Renal Cancer Biomarkers

Renal cell carcinoma (RCC) is a form of kidney cancer that involves malignant transformation of cells of the renal tube. It is the most common type of kidney cancer in adults. RCC accounts for ~3% of adult malignancies and 90-95% of neoplasms arising from the kidney. In the US >32,000 new cases of RCC are diagnosed every year, and ~12,000 persons die from the disease annually. RCC metastasizes easily, often spreading to the lungs and other organs. In cases where metastatic disease is not yet present at time of diagnosis, the 5-year survival rate for RCC patients is 60-75%. However, metastases are already present at diagnosis in nearly one-third of RCC cases. In cases where the tumor has metastasized to the lymph nodes, the 5-year survival rate is reduced to 5-15% and further to <5% when the cancer has spread to other organs.

Gene Expression Profile of RCC for Biomarkers

The WHO system defines histopathologic tumor subtypes of RCC with distinct clinical behavior and underlying genetic mutations. In adults, the common malignant subtypes are variants of RCC. RCC has a poor prognosis and unpredictable course and to date there are no molecular markers that reliably predict RCC outcome. Histopathologic classification of RCC is critical for clinical management of RCC, but is becoming more complex with recognition of novel tumor subtypes, development of procedures yielding small diagnostic biopsies, and emergence of molecular therapies directed at tumor gene activity. Therefore, classification systems based on gene expression are likely to become essential for diagnosis, prognosis and treatment of kidney tumors. DNA microarray studies have shown that clinically relevant renal tumor subtypes are characterized by distinct gene expression profiles, which are useful for discovery of novel diagnostic and prognostic biomarkers.