Gia,
Removing the primary tumor in the kidney has a aurvival advantage. Most often, the kidney tumor is taken out first, but if the tumor is large or near a vital structure, systemic treatment such as Nexavar may be tried first so that surgery may be less extensive. Very, very rarely, mets can disappear after the primary kidney tumor is removed, but I wouldn't forgo further treatment because the chances are small.
Radiofrequency ablation (RFA) is an effective way to destroy a small primary kidney tumor. You should be sure that a biopsy is taken so you know what kind of kidney cancer it is in case the kidney cancer has spread, for the type of treatment will depend on the type of kidney cancer. Cryo (freezing the tumor) is another possibility, but again, you need to be sure that the tumor is biopsied. Both seem to be pretty effective, but if you have surgery, you know for sure that the primary tumor is gone. Sometimes, the RFA or cryo has to be repeated because not all tumor cells are killed.
Nexavar is a new drug. It has prolonged life in trials, but more time is necessary to find out how effective it is in the long run.