Surgical removal of an entire kidney (radical nephrectomy) was once the standard of care for all patients with kidney tumors. But research has shown that this approach is unnecessary and even harmful for some people with small or slow-growing kidney tumors that are not immediately life threatening. Urologic surgeon Paul Russo pioneered the development of kidney-sparing surgical procedures that preserve kidney function. Doctors at Memorial Sloan-Kettering Cancer Center also use minimally invasive laparoscopic and robotic techniques that can reduce side effects. In some cases, a treatment called active surveillance may be appropriate, in which tumors are monitored closely and more-intensive treatment is deferred.