BACKGROUND
Salivary gland carcinomas (SGCs) are a rare malignancy with unknown etiology. We aimed to identify genetic variants modifying risk of SGC and its major subtypes, adenoid cystic carcinoma (ACCA) and mucoepidermoid carcinoma (MECA).
METHODS
We conducted a genome-wide association study in 309 well-defined SGC cases and 535 cancer-free controls. We performed a SNP-level discovery study in non-Hispanic whites followed by a replication study in Hispanics. A logistic regression was applied to calculate odds ratios (ORs) and 95% confidence intervals (95%CIs). A meta-analysis was conducted of the results.
RESULTS
Genome-wide significant association with SGC in non-Hispanic whites was detected at coding SNPs in CHRNA2 (OR=8.55, 95%CI: 4.53–16.13, P = 3.6 × 10−11), OR4F15 (OR=5.26, 95%CI: 3.13–8.83, P = 3.5 × 10−10), ZNF343 (OR=3.28, 95%CI: 2.12–5.07, P = 9.1 × 10−8), and PARP4 (OR=2.00, 95%CI: 1.54–2.59, P = 1.7 × 10−7). Meta-analysis of the non-Hispanic white and Hispanic cohorts identified another genome-wide significant SNP in ELL2 (meta-OR=1.86, 95%CI: 1.48–2.34, P = 1.3 × 10−7). Risk alleles largely enriched in MECA, where the SNPs in CHRNA2, OR4F15, and ZNF343 had ORs of 15.71 (95%CI: 6.59–37.47, P = 5.2 × 10−10), 15.60 (95%CI: 6.50–37.41, P = 7.5 × 10−10), and 6.49 (95%CI: 3.36–12.52, P = 2.5 × 10−8), respectively. None of these SNPs retained significant association with ACCA.
CONCLUSIONS
These findings, for the first time, identify a panel of SNPs associated with SGC risk. Confirmation of these findings along with functional analysis of identified SNPs are needed.