CXCR2 expression is associated with prostate-specific membrane antigen expression in hepatocellular carcinoma: reappraisal of tumor microenvironment and angiogenesis

Purpose: Angiogenesis is a critical component of neoplastic progression, and inflammatory cells within the tumor microenvironment contribute to neoangiogenesis. Prostate-specific membrane antigen (PSMA) is expressed in the neovasculature of various solid tumors, including hepatocellular carcinoma (HCC). Also, CXCR2 + inflammatory cells, including CD15 + neutrophils, play crucial roles in HCC progression. We evaluated the associations between PSMA expression and CXCR2 + inflammatory cells in HCC by immunohistochemistry (IHC). Methods: CXCR2 expression and its correlation with PSMA, the PSMA/CD34 ratio, immune markers (CD3, CD15, CD68, and CD163), clinical parameters, and oncologic outcomes were evaluated in 76 HCC and background benign liver tissue. Results: PSMA and the PSMA/CD34 ratio showed a positive correlation with intratumoral CXCR2, but not with intratumoral CD15. Intratumoral CXCR2 + cell count was positively associated with intratumoral CD3, CD15, CD68, and CD163 expression levels. In the benign compartment, CXCR2 was significantly associated with CD15. Metabolic dysfunction-associated steatotic liver disease (MASLD) risk factors and cirrhosis had an opposite effect on CXCR2 + cell count in benign liver tissue. Higher CD15 + cell count in the benign liver was associated with decreased overall survival (OS) and recurrence-free survival (RFS). Conclusions: In HCC, intratumoral CXCR2 + cell count is associated with PSMA expression. Intratumoral and benign compartments had different CXCR2 + inflammatory cell makeup. The immune microenvironment of HCC appears to differ depending on underlying risk factors. Further investigations are warranted to elucidate PSMA biology and assess the potential utility of CXCR2 IHC in PSMA-targeted theranostics.