Renal cell carcinoma (RCC, aka hypernephroma) is the most common form of kidney cancer arising from the proximal renal tubule. It is the most common type of kidney cancer in adults. Initial treatment is most commonly a radical or partial nephrectomy. Where the tumour is confined to the renal parenchyma, the 5-year survival rate is 60-70%, but this is lowered considerably where metastases have spread. It is resistant to radiation therapy and chemotherapy, although some cases respond to immunotherapy. Targeted cancer therapies such as sunitinib have improved the outlook for RCC, although they have not yet demonstrated improved survival.