Glutathione Transferases Omega-1 and -2 Polymorphisms in Cancer: Drivers or Silent Bystanders?

The omega class of glutathione transferases (GSTOs) includes two enzymes that catalyze atypical reactions, influencing key cellular processes such as cell survival, proliferation, drug resistance, and inflammation. In recent years, numerous studies have focused on GSTOs’ role and on the significance of their polymorphisms in cancer risk and progression; though findings have been somewhat inconsistent. This systematic review aims to critically evaluate the current literature to determine whether GSTOs’ polymorphisms may represent significant contributors to tumor progression, by analyzing their association with severity, mortality, and disease progression across different cancer types. Although for some types of neoplasms the studies reporting positive correlations are the majority, the role of GSTOs’ polymorphisms in cancer remains inconclusive due to conflicting findings, limited data on rare variants, and multiple confounding factors; further research is needed to clarify their tissue-specific and context-dependent effects.