Diagnostic value of tumor suppressor P53gene and proliferative Ki67 marker expression in uterine leiomyomas / Монголын Анагаах Ухаан

ABSTRACT

Aim was to investigate expression of tumor suppressor P53 gene, proliferating Ki-67 protein inordinary and proliferating uterine leiomyomato establish possible usefulness of these two parametersin distinguishing between ordinary leiomyoma and proliferating leiomyoma. Retrospective study of49uterine leiomyoma (25 ordinary leiomyoma, 24 proliferating leiomyoma) technically acceptable foranalysis from years 2010–2013 department of Obstetrics and Gynecology and department of Pathology,Mongolian National University of Medical Science, Ulaanbaatar, Mongolia.MethodAll tissue specimens were obtained from surgically removed tumors. Tissue was fixed in formalinand cut to thickness of 5 mm from paraffin-embedded blocks. All haematoxylineosin slides and allimunohistochemical slides for each case were reviewed by two experienced pathologist.ImmunohistochemistryParaffin-embedded tumor sections were deparaffinized and stained in automated platformDakoCytomationusing monoclonal mouse anti-human Ki-67 antigen (Dako,Glostrup, Denmark), monoclonal mouse anti-humanP53 protein (Dako, Glostrup, Denmark).Immunohistochemicalanalysis of P53 and Ki67 expression was performed. Every nuclei stained brown,regardless of shade intensivity, was considered positive. The interpretation of immunohistochemicalstaining was expressed as number of positive cells in 100 cell count in most active area of the slide.Non-parametric analysis of variance Kruskal-Walistest was performed.P53 expressionExpression of P53 was negative in 24/24 ordinary uterine leiomyoma, 2/10 mitotic activity leiomyoma,11/15 cellular leiomyoma. Expression of P53 in 1–10% of cells showed 3/10(30%) mitotic activeleiomyoma and 1/15(6.6%) cellular leiomyoma. Expression in 10-70% of cells showed 5/10(50) mitoticactivity leiomyoma, 3/15(20%) cellular leiomyoma. A significant difference in expression of P53 wasseen between ordinary and proliferative (mitotic activity and cellular) uterine leiomyoma (p<0.007, Table1).Ki-67 expressionExpression of Ki67 was negative in 20/20 (100%) ordinary leiomyoma, 4/11(36.3%) mitotic activityleiomyoma and 7/18(38.8%) cellular uterine leiomyoma. 1–10% of cells were positive in 4/11 (36.6%)mitotic activity leiomyoma, and 5/18% cellular leiomyoma. Expression was positive in 10-70%of cellsof 3/11(27.2%) mitotic activity leiomyoma and 6/18(33.3%). Statistically significant differences in Ki67expression was found between ordinary leiomyoma and proliferating leiomyoma (p<0.014, Table 2) andbetween LM and LMS (p=0.000, Table 1).Conclusion:The findings of our study in concordance with other study results are helpful information establishingmore diagnostic criteria and parameters for diagnosis in doubtful cases between two entities.Immunoassaying for Ki-67 and P53 are such parameters. The panel of their expression in specific caseeases diagnosis.