Overexpression of MAGE-A2 is Related to the Malignant Degree and Progression of Disease in Patients With Clear Cell Renal Cell Carcinoma.

Melanoma antigen gene-A2 (MAGE-A2) is one of the most cancer-testis antigens overexpressed in a variety of malignancies. However, the expression of MAGE-A2 for clinical values in the pathophysiology of renal cell carcinoma (RCC) is unknown. For the first time, the present study was conducted to examine the expression and prognostic significance of MAGE-A2 expression in clear cell RCC (ccRCC). MAGE-A2 expression was assayed in 162 well-defined ccRCC samples using immunohistochemistry staining on tissue microarrays. The association between MAGE-A2 expression and clinic-pathologic features as well as survival outcomes were then performed. A significant and positive correlation was found between cytoplasmic expression of MAGE-A2 with tumor size (P=0.008), nucleolar grade (P =0.001), tumor stage (P =0.001), microvascular invasion (P=0.001), invasion to renal pelvis (P=0.032), renal sinus fat (P=0.004), and Gerota's fascia (P=0.028) as well as histologic tumor necrosis (P<0.0001). Increased expression of MAGE-A2 was observed to be associated with shorter progression-free survival (PFS) compared with patients with low expression of MAGE-A2 (P=0.032). Multivariate analysis revealed that tumor size and nucleolar grade are independent predictors of the PFS (P=0.054, P=0.032, respectively). Our results indicated that increased cytoplasmic expression of MAGE-A2 is associated with the malignant degree and progression of ccRCC. This data improved the significance of MAGE-A2 expression and will potentially allow using MAGE-A2 for the prognosis of the disease and immunotherapy in patients with ccRCC.