Table 2.
Effect of the polymorphisms on brain tumor risk.
| Study Type | Number of Participants | Ethnicity | SNP | Histological Stratification | Risk Association | Reference |
|---|---|---|---|---|---|---|
| Case-control Pediatric tumors | 284 cases and 464 controls | Caucasian, East Slav and Russian (grouped together) | C677T | Glial tumors and embryonic brain tumors | No risk associated with brain tumor development | [100] |
| Case-control Pediatric tumors | 73 cases and 205 controls |
Thai | C677T | Brain tumors No stratification |
Statistically non-significant 5.2 times increased risk of glial tumors for the homozygous TT allele | [99] |
| A1298C | Increased risk of embryonic tumors No risk associated with glial and germ cell tumors |
|||||
| Case-control Hospital based | 108 gliomas, 76 meningiomas and 104 controls | Indian | C677T | No WHO malignancy grade stratification | No risk associated with gliomas or meningioma development | [107] |
| A1298C | Increased risk of glioma 38% reduced risk of meningioma for CC and ‘C’ allele containing genotypes |
|||||
| Case-control | 112 glioma cases and 141 controls | Indian | C677T | Astrocytoma, glioblastoma, oligodendroglioma and other types of glioma | No risk associated with any glioma type or overall survival | [112] |
| Case-control Hospital based | 39 HGGs, 35 meningiomas and 98 controls | Turkish | C677T | High-grade gliomas (HGG) and meningiomas | No risk associated with meningioma Non-significant 2.15 times increased risk of HGG for the homozygous TT allele |
[115] |
| Case-control | 93 cases and 93 controls | mixed Brazilian | C677T | Astrocytic tumors subdivided in WHO grade I (17), grade II (19), grade III (14), and grade IV (43) | Potential protective effect for the homozygous TT genotype No risk associated with histological subtypes |
[114] |
| Case-control | 6oo cases and 600 controls | Chinese Han population | C677T | Meningiomas subdivided in WHO grade I (391), grade II (167) and grade III (42) | Reduced risk associated with TT and ‘T’ allele-containing genotypes No risk associated with subtypes |
[119] |
| A1298C | No association with meningioma general risk or subtypes | |||||
| Case-control | 317 cases and 320 controls | Northern Chinese Han population | C677T | Meningioma without WHO grade stratification | Increased risk of meningioma for the TT genotype | [120] |
| A1298C | No risk association | |||||
| Case-control | 631 meningioma, 1005 glioma and 1098 controls | Caucasian | C677T | GBM, oligodendrocytes, other astrocytomas and other gliomas’ subtypes | Increased risk of meningioma, but not glioma | [10] |
| A1298C | Increased risk of meningioma, glioblastoma and oligodendroglioma for the heterozygous genotype | |||||
| Meta-analysis | 1323 cases and 1883 controls from 10 studies | Caucasian, Chinese, Asian | C677T | Meningioma | No risk association | [122] |
| 1855 cases and 3331 controls | A1298C | Increased risk for Caucasian populations in heterozygous (AC) and dominant (CC + AC) models | ||||
| Meta-analysis | 1615 cases and 1909 controls | Asian and Caucasian | C677T | Meningioma without WHO grade stratification | Increased meningioma risk for CT genotype carriers in the total population. No risk associated with Asian populations and increased risk for Caucasian populations with CT and TT genotypes | [121] |
| Meta-analysis | 1786 cases and 2076 controls | Asian, Brazilian and Caucasian | C677T | Glioma without WHO grade stratification | No association was observed for total population or Caucasian populations | [116] |
| Meta-analysis | 3059 cases and 3324 controls | Asian, Brazilian and Caucasian | C677T | Glioma and meningioma | Increased risk for T allele carriers (TC + TT) and 1.38 times increased risk of meningioma for TC carriers Asian populations had an increased brain tumor risk, but no association was observed for Caucasian populations | [117] |
| Meta-analysis | 2236 cases and 2248 controls from five studies | Asian and Caucasian | A1298C | Glioma and meningioma | Increased glioma risk in the total population. In Caucasian populations, increased risk of meningioma and glioma in the heterozygous model (AC) and dominant model (CC + AC) | [118] |
| Case-control | 328 cases and 400 controls | Caucasian | C677T | Glioblastoma | No risk associated with the polymorphism | [111] |
| Retrospective cohort study | 214 patients | Caucasian | C677T | Glioblastoma | Poor overall survival in patients younger than 60 years | [123] |
| A1298C | No association with overall survival |
PNET = primitive neuroectodermal tumor; AT/RT = atypical teratoid rhabdoid tumor; WHO = World Health Organization; HGG = high-grade glioma.