Micrograph of Renal Cell Carcinoma (RCC). Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport waste molecules from the blood to the urine. RCC is the most common type of kidney cancer in adults, responsible for approximately 90â??95% of cases. Initial treatment is most commonly either partial or complete removal of the affected kidney(s). Where the cancer has not metastasised (spread to other organs) or burrowed deeper into the tissues of the kidney, the 5-year survival rate is 65â??90%, but this is lowered considerably when the cancer has spread.