Background: Antitumor T lymphocytes play an essential part in immune surveillance of cancer cells. Cytotoxic T lymphocyte-associated Protein 4 (CTLA-4) is a negative regulator of T cell activation and proliferation and therefore influences immune surveillance of carcinogenesis of pancreas. Thus, this study examined the association between functional CTLA-4 49G-to-A (49G>A) single-nucleotide polymorphism and pancreatic cancer risk.
Methods: Genotypes were determined in 368 patients with pancreatic cancer and 926 controls, and odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression.
Results: A significant increased risk of pancreatic cancer was found to be associated with the CTLA-4 49G>A single-nucleotide polymorphism. Compared with noncarriers, the OR of developing pancreatic cancer for CTLA-4 49 GA or AA carriers was 1.75 (95% CI = 1.34-2.30, P = 4.83 × 10(-5) ) or 2.54 (95% CI = 1.67-3.87, P = 1.36 × 10(-5) ), respectively. In stratified analyses, the association was more pronounced in GA and AA carriers aged ≤60 years (OR = 3.10, 95% CI = 2.15-4.47, P(interaction) = .002), smokers with GA and AA genotypes (OR = 3.92, 95% CI = 2.39-6.43, P(interaction) = .037), and drinkers with GA and AA genotypes (OR = 4.55, 95% CI = 2.65-7.82, P(interaction) = .042), compared with GG carriers. Moreover, a supermultiplicative interaction between the CTLA-4 49AA genotype and smoking plus drinking was also evident in intensifying risk of pancreatic cancer (P(interaction) = 5.64 × 10(-12) ).
Conclusions: These results suggest that CTLA-4 49G>A polymorphism is involved in susceptibility to developing pancreatic cancer, alone and in a gene-environment interaction manner.
Copyright © 2012 American Cancer Society.