Table 5. Adjusted odds ratio (AOR) and 95% confidence intervals (CIs) of oral cancer associated with genotypic frequencies of IL-18 -607 A/C and IL-18 -137 G/C among individuals exposure to related environmental risk factors.
| Variable | Controls | Patients | AOR (95% CI) | p value |
|---|---|---|---|---|
| Among areca consumption (n=526) | ||||
| IL-18 -607 | Control (n=93) (%) | Case (n=433) (%) | AOR (95% CI) | p value |
| CC | 21 (22.5%) | 113 (26.1%) | 1.00 | |
| AC | 50 (53.8%) | 190 (43.9%) | 0.78 (0.43-1.42) | p=0.42 |
| AA | 22 (23.7%) | 130 (30.3) | 1.11 (0.56-2.21) | p=0.75 |
| IL-18 -137 | ||||
| GG | 79 (84.9%) | 330 (76.2%) | 1.00 | |
| GC | 12 (12.9%) | 96 (22.2%) | 2.02 (1.01-4.04) | p=0.04 |
| CC | 2 (2.2%) | 7 (1.6%) | 0.81 (0.15-4.26) | p=0.79 |
| IL-18 genes combination | ||||
| Group 1 | 20 (21.5%) | 112 (25.9%) | 1.00 | |
| Group 2 | 60 (64.5%) | 219 (50.6%) | 0.70 (0.39-1.27) | p=0.24 |
| Group 3 | 13 (14.0%) | 102 (23.5%) | 1.54 (0.69-3.41) | p=0.28 |
| Among alcohol consumption (n=550) | ||||
| IL-18 -607 | Control (n=214) (%) | Case (n=336) (%) | AOR (95% CI) | p value |
| CC | 60 (28.0%) | 81 (24.1%) | 1.00 | |
| AC | 104 (48.6%) | 159 (47.3%) | 1.68 (0.93-3.03) | p=0.08 |
| AA | 50 (23.4%) | 96 (28.6%) | 2.38 (1.17-4.86) | p=0.01 |
| IL-18 -137 | ||||
| GG | 199 (93.0%) | 267 (79.5%) | 1.00 | |
| GC | 14 (6.5%) | 63 (18.7%) | 4.04 (1.65-9.87) | p=0.002 |
| CC | 1 (0.5%) | 6 (1.8%) | 8.82 (0.48-161.7) | p=0.14 |
| IL-18 genes combination | ||||
| Group 1 | 60 (28.0%) | 80 (23.8%) | 1.00 | |
| Group 2 | 139 (65.0%) | 188 (56.0%) | 1.54 (0.87-2.72) | p=0.13 |
| Group 3 | 15 (7.0%) | 68 (20.2%) | 5.81 (2.22-15.24) | p=0.0003 |
| Among tobacco consumption (n=702) | ||||
| IL-18 -607 | Control (n=220) (%) | Case (n=482) (%) | AOR (95% CI) | p value |
| CC | 59 (26.8%) | 123 (25.5%) | 1.00 | |
| AC | 107 (48.6%) | 219 (45.4%) | 0.93 (0.57-1.51) | p=0.77 |
| AA | 54 (24.6%) | 140 (29.1%) | 1.20 (0.69-2.09) | p=0.51 |
| IL-18 -137 | ||||
| GG | 185 (84.1%) | 372 (77.2%) | 1.00 | |
| GC | 33 (15.0%) | 102 (21.2%) | 1.66 (1.00-2.84) | p=0.05 |
| CC | 2 (0.9%) | 8 (1.6%) | 1.36 (0.23-7.82) | p=0.72 |
| IL-18 genes combination | ||||
| Group 1 | 57 (25.9%) | 122 (25.3%) | 1.00 | |
| Group 2 | 130 (59.1%) | 251 (52.1%) | 0.84 (0.52-1.36) | p=0.49 |
| Group 3 | 33 (15.0%) | 109 (22.6%) | 1.55 (0.83-2.90) | p=0.16 |
The odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated by logistic regression models.
The adjusted odds ratios (AORs) with their 95% confidence intervals (CIs) were estimated by multiple logistic regression models, after controlling for gender, age, alcohol, tobacco, and areca consumption.
Group 1: individuals with CC of IL-18 -607 and GG of IL-18 -137; Group 2: individuals with at least one of the following, including A/C or A/A of IL-18 -607, or G/C or C/C of IL-18 -137; Group 3: individuals with A/C or A/A of IL-18 -607, and G/C or C/C of IL-18 -137.