Quantitative assessment of tumor immune microenvironment in context of HER2 expression in MIBC

The study examined the relationship between HER2 status and tumor immune microenvironment in 62 patients with muscle-invasive bladder cancer (MIBC) who received neoadjuvant chemotherapy (NAC) before surgery. HER2 expression 2+/3+ was detected in 45% of tumors and 0/1+ in 55% of tumors. Response to NAC was similar in both groups - 32% in patients with HER2 0/1+ and 32% in patients with HER2 2+/3+. Analysis of immune cells (CD3+, CD20+, CD68) showed no significant differences between groups according to HER2 status. PD-L1 expression was not associated with HER2 status. Overall survival did not differ between groups with different HER2 values. The findings suggest that HER2 expression 2+/3+ occurs in a substantial proportion of MIBC but is not associated with NAC response or overall survival.