MTHFR C677T       MTHFR A1298C     P *for interaction
CC CT TT  P* for interaction AA AC CC
Colorectal cancer (n=74)                
Stage                
I 0 2(50) 2(50)   0.43 2(100) 0 0   0.53
II 3(30) 7(70) 0 5(45.5) 4(36.4) 2(18.2)
III 14(41.2  18(52.9) 2(5.9) 20(62.5) 9(28.1) 3(9.4)
IV 8(53.3) 6(40) 1(6.7) 8(72.7) 3(27.3) 0
Lymph node status            
<4 nodes 10(40) 14(56) 1(4) 0.42 16(69.6) 4(17.4) 3(13) 0.45
≥4 nodes 6(54.5) 4(36.4) 1(9.1) 5(55.6) 4(44.4) 0
Differentiation                
Moderately differentiated 12(48) 12(48) 1(4) 0.23** 11(55) 7(35) 2(10) 0.34
Well differentiated 14(33.3)  25(59.5) 3(7.1) 27(67.5) 10(25) 3(7.5)
Histological type ADK    7(30.4)    12(52.2)   4(17.4)   0.24   12(60)   6(30)   2(10)   0.60
ADK Luberkhunien 13(46.4) 14(50) 1(3.6)   12(52.2) 9(39.1) 2(8.7)  
ADK infiltrant 3(50) 3(50) 0   6(90) 1(10) 0  
Other type of ADK 4(16.2) 8(80) 1(3.8)  0.42 10(65) 3(31.2) 1(3.8) 0.46
P*: For MTHFR C677T, CC as reference group and CT grouped with TT; for MTHFR A1298C AA as reference grouped with AC+CC P**: For differentiation was calculated between moderately and well differentiated
Table 6: Interaction between MTHFR polymorphisms and prognostic factor with colorectal and gastric cancer.