MTHFRC677T MTHFRA1298C
 CC  CT TT P for interaction  AA  AC CC P for interaction
  Colorectal cancer (n=70)                
Surgery                
No 0(0%) 5(83.3%) 1(16.7%)    4(100%) 0(0%) 0(0%)  
Palliative  11(36.7%) 16(53.3%) 3(10%)  0.28 17(65.4%) 7(26.9%) 2(7.7%)  0.58
Radical  16(47.1%) 16(47.1%) 2(5.9%)   19(57.6%) 11(33.3%) 3(9.1%)  
Neoadjuvant chemotherapy                
No  21(42%) 26(52%) 3(6%)  0.35* 26(59.1%) 14(31.8%) 4(9.1%)  0.26*
Yes 6(30%) 11(55%) 3(15%)   14(73.7%) 4(21.1%) 1(5.3%)  
Kind of chemotherapy                
Xeloda 5(83.3%) 7(63.6%) 3(100%)   11(78.6%) 2(50%) 1(100%)  
Folfiri 0(0%) 1(9.1%) 0(0%)  0.69 0(0%) 1(25%) 0(0%)  0.35
Folfox 1(16.7%) 3(27.3%) 0(0%)   3(21.4%) 1(25%) 0(0%)  
LV5-FU2 Adjuvant chemotherapy                
No 5(31.3%) 8(50%) 3(18.8%)  0.49* 8(61.5%) 5(38.5%) 0(0%)  
Yes 22(40.7%) 29(53.7%) 3(5.6%)   32(64%) 13(26%) 5(10%)  0.86*
Kind of chemotherapy                
Xeloda 0(0%) 2(6.9%) 0(0%)   0(0%) 2(15.4%) 1(20%)  
Folfiri 3(13.6%) 0(0%) 0(0%)  0.29 3(9.4%) 0(0%) 0(0%)  0.17
Folfox 17(77.3%) 22(75.9%) 3(100%)   25(78.1%) 8(61.5%) 4(80%)  
LV5-FU2 2(9.1%) 5(17.2%) 0(0%)   4(12.5%) 3(23.1%) 0(0%)  
P was calculated between CC versus CT+TT genotype for MTHFRC677T, For MTHFR A1298C P was calculated between AA versus AC+CC genotype
Table 7: interaction of treatment with gastrointestinal cancer.