Hydrogen peroxide: a potent cytotoxic agent effective in causing cellular damage and used in the possible treatment for certain tumours.

H2O2, a highly reactive agent, can react under certain conditions with a variety of cellular components. These reactions include the lipid peroxidation of membrane and hydroxylation of proteins and DNA. The reactions can take place in the presence of oxygen and are fairly rapid, the H2O2 being converted to water and oxygen. Experiments were carried out in vitro to assess the ability of this agent to destroy cancer cells without generating dangerous by-products. The direct administration of aqueous H2O2 into solid tumours has the potential to cause tumour cell death. The efficacy of the use of H2O2 for treating 'solid' cancers will necessitate its delivery to the tumour site, for example by direct special multiple injection of H2O2 into a detectable tumour mass. We anticipate that, if suggested mode of delivery can be obtained, H2O2 can act as an anti-cancer drug with two distinct advantages over conventional chemotherapeutic agents: to produce minimal short- and long-term side-effects and is relatively cheap and cost effective.