Does fall in serum glutathione predict the long-term outcome to concurrent chemoradiation for cervical cancer patients?

Background: Wide variations are seen in clinical practice with respect to response to concurrent chemo radiation among cervical cancer patients. Fall in serum glutathione (GSH) level directly correlates with early response to treatment. Whether this early response translates to a better long term outcome is the subject of this prospective study. Materials and Methods: Thirty eight women with cervical cancer were treated with concurrent chemo radiation followed by brachytherapy. Serum GSH was measured before and after two fractions of radiation and first chemotherapy. Patients were followed for a median follow up of four years. Fall in GSH was correlated with response at six weeks and disease status at four years. Results: Median fall in serum GSH was 171.16 mu g per ml. Fall in GSH was 170.42,103.54 and 37.25 mu g per ml (Pvalue of < 0.0001, 0.05 and 0.18) in patients showing complete response, partial response and no response respectively. Among 26 patients who had no disease at six weeks, 22 women remained disease free at four years (P < 0.0001), two recurred (P < 0.05) and two died of other causes respectively. Non bulky tumours and patients more than 50 years of age showed a fall of 190.69, 265.17 mu g per ml respectively. Conclusion: Greater fall in serum GSH predicts better early response as well as long term disease control.