The normal treatment for Cancer of the Kidney is Radical Nephrectomy or total removal of the kidney.
These days however, most cancers of the kidney are small and hence it is preferable to only remove that part of the kidney that has the cancer rather than the whole kidney. This is called a partial Nephrectomy.
This preserves kidney function which is important. It also has a high cure rate which is just as good as the cure rate when the whole kidney is removed.