Table 2.
Vitamin D studies and polymorphism in breast cancer.
| Study (year) | Study type | Polymorphism | Population | Case/control | OR (95% CI) | Results |
|---|---|---|---|---|---|---|
| Iqbal and Khan (2017)6 | Systemic review and meta-analysis | Cdx2, Fok1, Bsm1, Apa1, Bgl1, Taq1, and poly(A) | Asian, white, African American, Hispanic, European, Japanese, Hawaiian, Polish, German, French Canadian, Swedish, Turkish | 34 studies (26, 372/32, 883) | Bsm1 bb versus BB; SOR = 1.18, 95% CI = 1.054-1.322 Apa1 aa versus AA; SOR = 1.18, 95% CI = 0.87-1.59 Poly(A) LL versus SS; SOR = 1.41, 95% CI = 1.06-1.88 Fok1 ff + Ff versus FF; SOR = 1.25, 95% CI = 0.896-1.759 Apa1 aa + Aa versus AA; SOR = 1.13, 95% CI = 0.95-1.35 Poly(A) LL + LS versus SS; SOR = 1.19, 95% CI = 1.00-1.43 Poly(A) L versus S; SOR = 1.18, 95% CI = 1.03-1.35) |
VDR gene polymorphisms: Bsm1, Apa1, poly(A), Fok1, Apa1 were associated with the breast cancer, whereas Cdx2, Bgl1, and Taq1 do not show any association with breast cancer |
| Laczmanski et al (2017)44 | A meta-analysis | FokI | 125 951 persons from 135 populations | Fok1 associated with increased breast cancer risk (OR = 0.96, 95% CI = 0.93-0.99) | F variant reduces the risk of cancer by 4%, irrespective of the location of the cancer | |
| Lu et al (2016)45 | Meta-analysis | Fok1, Bsm1, Taq1, Apa1 | Asian, white, African American, Hispanic Hawaiian | 8 studies | There were no association between Fok1 gene allele contrast f versus F (OR = 0.859; 95% CI = 0.685-1.079) | The estimated VDR polymorphism showed no significant association between Fok1, Bsm1, Taq1, Apa1 polymorphism, and breast cancer risk |
| El-Shorbagy (2017)46 | Case-control | Taq1, Apa1, Bsm1 | Egyptian | 100/50 | TC in Taq1 and TG in Apa1 showed an increased risk of breast cancer (OR = 3.71, 95% CI = 1.04-13.28 and OR = 7.05, 95% CI = 2.02-24, respectively) | ApaI and TaqI confer high breast cancer susceptibility, in Egyptians women |
| Atoum et al (2017)47 | Case-control | Taq1 | Jordanians | 122/100 | TaqI TT, Tt, and tt genotype frequencies were 41%, 46%, and 13% for breast cancer compared with 42%, 50%, and 8% for control | Statistical difference was found between different VDR TaqI genotypes and circulating levels of 25(OH)D among Jordanian women with breast cancer |
| Rashid et al (2015)48 | Hospital-based case-control study | Bsma1 and Fok1 | Pakistan | 463/1012 | b allele of the BsmI was associated with an increased breast cancer risk (OR = 1.28, 95% CI = 1.09-1.49) | BsmI but not Fok1 polymorphism in the VDR gene was associated with an increased breast cancer risk in Pakistani women negative for BRCA1/2 germline mutations |
| Colagar et al (2015)25 | Case-control | Iranian | 134/127 | L allele frequency was significantly higher in patients with cancer than in controls (OR = 1.73, CI = 1.16-2.57) | VDR gene polymorphism in the poly(A) microsatellite is associated with 25(OH)D levels and that can affect the breast cancer risk | |
| Shahabi et al (2017)49 | Cohort | FokI, BsmI | Iranian | 203/214 | An association between the bb and Bb genotypes of the BsmI and the increased risk of breast cancer (OR = 1.74, CI = 1.06-2.87 and OR = 2.08, CI = 1.31-3.29, respectively) | BsmI but not Fok1 was associated with the risk of breast cancer in Iranian women |
| Shaikh et al (2016)50 | Mini review | Fok1, Bsm1, Taq1, Apa1, poly(A) | Asian, white, African American, Hispanic, non-Hispanic, German, Turkish, Spanish, Indian, Australian, Taiwanese, Chinese, Latinas, Mixed, Finnish | 23 studies | — | No conclusive statements could be presented about the significance of the VDR genotype Fok1, Bsm1, Taq1, Apa1, and poly(A) on breast cancer development |
Abbreviations: CI, confidence interval; OR, odds ratio; VDR, vitamin D receptor.