Diagnostic roles of MUC1 and GLUT1 in differentiating thymic carcinoma from type B3 thymoma

MUC1 is a transmembrane mucin that has been related to tumor progression and outcome in various malignancies. GLUT1 is a member of the mammalian facilitative glucose transporter (GLUT) family of passive carriers that functions as an energy-independent system for transporting glucose. Both of them are useful markers for the diagnosis, progression, and prognosis of various tumors, especially those that are cancerous. However, the clinical significance of MUC1 and GLUT1 in thymic epithelial tumors remains uncertain due to a lack of quality specimen and studies at sufficient scale, both owing, in part, to the rarity of the tumors. The aim of this article is to study the expression patterns of MUC1 and GLUT1 in thymic carcinoma and type B3 thymoma, and to evaluate their diagnostic value for these two types of tumors via immunohistochemistry. Forty-three patients were included in the study, including twenty-two with thymic carcinoma and twenty-one with type B3 thymoma. Tumor tissue sections were immunohistochemically stained for MUC1 and GLUT1; meanwhile, some tumors were also stained with CKpan, TDT, CD5, and CD117. MUC1 was expressed in a total of 17 cases, with a positive rate of 77.27% (17/22) in thymic carcinoma and 9.52% (2/21) in type B3 thymoma, revealing a significant difference (p<0.0001). A significant difference (p<0.0001) was also shown for GLUT1, where the positive rates for thymic carcinoma and type B3 thymoma were 100% (22/22) and 42.86% (9/21), respectively. The expression of MUC1 was significantly correlated with GLUT1 (p<0.0001). Furthermore, GLUT1 staining sensitivity and specificity for thymic carcinoma were 100% (22/22) and 70.97% (22/31), respectively, while MUC1 staining sensitivity and specificity were 77.27% (17/22) and 89.47% (17/19), respectively. In conclusion, our study shows that MUC1 and GLUT1 staining may play a useful role in differentiating thymic carcinoma from type B3 thymoma, with high sensitivity and specificity.