This research is being done because there is no effective therapy to prevent recurrence of kidney cancer.

Sunitinib and sorafenib are drugs which have been approved by the FDA for use in advanced kidney cancer, but not in the setting of kidney cancer which has been completely removed. The purpose of this study is to determine if either drug can prevent recurrence of kidney cancer and to compare the effects (both good and bad) of sunitinib and sorafenib with placebo on patients and their kidney cancer to see which is better. It is not known whether the benefits of taking either sunitinib or sorafenib will outweigh the risks.