Background: Melanoma-associated antigen-A (MAGE-A) and programmed-death ligand 1 (PD-L1) are present in urothelial carcinoma (UC). We assessed survival outcomes in patients with MAGE-A and PD-L1 expression.
Methods: MAGE-A and PD-L1 expression on neoplastic cells was analyzed using tissue microarrays from patients with UC. We compared differential expression between disease stage and grade. MAGE-A and PD-L1 co-expression was subcategorized. Fisher's exact test was done for categorical variables followed by univariable and multivariable analysis of recurrence-free survival (RFS) and progression-free survival (PFS).
Results: Co-expression of MAGE+/PD-L1+ was higher in advanced disease; however, only MAGE+/PD-L1- was associated with shorter RFS [hazard ratio (HR) 1.89; 95% confidence interval (CI) 1.19-2.99; p = .006]. MAGE+/PD-L1+ was associated with the worst PFS (HR 17.1; 95% CI 5.96-49.4; p ≤ .001). MAGE-A expression was more prevalent with high-grade (p = .015), and higher-stage ≥ pT2 (p = .001) disease. The 5-year RFS was 44% for MAGE+ versus 58% for MAGE- patients. On multivariable analysis, MAGE+ was also associated with shorter RFS (HR 1.55; 95% CI 1.05-2.30; p = .03). Similarly, MAGE+ was associated with shorter PFS (HR 3.12; 95% CI 1.12-8.68; p = .03).
Conclusion: MAGE-A and PD-L1 expression is increased in advanced disease and associated with shorter PFS. Furthermore, MAGE-A expression was significantly associated with higher-grade and -stage disease and associated with shorter RFS and PFS. The worse prognosis associated with MAGE-A+/PD-L1+ provides evidence that a combinatorial treatment strategy co-targeting MAGE/PD-L1 might be feasible. Further studies are needed to validate these findings.
Keywords: Melanoma-associated antigen; Programmed death-ligand 1; Survival; Tissue microarray; Urothelial carcinoma.