Impacts of fluid retention on prognostic abilities of cachexia diagnostic criteria in cancer patients with refractory cachexia

Abstract

Background & aims: The international cancer cachexia criteria with a cutoff of 5% weight loss (WL) was proposed in Western patients. The Asian Working Group for Cachexia (AWGC) developed new criteria in Asian patients. The AWGC criteria are not cancer-specific and employ a cutoff of 2% WL. However, it is unclear whether both criteria are useful in patients with very advanced cancer because WL can be underestimated owing to fluid retention. Therefore, this study aimed to investigate the impacts of fluid retention on the prognostic abilities of both criteria in cancer patients with weeks of survival.

Methods: This study involved a secondary analysis of a prospective cohort study. The inclusion criteria constrained the study to adult patients with advanced cancer. Patients were divided into Non-cachexia and Cachexia groups using the international criteria and AWGC criteria. We performed time-to-event analyses using the Kaplan-Meier method and log-rank tests, and by conducting univariate and multivariate Cox regression analyses.

Results: A total of 402 patients were included in the analysis. Using the international criteria, the p-values for the log-rank test and stratified log-rank test for the mixed patients with and without fluid retention were 0.55 and 0.18, respectively. Using the AWGC criteria, the p-values for the log-rank test and stratified log-rank test for the mixed patients with and without fluid retention were 0.38 and 0.12, respectively. Without considering the impacts of fluid retention, no significant differences were observed between the Non-cachexia and Cachexia groups for both criteria. After adjusting for the status of fluid retention, significantly higher risks of mortality were not observed in the Cox proportional hazard model for the Cachexia group compared with the Non-cachexia group, for both criteria. However, significant associations were observed between fluid retention and overall survival.

Conclusions: The international criteria and AWGC criteria lost their prognostic abilities in cancer patients with weeks of survival. Since measurements of %WL were significantly confounded by fluid retention, fluid retention-adjusted criteria for cachexia need to be developed for cancer patients with refractory cachexia.

Keywords: Cachexia; Cancer; Criteria; Fluid retention; Palliative care; Prognosis.