The Association Between Extracellular Water-to-Total Body Water Ratio and Therapeutic Durability for Advanced Lung Cancer.

BACKGROUND/AIM Extracellular water-to-total body water ratio (ECW/TBW) measured by bioelectrical impedance analysis (BIA) reportedly predicts clinical outcomes of various diseases. The aim of this retrospective study was to examine the association between ECW/TBW and therapeutic durability of chemotherapy and/or immune checkpoint inhibitors in advanced lung cancer. PATIENTS AND METHODS Patients with advanced lung cancer underwent BIA before chemotherapy and/or treatment with immune checkpoint inhibitors at our hospital between June 2018 and November 2019. RESULTS Of 75 patients, 18 with ECW/TBW ≥0.4 were assigned to the overhydrated group (OH-G) and 57 patients ECW/TBW <0.4 were assigned to the non-overhydrated group (NOH-G). The median time-to-treatment failure was significantly shorter in the OH-G than in the NOH-G (p=0.003). Multivariate analysis revealed that ECW/TBW ≥0.4 predicted treatment failure [hazard ratio (HR)=2.508, 95% confidence interval (CI)=1.19-5.27; p=0.01]. CONCLUSION The ECW/TBW may be an objective parameter for predicting therapeutic durability in advanced lung cancer.