Molecular diagnosis and therapy of kidney cancer.

Kidney cancer is not a single disease; it is made up of a number of cancers that occur in the kidney, each having a different histology, following a different clinical course, responding differently to therapy, and caused by a different gene. Study of the genes underlying kidney cancer has revealed that it is fundamentally a metabolic disorder. Understanding the genetic basis of cancer of the kidney has significant implications for diagnosis and management of this disease. VHL is the gene for clear cell kidney cancer. The VHL protein forms a complex that targets the hypoxia-inducible factors for ubiquitin-mediated degradation. Knowledge of this pathway provided the foundation for the development of novel therapeutic approaches now approved for treatment of this disease. MET is the gene for the hereditary form of type 1 papillary renal carcinoma and is mutated in a subset of sporadic type 1 papillary kidney cancers. Clinical trials are currently ongoing with agents targeting the tyrosine kinase domain of MET in sporadic and hereditary forms of papillary kidney cancer. BHD is the gene for the hereditary type of chromophobe kidney cancer. It is thought to be involved in energy and/or nutrient sensing through the AMPK and mTOR signaling pathways. Hereditary leiomyomatosis renal cell carcinoma, a hereditary form of type 2 papillary renal carcinoma, is caused by inactivation of a Krebs cycle enzyme due to mutation. Knowledge of these kidney cancer gene pathways has enabled new approaches in the management of this disease and has provided the foundation for the development of targeted therapeutics.