Effect of paracentesis on the survival of patients with terminal cancer and ascites: a propensity score–weighted analysis of the East Asian Collaborative Cross-cultural Study to Elucidate the Dying Process

Purpose: Paracentesis is among the most widely utilized treatments for malignant ascites (MA). However, paracentesis in patients with MA has the potential to be associated with life-shortening effects. Thus, this study aimed to investigate whether paracentesis affected the duration of survival in such patients. Methods: We performed a post hoc analysis of a prospective multicenter observational study investigating the dying process and end-of-life care in patients with terminal cancer, admitted to 23 palliative care units in Japan. Survival duration was compared between patients who did (paracentesis group) and did not undergo paracentesis (non-paracentesis group). We used inverse probability of treatment weighting (IPTW) to control for baseline covariates between groups. Results: Among the 1896 initially enrolled patients, 568 with ascites were included in the study cohort. Eighty-five (15.0%) patients underwent paracentesis. The primary tumor site was the pancreas (51.9%, n = 295), followed by the gastrointestinal tract (22.7%, n = 129). Non-adjusted median durations of survival were 22 days (95% confidence interval [CI]: 16–25) and 12 days (95% CI: 11–13) in the paracentesis and non-paracentesis groups, respectively (hazard ratio [HR]: 0.69, 95% CI: 0.54–0.88; p = 0.003). The IPTW-adjusted median survival durations were 22 (95% CI: 16–25) and 16 days (95% CI: 12–22) in the paracentesis and non-paracentesis groups, respectively (HR: 0.89, 95% CI: 0.64–1.24; p = 0.492). No serious adverse events occurred in the paracentesis group. Conclusions: Paracentesis does not negatively affect the survival of patients with cancer and MA and can be a standard treatment in palliative care settings.