974 Hormonal receptors expression in uterine leiomyosarcomas

Introduction/Background* Uterine leiomyosarcoma (ULS) is a rare tumor, accounting for less than 2% of uterine cancers. Its prognosis is poor because of its aggressiveness and its poor response to chemotherapy and radiation therapy. The evaluation of anatomo-pathologic conventional parameters, particularly the FIGO stage, is insufficient to predict their evolutionary profile. to better understand, the biology of these tumors is needed to assess prognosis and adapt therapeutic management. Methodology This is a retrospective study of 29 cases of ULS from the Department of Pathological Anatomy and Cytology of Salah Azaiez Institute of Tunis over 17 years (2004 -2020). The expression of estrogenic and progesterone receptors (RO and RP) was studied by immunohistochemistry (automate BOND MAX leica). Immunolabelling was assessed for the entire tumor and we established the average. The threshold of positivity chosen was 10% regardless of the intensity. Result(s)* The mean age medium was 52 years [min 39 – max 70 years]. Tumors were stage I in 48%, stage II in 14%, stage III in 24%, and stage IV in 14% of cases. We found co-expression of RO and RP in 11 cases, expression of ER only in 3 cases, expression of PR only in 4 cases, and lack of expression of both markers in 11 cases. The breakdown by FIGO stage was as follows: RO+ tumours 22%, 11%, 56% and 11%, RP+ tumours 30%, 20%, 50% and 0%. We did not find a correlation between stage and expression of RO or RP. Conclusion* We did not find a correlation between the hormonal receptor expression and stage. The place of hormonotherapy, which is increasingly used in other uterine sarcomas such as endometrial stromal sarcoma, remains to be clarified by large-scale clinical trials.