Effects of reinfusion of ascitic fluid in malignant ascites: A nationwide claims-based cohort study.

Abstract

Malignant ascites causes substantial symptom burden in advanced cancer. Repeated drainage may accelerate protein loss and ascitic fluid re-accumulation. Cell-free and concentrated ascites reinfusion therapy (CART) returns concentrated proteins to patients, but comparative efficacy data remain scarce. To compare CART with paracentesis alone for overall survival and repeat ascites drainage in patients with malignant ascites. This nationwide retrospective cohort study used the Japanese National Database of Health Insurance Claims and Specific Health Checkups. We identified adults with cancer who underwent CART or paracentesis within the last year of life between April 2013 and March 2016. Patients receiving CART as the first drainage procedure were compared with those receiving paracentesis alone. Outcomes were overall survival and repeat drainage, with prespecified subgroup analyses by tumor site and liver metastases. Of 638,626 cancer decedents, 52,625 underwent ascites drainage within the last year of life. Of these, 10,654 received CART initially, and 37,272 received paracentesis alone. Median overall survival was 31 vs. 28 days (adjusted hazard ratio, 0.97; 95%CI, 0.95-0.99), indicating no clinically meaningful survival benefit with CART. CART was associated with a lower repeat drainage rate (adjusted hazard ratio, 0.73; 95%CI, 0.72-0.74), consistent with longer observed intervals between drainage procedures (median, 15 vs. 8.3 days). The reduction appeared greater in patients with hepatocellular carcinoma or liver metastases. CART was associated with lower rate of repeat drainage but no meaningful survival prolongation compared with paracentesis alone. CART may reduce repeat drainage, particularly in patients with liver-dominant diseases.