Somatic VHL alteration and its impact on prognosis in patients with clear cell renal cell carcinoma

4602 Backgrounds: Somatic inactivation of the von Hippel-Lindau (VHL) gene is the most frequent genetic event observed in clear cell renal cell carcinomas (CC-RCCs). However, the prognostic relevance of somatic VHL alteration and its target, hypoxia inducible factor (HIF)-1α, has not been defined. We investigated the genetic changes in the VHL gene and HIF-1α and studied their clinical implications in patients with sporadic CC-RCC. Methods: Patients who underwent nephrectomy were eligible if they had pathologically confirmed CC-RCC that was not associated with VHL disease or familial RCC. Tumor tissues were selected from paraffin blocks on the basis of hematoxylin and eosin (H&E)-stained sections. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis was performed to detect VHL mutations and genetic changes in HIF-1α, which were followed by automated direct sequencing. VHL hypermethylation was examined by methylation-specific PCR. Results: A total of 56 patients were enroll...