Oxidant/anti-oxidant dynamics in patients with advanced cervical cancer: correlation with treatment response

Cervical cancer is the most common cancer in Indian women. Oxidative stress is potentially harmful to cells and ROS are involved in multistage carcinogenesis, in initiation and promotion. The aim was to study the alterations in the circulating pro-/anti-oxidants in advanced cervical cancer patients, before and after neoadjuvant chemoradiation and to assess the relevance of the variation in the levels to therapeutic response. 90 patients with advanced cancer cervix (FIGO IIIa-IVa) and 90 healthy controls were enrolled. Blood samples were collected: before and after chemotherapy, after radiation and after 1 year on follow-up. Pro-/anti-oxidant levels were estimated using standard methods. Response to therapy was assessed during and after therapy and after 1 year of follow-up. The pre-treatment levels of plasma lipid peroxide were significantly elevated; while antioxidant levels were lowered in cancer patients; when compared to controls. After chemotherapy, lipid peroxidation showed a significant decline in complete responders, as compared with partial/non-responders and remained highly significant after therapy and during follow-up. Anti-oxidant enzymes showed a mild increase (P < 0.05), after chemotherapy in complete responders, as compared with partial/non-responders and remained highly significant after therapy and on follow-up. This important finding suggests that pre-treatment levels of antioxidant-oxidant parameters and the extent of their change during treatment can predict the therapeutic response to neoadjuvant chemoradiation in advanced cancer cervix. Oxidant-antioxidant profile merits investigation as markers of response, survival, and recurrence in larger prospective studies, which might throw light on their possible use as predictors of chemoradiosensitivity of cervical tumors.