Table 1.
Serum tryptophan, kynurenine and neopterin, urinary neopterin and biopterin of cancer-free group (Group 1) and colorectal cancer patients (Group 2)
| Group | Group 1 (n = 43) | Group 2 (n = 44) | P value |
| Age (yr)1 | 62.06 ± 2.07 | 60.95 ± 2.11 | 0.708 |
| Tryptophan (μmol/L)1 | 21.95 ± 1.03 | 19.91 ± 1.33 | 0.254 |
| Kynurenine (μmol/L)2 | 1.03 ± 0.19 | 1.20 ± 0.13 | 0.042a |
| Kynurenine/tryptophan1 | 41.31 ± 3.62 | 89.47 ± 14.32 | 0.006a |
| Serum neopterin (nmol/L)2 | 13.28 ± 1.08 | 16.93 ± 2.84 | 0.634 |
| Urinary neopterin (μmol neopterin/mol creatinine | 63.54 ± 5.64 | 80.45 ± 8.09 | 0.090 |
| Urinary biopterin (μmol biopterin/mol creatinine)1 | 67.33 ± 6.22 | 91.41 ± 12.00 | 0.038a |
| Urinary neopterin (μmol neopterin/mol creatinine) + urinary biopterin (μmol biopterin/mol creatinine)1 | 129.83 ± 9.42 | 172.60 ± 17.17 | 0.048a |
a
P < 0.05, Group 2 vs Group 1 considered statistically significant;
1
Independent sample t-test;
2
Mann-Whitney U test. Colorectal cancer patients showed more than two times increase in overall serum kynurenine-tryptophan ratio and a non-significant rise in the activity of pteridine pathway when compared with the cancer-free patients (Group 1).