Oleshko K. Endometrial cancer progression peculiarities in terms of microsatellite instability

342 patients with endometrial cancer (EC) were examined with microsatellite instability (MSI) occurrence detected in tumour tissue of 115 patients, in blood serum of 37 patients and in colon tissue (mucosal lining) of 21 patients. It was established that expression of immunohistochemical tumour markers correlated with EC MSI phenotype, disease stage and neoplasm differentiation degree. The main immunohistochemical factors complementary to EC biological properties imply Ki 67 expression of estrogen receptors (ER) and progesterone receptors (PR). Data on 3-year progression-free survival (PFS) of patients aged over 40 demonstrate reliable dependence on MSI phenotype of the tumour: 86.8 % with MSI+ phenotype and 100 % with MSI- phenotype, p<0.01. Regarding EC stage I the 3-year progression-free survival (PFS) rate was significantly higher in patients without microsatellite disorders (97.5 % against 84.8 %, p <0.01). A similar relationship, however, with a much lesser reliability degree has been traced in patients with both EC stage II and III. The obtained data allow personalizing treatment of patients with EC (chemotherapy, hormone therapy) depending on MSI tumour phenotype along with Ki 67, ER and PR consideration, which would improve the treatment efficiency and reduce the number of EC relapses. At that, the obtained data can also be used for early diagnosis of colon cancer.