Prognostic value of the endothelial activation and stress index in patients with upper tract urothelial cancer undergoing radical nephroureterectomy

Purpose: The relationship with endothelial activation and stress index (EASIX), which represents the degree of endothelial dys-function, is unwell known in upper tract urothelial carcinoma (UTUC). The present study aims to assess the prognostic value of the EASIX for recurrence-free survival (RFS) and overall survival (OS) in patients with UTUC who underwent radical nephroureterec-tomy (RNU).Materials and Methods: We retrospectively reviewed the clinical data of 627 patients with UTUC who underwent RNU without neoadjuvant chemotherapy at three hospitals between 2002 and 2019. EASIX scores were calculated using the formula "serum lac-tate dehydrogenase (U/L)xcreatinine (mg/dL) /platelet count (109/L)" and evaluated based on log2-transformed values. We divided the patients according to the EASIX score (>1.27 vs. <= 1.27).Results: Among 627 patients, 380 were finally analyzed. Using maximally selected log-rank statistics, the optimal EASIX cutoff value was 1.27 on the log2 scale. The baseline characteristics were similar between the two groups except for age. The high EASIX score group had worse RFS and OS than the low EASIX score group (log-rank p=0.001 and p=0.006, respectively). At 5 years, the mean RFS and OS difference between the low and high EASIX score groups was 11.1 and 7.35 months, respectively. High EASIX score remained a key prognosticator of RFS and OS after RNU in multivariable analysis. Conclusions: EASIX score may represent endothelial dysfunction in patients with UTUC and may serve as a readily available prog-nostic factor for oncologic outcomes.