Feasibility of a fast-track randomized controlled trial of cell-free and concentrated ascites reinfusion therapy for patients with refractory malignant ascites

BACKGROUND: Malignant ascites often causes discomfort in advanced cancer patients. Paracentesis is the most common treatment modality, but it requires frequently repeated treatment. Cell-free and concentrated ascites reinfusion therapy (CART) may prolong the paracentesis interval, but controlled trials are lacking. We assessed the feasibility of a randomized controlled trial of CART vs. paracentesis alone for patients with refractory malignant ascites. METHODS: This study was an open-label, fast-track, randomized controlled, feasibility trial. Patients admitted to four designated cancer hospitals who received no further anticancer treatments were eligible. Patients were randomly assigned 1:1 to a CART arm or control (simple paracentesis) arm. The feasibility endpoint was the percentage of patients who completed the study intervention. Secondary endpoints included paracentesis-free survival, patient’s request on the questionnaire for paracentesis (PRO-paracentesis)-free survival (the period until the patients first reported that they would want paracentesis if indicated), and adverse events. RESULTS: We screened 953 patients for eligibility. Of 61 patients with refractory malignant ascites, 21 patients were determined as eligible. Finally, 20 patients consented and were allocated; 18 patients (90%, 95% CI: 68.3–98.8) completed the study intervention. All patients had an ECOG performance status of 3 or 4. The median drained ascites volume was 3,200 mL in the CART arm and 2,500 mL in the control arm. In the CART arm, the median reinfused albumin volume was 12.6 g. Median paracentesis-free survivals were 5 days (95% CI: 2–6) in the CART arm, and 6 days (3–9) in the control arm. Median PRO-paracentesis-free survivals were 4 days (2–5) and 5 days (1–9), respectively. A total of 73% of patients received paracentesis within 2 days from their first request for the next paracentesis. One patient in the CART arm developed Grade 1 fever. CONCLUSIONS: A fast-track randomized controlled trial of CART for patients with malignant ascites is feasible. The efficacy and safety of CART should be assessed in future trials. PRO-paracentesis-free survival may be a complementary outcome measure with paracentesis-free survival in future trials. TRIAL REGISTRATION: Registered at University Hospital Medical Information Network Clinical Trial Registry as UMIN000031029. Registered on 28/01/2018. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12885-022-09336-3.