The gene expression patterns of kidney cancers distinguish different types of cancers and identify cancers that have spread beyond the kidney, according to a study published in the journal Clinical Cancer Research.
The kidneys are a pair of bean-shaped organs located on each side of the spine. The kidneys filter the blood and eliminate waste in the urine through a complex system of filtration tubules. All of the blood in the body passes through the kidneys approximately 20 times an hour. Renal cell cancer (RCC) is the most common type of kidney cancer. It is characterized by the presence of cancer cells in the lining of the filtration tubules of the kidney.
Gene expression profiling, a laboratory technique, offers promise for guiding the diagnosis and treatment of cancers including kidney cancer. This technique tests cancer cells for specific patterns in their gene activity or in proteins produced by the genes. The identified patterns tend to be strongly associated with a specific type of cancer and specific characteristics of the cancer. These characteristics include aggressiveness or response to therapy.
To determine whether gene expression distinguishes different types of kidney cancer from normal tissue and if different genes are expressed at different stages of kidney cancer development, researchers evaluated two types of kidney tumors (49 RCC and 20 non-RCC) and 23 normal kidney samples. Researchers found that specific gene “signatures” identified the two types of tumors. Furthermore, they found that different genes were expressed at early and late stages of tumor development and that a specific pattern of expression accurately identified tumors that had metastasized (spread beyond the kidney).
The researchers conclude that the gene expression of kidney cancers provides information about the type and extent of the cancer. Since gene expression identified patients with metastatic disease, the researchers state that gene expression profiling “has the potential, if prospectively validated, to enrich the armamentarium of diagnostic tests” in kidney cancer. In other words, gene expression profiling may become a valuable contribution to the diagnostic process in kidney cancer.
Reference: Jones J, Otu H, Spentzos D et al. Gene signatures of progression and metastasis in renal cell cancer. Clinical Cancer Research. 2005;11:5730-5739.