Calgranulin A (S100A8) Immunostaining: A Future Candidate for Risk Assessment in Patients with Non-Muscle-Invasive Bladder Cancer (NMIBC)

INTRODUCTION: There is an urgent need to identify patients with bladder cancer (BC) who are at high risk of recurrence or progression. Calgranulin A is a strong marker for muscle-invasive or advanced BC and recent studies have shown its potential for identifying patients at risk even in non-muscle-invasive bladder cancer (NMIBC). The present study examines risks of recurrence and progression dependent on immunostaining with calgranulin A in NMIBC. METHODS: Calgranulin A protein expression was evaluated through the immunohistochemistry of 158 randomly selected, transurethrally resected BC specimens of separate patients (pTa 89, pT1 69) using tissue microarrays. Kaplan–Meier survival analysis and Cox regression were performed to determine whether calgranulin A expression is associated with recurrence-free survival (RFS), progression-free survival (PFS), or cancer-specific survival (CSS). RESULTS: Calgranulin A expression is significantly different between pTa and pT1 tumors (p = 0.000, Mann–Whitney U test) and between tumor grades (p = 0.015, Kruskal–Wallis test). Kaplan–Meier estimates produced significant results for low and high calgranulin A expression concerning RFS [5y-RFS 70.4 ± 4.0% vs. 35.9 ± 12.5%, median RFS not reached (NR) vs. 12.0 ± 4.4 month, p = 0.029, log-rank test], PFS (5y-PFS 90.3 ± 2.7% vs. 51.5 ± 14.0%, median PFS NR in both groups, p = 0.000, log-rank test), and CSS (5y-CSS 92.9 ± 2.6% vs. 70.7 ± 12.4%, median CSS NR in both groups, p = 0.005, log-rank test). Calgranulin A remained an independent factor for RFS (p = 0.024, HR 2.43) and PFS (p = 0.002, HR 5.92) according to the multivariate Cox regression model. CONCLUSIONS: Calgranulin A expression in NMIBC, detected through immunohistochemistry, is a promising marker for the identification of NMIBC patients at high risk of recurrence and progression.