Do doctors usually remove the entire kidney with a wilms tumor?

Depends: This was studied in 2003; only if the tumor is very small and after a good response to chemotherapy, or if the tumor is bilateral or likely to be bilateral, or there isn't a second kidney should a partial nephrectomy (not taking the whole kidney) even be considered. Remember that this is a vicious cancer.

Usually: If only one kidney is affected and the other is clearly normal, most of the time the entire kidney is removed along with the tumor. In the rare case where the tumor involves both kidneys, chemotherapy is given followed by an attempt to remove the tumors while keeping as much normal kidney tissue as possible.