Tinzaparin And Biomarkers After Neoadjuvant Treatment of Ovarian Cancer

This is an open randomized controlled clinical pilot trial (Phase II). The study includes women with the International Federation of Obstetrics and Gynecology (FIGO) stage III-IV EOC selected for neoadjuvant chemotherapy (NACT) and without signs of thromboembolic disease or ongoing treatment of thromboembolic disease. The women will be allocated 1:1 to treatment with tinzaparin 4500 IU/8000 IU (dose depending on woman's weight) subcutaneously once daily or no tinzaparin. The treatment group starts tinzaparin when the primary treatment (chemotherapy) starts. The control group will not receive tinzaparin or other low molecular weight heparin preparations. The NACT consists of carboplatin and paclitaxel, given according to the standard regimen with cycle repeats every 21 days. Pre-treatment, before every cycle of chemotherapy, before delayed primary debulking surgery (DPDS) and three weeks after the last cycle of chemotherapy venous blood samples will be taken for measuring the biomarkers hemoglobin, platelets, leucocytes, C-reactive protein (CRP), albumin, cancer antigen-125 (CA-125), Tissue Factor, D-dimer, soluble P-selectin, thrombin-antithrombin complex and thrombin generation potential. Furthermore, a panel of 92 inflammation-associated proteins will be analyzed by a by a high-sensitivity Proximity Extension Assay at baseline, visit 5 and visit 8 or 9. After three cycles of NACT, the patient will be evaluated clinically and with imaging diagnostics in order to determine whether the patient should undergo DPDS. In the investigators´ setting, \> 80% of patients receiving NACT for EOC undergo DPDS. After DPDS, all patients will be treated with tinzaparin for 28 days according to clinical practice concerning postoperative thromboembolic prophylaxis and thereafter continue the chemotherapy for additional two-three courses. The participants who were allocated to tinzaparin during the NACT can chose to continue the tinzaparin after ending the postoperative thromboembolic prophylactic tinzaparin treatment for additional 2-3 courses. The biomarkers will be measured preoperatively and four weeks postoperatively after DPDS and then before each course of chemotherapy given during the primary treatment. The women who do not undergo surgery will remain included in the study for the following three cycles of chemotherapy. Thus, the total study period constitutes 22-29 weeks.