33)61 (56)34 (47)5 (71)
Mean LINE-1 methylation level (%) ± SD62.8 ± 9.562.5 ± 9.664.3 ± 9.60.5363.9 ± 8.962.3 ± 7.50.79
TP53 expression0.710.0080
 Negative520 (57)422 (55)56 (72)39 (68)3 (60)
 Positive385 (43)343 (44)22 (28)18 (32)2 (40)

NOTE: The % number indicates the proportion of patients with a specific clinical, pathologic or molecular feature among all patients, or patients with specific PIK3CA mutation status.