Table 3.
The characteristics of the included studies.
| Study | Country | Ethnicity | Male, N (%) | Age (mean ± SD or mean [25th, 75th percentile]) | Cases | Controls | Genotype (CC/TC/TT) | Genotyping method | Adjustment | HWE | NOS score* | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Case | Control | |||||||||||
| Thabet (2016) (8) | Multi-country | Caucasian | Case: NA; Control: 1101 (64.5) | Case: NA; Control: 44.9 (38–52) | 75 | 1706 | 24/35/16 | 16/531/822 | TaqMan | Age, gender, BMI and Child-Pugh score | 0.288 | 9 |
| Stickel (2018) (9) | Switzerland | Mixed | Case: 679 (90); Control: 817 (70) | Case: 61 ± 10; Control: 55 ± 10 | 751 | 1165 | 203/363/185 | 185/314/583 | TaqMan | Age, gender, BMI, and type II diabetes mellitus | 0.934 | 7 |
| Raksayot (2019) (10) | Thailand | NA | Case: 424 (0.8); Control: 77 (73.3) | HBV-HCC: 62.1 ± 7.8, HCV-HCC: 62.2 ± 7.5, NBNC-HCC: 63.3 ± 9.3; Control: 50.7 ± 4.6 | 530 | 105 | 279/213/38 | 38/66/34 | TaqMan | No | 0.818 | 6 |
| This study | China | Chinese | Case: 550 (70.6); Control: 966 (68.4) | Case: 53.2 ± 12.5; Control: 52.3 ± 12.2 | 779 | 1412 | 426/295/58 | 58/800/528 | Massary | Age, sex, smoking and drinking status | 0.403 | 7 |
*NOS score ≥ 7 is often considered as high-quality.