Table 2 Basic characteristics of included studies for this meta-analysis
Study author | Study year | Country | Ethnicity | Cancer type | Design | Source of controls | Genotyping method | Matching criteria | Cases | Controls | HWE | Quality score | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
AA | AG | GG | AA | AG | GG | |||||||||||
IL-17A rs2275913 | ||||||||||||||||
 Omrane et al. | 2014 | Tunisia | Caucasian | Colorectal cancer | Retrospective study | HB | PCR-RFLP | Not mentioned | 3 (2.9%) | 51 (50.0%) | 48 (47.1%) | 6 (4.3%) | 38 (27.4%) | 95 (68.3%) | 0.387 | 10 |
 Nemati et al. | 2015 | Iran | Caucasian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Age, sex, ethnic, geographic origin | 82 (27.0%) | 100 (32.9%) | 122 (40.1%) | 50 (17.4%) | 110 (38.2%) | 128 (44.4%) | 0.002 | 14 |
 Samiei et al. | 2018 | Malaysia | Asian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Not mentioned | 27 (38.6%) | 33 (47.1%) | 10 (14.3%) | 12 (15.0%) | 41 (51.2%) | 27 (33.8%) | 0.577 | 11 |
 Al Obeed et al. | 2018 | Saudi Arabia | Caucasian | Colorectal cancer | Retrospective study | PB | qRT-PCR | Gender, age | 17 (14.5%) | 40 (34.2%) | 60 (51.3%) | 7 (7.0%) | 23 (23.0%) | 70 (70.0%) | 0.018 | 12 |
 Bedoui et al. | 2018 | Tunisia | Caucasian | Colorectal cancer | Retrospective study | PB | TaqMan | Ethnic origin | 14 (4.8%) | 79 (27.1%) | 199 (68.1%) | 9 (3.5%) | 58 (22.2%) | 194 (74.3%) | 0.084 | 14 |
 Feng et al. | 2019 | China | Asian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Sex, age | 37 (10.5%) | 154 (43.9%) | 16 0 (45.6%) | 31 (7.2%) | 169 (39.2%) | 231 (53.6%) | 0.991 | 16 |
 Moundir et al. | 2019 | Morocco | Caucasian | Colorectal cancer | Retrospective study | HB | TaqMan | Not mentioned | 41 (58.6%) | 22 (31.4%) | 7 (10.0%) | 27 (38.6%) | 18 (25.7%) | 25 (35.7%) | < 0.001 | 6 |
 Zhang et al. | 2020 | China | Asian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Gender, age | 41 (19.7%) | 110 (52.9%) | 57 (27.4%) | 45 (14.4%) | 149 (47.8%) | 118 (37.8%) | 0.854 | 16 |
IL-17F rs763780 | ||||||||||||||||
 Omrane et al. | 2014 | Tunisia | Caucasian | Colorectal cancer | Retrospective study | HB | PCR-RFLP | Not mentioned | 1 (0.7%) | 38 (27.8%) | 98 (71.5%) | 1 (1.0%) | 27 (27.0%) | 72 (72.0%) | 0.374 | 10 |
 Nemati et al. | 2015 | Iran | Caucasian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Age, sex, ethnic, geographic origin | 337 (93.6%) | 0 (0.0%) | 23 (6.4%) | 391 (97.3%) | 0 (0.0%) | 11 (2.7%) | < 0.001 | 14 |
 Li et al. | 2016 | China | Asian | Colorectal cancer | Retrospective study | PB | PCR-HRM | Sex, age | 0 (0.0%) | 13 (26.0%) | 37 (74.0%) | 0 (0.0%) | 10 (20.0%) | 40 (80.0%) | 0.432 | 14 |
 Samiei et al. | 2018 | Malaysia | Asian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Not mentioned | 5 (7.2%) | 25 (35.7%) | 40 (57.1%) | 1 (1.2%) | 23 (28.8%) | 56 (70.0%) | 0.419 | 11 |
 Al Obeed et al. | 2018 | Saudi Arabia | Caucasian | Colorectal cancer | Retrospective study | PB | qRT-PCR | Gender, age | 110 (94.0%) | 7 (6.0%) | 0 (0.0%) | 94 (94.0%) | 6 (6.0%) | 0 (0.0%) | 0.757 | 15 |
 Feng et al. | 2019 | China | Asian | Colorectal cancer | Retrospective study | PB | PCR-RFLP | Sex, age | 10 (2.8%) | 100 (28.5%) | 241 (68.7%) | 16 (3.7%) | 132 (30.6%) | 284 (65.7%) | 0.892 | 16 |