KALAEVA A. Features of progress and course of endometrial cancer at methylation of GST and ESR genes.

Based on the results of examining 159 patients with endometrial cancer (EC) and 94 patients with endometrial hyperplasia it was established that the frequency of gene ESR epigenetic disorders significantly increases along with the disease aggravation in the endometrium, whereas methylation ESR genes significantly reduces the effectiveness of hormone therapy in patients with endometrial hyperplasia and increases the risk of pathology aggravating in the endometrium (recurrence of hyperplasia, progress of atypical hyperplasia and EC). The pathogenic role of the ESR gene in endometrial precancer and cancer progress has been demonstrated. It was established that the frequency of GST gene methylation was higher in patients with non-endometrioid EC carcinomas (51,4%) as compared with endometrioid carcinomas (31,1%), and in patients with low-differentiated (LD) carcinomas - 41,2%. ESR gene epigenetic disorders were more common in patients with endometrial forms of cancer (58,2%) as compared with non-endometrial forms (32,4%) and in patients with highly- and moderately differentiated adenocarcinomas: 68,3% and 65,2% respectively. Evaluation of the treatment effectiveness showed that methylation of the ESR gene does not increase incidence of relapses (6,0% versus 7,1% in the control group). Methylation of the GST gene is accompanied by more frequent relapses of EC (10,5%). We established that GST gene methylation does not significantly affect the effectiveness of chemotherapy (CT) of patients with EC, whereas gene ESR methylation increases efficiency of chemotherapy in patients with non-endometrioid forms of EC.