An imbalance in oxidant/antioxidant dynamics: correlation with therapeutic response in patients with carcinoma of posterior one third of the tongue.

The objective was to study the alterations in circulating pro-/antioxidants in patients with cancer of the posterior one third of the tongue, before and after concomitant chemoradiation, and to assess variation in their levels to therapeutic response. Sixty patients with newly diagnosed squamous cell carcinoma of the posterior one third of the tongue and 60 healthy controls were enrolled. Blood samples were collected before and after chemoradiation and after 3 months of follow-up. Pro-/antioxidant levels were estimated using standard methods. Response to therapy was assessed during and after therapy and after 3 months of followup. Pretreatment levels of lipid peroxide were significantly elevated while antioxidant levels were lowered in cancer patients compared to controls. After chemotherapy, lipid peroxidation showed a significant decline, while antioxidants showed a significant rise in complete responders, compared with partial/nonresponders, and remained highly significant after therapy and during follow-up. Pretreatment levels of antioxidant-oxidant parameters and the extent of their change during treatment can predict the therapeutic response to concomitant chemoradiation in carcinoma tongue.