SPECIFICITIES OF ENDOMETRIAL PROLIFERATION/STEM CELL INDEX DISTRIBUTION IN ENDOMETRIOID CARCINOMA OF DIFFERENT GRADE OF MALIGNANCY.

Endometrial neoplasia is the most common malignant tumor of female genital system in developed countries. The incidence of endometrial cancer has increased in the last years and despite advances in diagnosis and treatment, the death rates have steadily been increasing over the past 20 years. Therefore aspects of endometrial cancer development, pathogenesis and effective treatment is especially urgent to this day, as much of the risk for endometrial cancer development is influenced by the environment and lifestyle. Endometrial stem cells take the special place among somatic stem cells of female reproductive system-the detection of them and identification of their location in the complex cellular hierarchy still remains challenging. Further study of endometrial stem cells will clarify their role in gynecologic pathologies associated with hyper-proliferative states of endometrium. The aim of our study was to explore the specificities of endometrial proliferative/stem cell index distribution under endometrioid carcinoma of different grade of malignancy. The study represents a retrospective research. The coded and depersonalized material data from Acad. N. Kipshidze Central University Clinic was used in the study. 3 study groups - 1st study group "Endometrioid Carcinoma Grade 1" (14 cases), 2nd study group "Endometrioid Carcinoma Grade 2" (23 cases) and 3rd study group "Endometrioid Carcinoma Grade 3" were selected from routine histopathology tissue specimens of uterus. Hematoxilyn-eosin technology and immunohistochemistry with proliferation marker ki67 and stem cell marker CD146 was performed. The proliferative/stem cell index was calculated by the ratio of Ki67-positive cell percentage value divided by CD146-positive cell percentage value. The study showed that in the 1st study group labeled as "Endometrioid Carcinoma Grade 1", the proliferative/stem cell index ranges between 21.7 and 25.5. Its mean average value in the age distribution subgroups accounts for: 1.1) reproductive age - 22.4; 1.2) menopause - 23.5; 1.3) post-menopause - 24.8. Proliferative/stem cell index reaches its maximum in the samples retrieved from post-menopause age, and decreases significantly in reproductive age individuals. In the 2nd study group labeled as "Endometrioid Carcinoma Grade 2", the proliferative/stem cell index increases and ranges within the interval 23.2-27.8. Its mean average value in the age distribution subgroups accounts for: 2.1) reproductive age -23.7; 2.2) menopause - 24.2; 2.3) post-menopause - 25.8. In the 3rd study group labeled as "Endometrioid Carcinoma Grade 3", the proliferative/stem cell index markedly increases and ranges within the interval 25.8-29.4. Its mean average value in the age distribution subgroups accounts for: 3.1) reproductive age - 28.4; 3.2) menopause - 28.5; 3.3) post-menopause - 28.5. It was found that average value of proliferative/stem cell index in the 1st and 2nd study groups (EC Grade 1/2) keeps the same tendencies of increase in age subgroups as well as at endometrial hyperplasia conditions - in particular in both study groups increase in value of the proliferative/stem cell index in age subgroups makes about 1% (1st study group-0,97%, 2nd study group-0,96%). What about 3rd study group (EC Grade 3) average value of proliferative/stem cell index in age subgroups is almost the same. It was found that average value of proliferative/stem cell index in endometrioid carcinoma most markedly differs from the norm in post-menopause period. The study showed that average value of proliferative/stem cell index in endometrioid carcinoma cases (EC Grade 1/2) tends to increase with age like endometrial hyperplasia conditions, in contrast with the norm, where it is observed to progressively decrease with aging. The attention should be given to the fact that the mean average value of proliferative/stem cell index in endometrioid carcinoma Grade 3 is almost constant.