Prognostic significance of claudin-1 expression in renal cell carcinoma

Purpose Renal cell carcinoma (RCC) is the most common renal cancer in adults comprising ∼3% of all human malignancies. Claudin-1 is a tight junction protein widely expressed in liver and kidney tissue. The role of claudins in cancer has not been clearly defined. We aimed to assess the prognostic significance of claudin-1 expression in RCC. Patients and methods Immunohistochemical staining for 51 RCCs was performed, and the results were correlated with clinical, histopathologic, and prognostic parameters. Results Claudin-1 was expressed in 52.9% of RCC cases. Only 46.7% of conventional RCCs were positive for claudin-1, whereas 68.75% of papillary RCCs showed positive claudin-1 expression. Claudin-1 expression was associated with markers of unfavorable tumor biology in conventional and papillary RCC. Claudin-1 positivity was a prognosticator of shortened patient survival in conventional and papillary RCC ( P =0.06 and 0.007, respectively). Conclusion Upregulation of claudin-1 was associated with dedifferentiation, aggressiveness, and shortened patient survival in RCC.