Abstract
Insulin-like growth factors (IGF) play important roles in carcinogenesis. The associations of circulating IGF-1 and insulin-like growth factor-binding protein-3 (IGFBP-3) with the risks of bladder cancer remain unclear. In this large case control study of 2011 bladder cancer cases and 2369 heathy controls, we assessed the associations of circulating IGF-1 and IGFBP-3 with bladder cancer risks using a Mendelian randomization approach, which uses genetic variants as instruments to study causal relationship between risk factors and diseases. We first constructed a weighted genetic risk score (GRS) predictive of circulating IGF-1 and IGFBP-3 using 413 genome-wide association study-identified single nucleotide polymorphisms (SNPs) associated with IGF-1 and four SNPs with IGFBP-3, respectively. We found that higher GRS for IGF-1 was associated with a significantly reduced bladder cancer risk (odds ratio [OR] = 0.66 per SD increase, 95% confidence interval [CI], 0.54–0.82, p < 0.001). We then used a summary statistics-based MR method, inverse-variance weighting (IVW), and found a similar risk estimate (OR = 0.67 per SD increase, 95% CI = 0.54–0.83, p < 0.001). When we categorized individuals into high and low IGF-1 groups using the median GRS value in the controls, the high GRS group had a 21% reduced bladder cancer risk (OR = 0.79, 95% CI = 0.70–0.89) compared to the low GRS group. Genetically predicted circulating IGFBP-3 was not associated with bladder cancer risk. In conclusion, our data demonstrated for the first time a strong inverse relationship between circulating IGF-1 level and bladder cancer risk.
Original language | English (US) |
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Pages (from-to) | 726-733 |
Number of pages | 8 |
Journal | Molecular Carcinogenesis |
Volume | 60 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2021 |
Keywords
- IGF-1
- Mendelian randomization
- SNP
- bladder cancer
- genetic risk score
ASJC Scopus subject areas
- Molecular Biology
- Cancer Research