Genetic characterization of multifocal tumor growth in renal cell carcinoma

The primary cancer found in the kidney is renal cell carcinoma (RCC), which does not as yet have a delineation of the types of lesions that progress to tumor malignancy. We studied tissues from primary tumors and secondary lesions, and compared it with the surrounding normal kidney tissue using comparative genomic hybridization to determine their potential for malignancy. Although our sample size was small, we found that small multifocal tumors have the same potential as primary carcinoma to lead to RCC malignancy. Further genetic studies in a larger sample of patients is necessary before the risk of different lesions to remain benign or progress to RCC can be defined absolutely.