The significance of reduced glutathione and glutathione S-transferase during chemoradiotherapy of locally advanced cervical cancer

Background and objective: To determine changes in reduced glutathione (GSH) and glutathione S-transferase (GST) during neoadjuvant chemotherapy followed by concurrent chemoradiation for patients with stage IIB–IIIB cervical cancer, and to evaluate their significance to the efficacy of the treatment.
Materials and methods: According to the prospective phase II study protocol, 36 patients with stage IIB–IIIB cervical cancer were enrolled. A short course of intensive weekly neoadjuvant cisplatin and gemcitabine chemotherapy followed by concurrent weekly cisplatin and gemcitabine-based chemoradiation was administered. Blood samples for GSH, GST analysis were collected and analyzed before the start of the treatment, after neoadjuvant chemotherapy, and after the end of the chemoradiation.
Results: A statistically significant increase in the concentration of GSH after neoadjuvant chemotherapy was identified. After chemoradiation, values of this rate significantly decreased in contrast with GSH concentration after neoadjuvant chemotherapy in cases of stage IIB, regional metastases negative patients group, patients with a positive response to treatment, and patients who had no progression of the disease during the first 2 years after treatment. Statistically significant changes in GST during the treatment were not identified; the GST concentration after chemoradiation showed a statistically significant difference in GST con- centrations in terms of the progression of the disease and disease without progression.
Conclusions: The results suggest that changes in the concentration of GSH during the treatment of locally advanced cervical cancer might be important for the prediction of the efficacy of the treatment. Statistically significant changes in GST concentration levels during the treatment were not observed.