Expression of Ki-67, P53 and progesterone receptors in uterine smooth muscle tumors. Diagnostic value.

Aim was to investigate expression of Ki-67, P53 and progesterone receptors (PR) in leiomyomas (LM), smooth muscle tumors of uncertain malignant potential (STUMP) and leiomyosarcomas (LMS) and to establish possible usefulness of these three parameters in distinguishing between LM and STUMP and STUMP and LMS. Retrospective study of 51 uterine smooth muscle neoplasm (16 LM, 18 STUMP, 17 LMS) technically acceptable for analyses from years 2002-2007 from Department of Gynecological and Prenatal Pathology, University Hospital Center Zagreb, Croatia. Immunohistochemical analysis of Ki-67, P53 and PR expression was performed. Every nuclei stained brown, regardless of shade intensivity, was considered positive. The interpretation of immunohistochemical staining was expressed as number of positive cells in 100 cell count in most active area of the slide. Non-parametric analysis of variance Kruskal-Walis test was performed. Ki-67 expression was negative in all LM and higher than 5% in 12/18 STUMP and 10/17 LMS. Significant differences were observed between LM and STUMP expression for Ki-67 (p = 0.000), and LM and LMS expression for Ki-67 (p = 0.000). There was no expression of P53 in LM, expression of P53 was found in 7/17 LMS and 5/18 STUMP Expression of P53 was significant between LM and LMS (p = 0.002), and between LM and STUMP (p = 0.006). Expression of PR was found in 16/16 LM and 18/18 STUMP 10/17 LMS did not show PR expression. Expression of PR was significant between LM and LMS (p = 0.018) and STUMP and LMS (p = 0.004). The findings of our study in concordance with other study results are helpful information establishing more diagnostic criteria and parameters for diagnosis in doubtful cases between three entities. Immunoassaying for Ki-67, P53 and PR are such parameters. The panel of their expression in specific case eases diagnosis.