Renal cell carcinoma: Biological features and rationale for molecular-targeted therapy

Cancer cells are characterized by indefinite proliferation, invasiveness and metastases. These characteristics are usually related to one another. Namely, cancer cells that proliferate rapidly tend to invade and metastasize. Renal cell carcinoma (RCC) typically does not proliferate rapidly nor does it invade the surrounding tissues, but it does metastasize. RCC has several peculiar characteristics that are not observed in other cancers: a relatively late recurrence, a high frequency of paraneoplastic syndrome, hypervascularity and the spontaneous regression of metastatic lesions after the excision of the primary tumor. These clinical observations suggest that cytokines or growth factors are important contributors to microenvironments favoring the growth of cancer cells. Thus, the blockade of cell-to-cell communication might have some therapeutic potential. Accordingly, a popular strategy for molecular-targeted therapy for RCC targets the vasculization of RCC induced by vascular endothelial growth factor (VEGF). This review highlights the biological features of RCC that are relevant to molecular-targeted therapy.