Background: The purpose of this study was to provide an immunocytochemical evaluation of the expression of receptors for estrogens (ER) and progesterone (PgR), and of Ki67 and PCNA (proliferating cell nuclear antigen) proliferation antigens in uterine myomata cells in three groups of patients operated in various phases of the menstrual cycle, and to determine the relationship between the expression of the receptors, the proliferative activity of myoma cells, and the phase of the menstrual cycle during which the tumor was excised
Material/Methods: The studies were performed on samples of uterine 85 leiomyomata. Twelve of the patients were operated in the follicular phase of menstrual cycle, 50 in the luteal phase, and 27 in the post-menopausal period. The receptors and proliferating antigens were detected immunocytochemically. The intensity of the immunocytochemical reaction was evaluated using the ImmunoReactive Score (IRS).
Results: In all three groups of patients the expression of PgR significantly exceeded that of ER. Also, in all the patients the mean expression of PCNA significantly exceeded the expression of Ki76.
Conclusions: The expression of the studied antigens did not depend upon the phase of the menstrual cycle, and was similar in the postmenopausal period.

Keywords: uterine myomata, estrogen receptor, progesteron receptor, PCNA, Ki67