Background: The aim of this study was to evaluate the risks of the polymorphisms of oxidant stress-related enzymes on patients with oral cavity cancer by genotyping of manganese superoxide dismutase (MnSOD [1183T>C]), myeloperoxidase (MPO [-463G>A]), catalase (CAT [-15A>T]) and glutathione peroxidases 1 (GPx1 [Pro198Leu]).
Methods: A case-control study was conducted on 122 biopsy-proven oral cavity cancer patients with, at least, one of the past habits of cigarette smoking, alcohol drinking or betel-quid chewing, and 122 approximately age- and habit-matched controls.
Results: The independent risks of the polymorphisms for each enzyme on carcinogenicity were non-significant. The 2-order gene-gene interactions of the polymorphisms, assessed by using a logistic regression model, on risk did not show significant changes, neither. However, the epistasis, assessed by multifactor dimensionality reduction (MDR) for three-order (CAT, MnSOD, and MPO) and four-order was significant. Additionally, the fact that the levels of O(2)(-), GSSG and total GSH in the patients were significantly different according to certain genotypes which revealed that the polymorphisms of these enzymes could affect these parameters to some extent.
Conclusions: The results suggested that the genetic-effects of the polymorphisms of these enzymes could slightly modify the risk in oral cavity cancer development individually, but significantly when they functioned together.
2010 Elsevier B.V. All rights reserved.