Galectin-9 As a Prognostic and Predictive Biomarker in Bladder Urothelial Carcinoma

Purpose: Galectin-9, a member of the "tandem repeat" type galectins performing as animal lectins with an affinity for β-galactosides, has been well documented to exert crucial functions in immunomodulation, survival, and growth of various tumors. This study aims to reveal the clinical significance of galectin-9 in urothelial carcinoma of the bladder (UCB) postoperatively.

Materials And Methods: We retrospectively included 202 patients with UCB who underwent radical cystectomy at a single institute from 2002 to 2014. Galectin-9 expression was assessed by immunohistochemistry on tissue microarrays. The Kaplan-Meier method was conducted to plot survival curves. Prognostic nomograms were constructed via integrating all the independent indicators from multivariate Cox analysis for recurrence-free survival (RFS) and cancer-specific survival (CSS). In addition, we evaluate whether patients with increased or decreased galectin-9 expression might benefit from adjuvant chemotherapy.

Results: Low galectin-9 expression was significantly correlated with lymphovascular invasion (P = 0.002), early recurrence (P = 0.010), and short CSS (P = 0.002). Furthermore, multivariate analysis identified galectin-9 expression as a potential independent indicator for RFS (hazard ratio = 0.62; 95% CI: 0.40-0.95; P = 0.030) and CSS (hazard ratio = 0.46; 95% CI: 0.26-0.81; P = 0.008). Moreover, the benefit associated with adjuvant chemotherapy was superior among galectin-9 low patients than among galectin-9 high patients (P = 0.014).

Conclusions: Expression of galectin-9 is an independent prognostic factor for RFS and CSS in patients with UCB. Evaluation of galectin-9 expression may predict the benefit from adjuvant chemotherapy.