Table 2.
SHMT1 genotype and allele frequencies of lung cancer cases and cancer-free controls and their association with risk of lung cancer
| Genotype | Number of subjects (%) |
P value b | Crude OR (95% CI) | Adjusted OR (95% CI) c | |
|---|---|---|---|---|---|
| Patients | Controls a | ||||
| Total | 1032 (100.0) | 1145 (100.0) | |||
| Promoter region | |||||
| rs643333 | |||||
| AA | 104 (10.1) | 117 (10.2) | 0.836 | 1.00 | 1.00 |
| CA | 476 (46.1) | 541 (47.3) | 0.99 (0.74–1.33) | 0.97 (0.71–1.32) | |
| CC | 452 (43.8) | 487 (42.5) | 1.04 (0.78–1.40) | 0.98 (0.72–1.34) | |
| C allele | 0.669 | 0.662 | 0.624 | ||
| CA+CC | 928 (89.9) | 1028 (89.8) | 0.914 | 1.02 (0.77–1.34) | 0.97 (0.72–1.31) |
| rs638416 | |||||
| CC | 127 (12.3) | 160 (14.0) | 0.381 | 1.00 | 1.00 |
| CG | 505 (48.9) | 532 (46.4) | 1.20 (0.92–1.56) | 1.35 (1.02–1.79) | |
| GG | 400 (38.8) | 453 (39.6) | 1.11 (0.85–1.46) | 1.24 (0.93–1.65) | |
| G allele | 0.632 | 0.628 | 0.768 | ||
| CG+GG | 905 (87.7) | 985 (86.0) | 0.251 | 1.16 (0.90–1.49) | 1.30 (1.00–1.70) |
| Exon 12 (L435F) | |||||
| rs1979277 | |||||
| CC (LL) | 459 (44.5) | 495 (43.2) | 0.535 | 1.00 | 1.00 |
| CT (LF) | 431 (41.7) | 504 (44.0) | 0.92 (0.77–1.11) | 0.95 (0.78–1.15) | |
| TT (FF) | 142 (13.8) | 146 (12.8) | 1.05 (0.81–1.37) | 1.10 (0.83–1.46) | |
| T allele | 0.654 | 0.652 | 0.935 | ||
| CC+CT | 890 (86.2) | 999 (87.3) | 0.488 | 1.00 | 1.00 |
| TT | 142 (13.8) | 146 (13.8) | 1.09 (0.85–1.40) | 1.13 (0.87–1.47) | |
| 3′-UTR | |||||
| rs3783 | |||||
| CC | 457 (44.2) | 500 (43.7) | 0.805 | 1.00 | 1.00 |
| CG | 464 (45.0) | 529 (46.2) | 0.96 (0.80–1.15) | 0.98 (0.81–1.18) | |
| GG | 111 (10.8) | 116 (10.1) | 1.05 (0.78–1.40) | 1.10 (0.81–1.50) | |
| G allele | 0.332 | 0.332 | 0.997 | ||
| CC+CG | 921 (89.2) | 1029 (89.9) | 0.634 | 1.00 | 1.00 |
| GG | 111 (10.8) | 116 (10.1) | 1.07 (0.81–1.41) | 1.11 (0.83–1.49) | |
| rs1979276 | |||||
| TT | 110 (10.7) | 131 (11.4) | 0.461 | 1.00 | 1.00 |
| CT | 457 (44.3) | 528 (46.1) | 1.03 (0.78–1.37) | 1.04 (0.77–1.41) | |
| CC | 465 (45.0) | 486 (42.5) | 1.14 (0.86–1.51) | 1.12 (0.83–1.51) | |
| C allele | 0.672 | 0.655 | 0.237 | ||
| TT+CT | 567 (54.9) | 659 (57.5) | 0.220 | 1.00 | 1.00 |
| CC | 465 (45.0) | 486 (42.5) | 1.11 (0.94–1.32) | 1.08 (0.90–1.30) | |
The observed genotype frequency distributions in the controls were in agreement with Hardy-Weinberg equilibrium (p2 + 2pq + q2 = 1) (χ2 = 3.484, P = 0.062 for rs643333; χ2 = 0.036, P = 0.849 for rs638416; χ2 = 0.995, P = 0.318 for rs1979277; χ2 = 1.936, P = 0.164 for rs3783; and χ2 = 0.474, P = 0.491 for rs1979276).
Two-sided χ2 test for the difference in the genotype or allele distributions between the cases and the controls.
Due to missing data, 932 cases and 1073 controls were analyzed with adjustment for age, sex, smoking status, square root of pack-years smoked, alcohol drinking status, and dietary intake of total folate, vitamin B6, vitamin B12, and methionine in logistic regression models.