Oxidative stress and antioxidants in carcinogenesis and integrative therapy of cancer.

Oxidative stress is often considered as a causative factor in carcinogenesis. In addition, current knowledge recognizes oxidative stress as a mechanism by which various cancer therapies act against cancer. To ameliorate the side effects of cancer therapy, many of the patients suffering from cancer are subject to adjuvant therapy, which often implies antioxidant supplementation. Yet, the benefits of such adjuvant treatments are still uncertain owing to the lack of appropriate integrative and personalized medical approach. In particular, reactive oxygen species formed during oxidative stress and products of lipid peroxidation are not only cytotoxic, but can modulate signal transduction in cells, which also behave similar to individuals under stress. Accordingly, pro-oxidants and antioxidants might be considered as modifiers of specific cellular redox signaling. Therefore, there is a need to evaluate the potential benefits of antioxidant supplements in healthy persons, and in particular in cancer patients during therapy. Our review will present a summary of the existing knowledge regarding the effects of various antioxidants in cancer therapies, focusing on cellular adaptation to oxidative stress interacting with redox signaling transduction pathways thereby influencing cell growth.