EP475\u2005Immunohistochemical expression of LHRH receptor in different anatomical compartments of endometrial cancer patients

Abstract

Introduction/Background Endometrial cancer is the most common gynaecologic malignancy in developed countries. Despite good overall prognosis, still many patients recur within first 3 years after primary treatment. Recently, new targeted treatment with doxorubicin linked to an LHRH agonist was investigated in phase III trial in patients with locally advanced, recurrent or metastatic endometrial cancer. Unfortunately, this receptor-mediated targeted chemotherapy, despite promising phase II results, showed no benefits comparing to standard treatment. To explain the possible rationale of such unexpected results we decide to assess LHRH receptor (LHRH-R) expression in different compartments of female genital tract in patients with endometrial cancer. Methodology Among 100 patients operated due to endometrial cancer in our centre, 92 cases with endometrioid adenocarcinoma were chosen. Immunohistochemical LHRH-R expression in postoperative paraffin-embedded tissue blocks was evaluated in endometrial cancer, ovarian cortex, ovarian medulla, and oviduct tissue. In 10 patients it was also possible to assess LHRH-R expression in areas of endometrial hyperplasia diagnosed concurrently with cancer. The standard semi-quantitive scoring system considering staining intensity and area extent according to Allred was used for expression assessment. The results were presented as negative, moderate and strong expression. Pearson’s chi-square test was used to assess differences in analysed groups. Results LHRH-R expression was detected in all compartments studied. Strong expression was found in 77% of endometrial cancer, 61% of ovarian cortex, 28% of ovarian medulla, 85% of fallopian tube, and 7% of endometrial hyperplasia. LHRH-R expression in ovarian medulla was significantly decreased when compared to cancer compartment (p=0,04). Additionally, LHRH-R expression in ovarian cortex was almost significantly decreased when compared to cancer compartment (p=0,06). There was no differences between all other compartments analysed. Conclusion Due to observed differences in LHRH-R expression, targeted treatment with chemotherapeutic agents linked to an LHRH agonist may show no benefits in all patients with locally advanced endometrial cancer patients. Disclosure Nothing to disclose.