In the past, it was thought that the standard treatment for kidney cancer was to remove the entire kidney, regardless of whether the tumor was large or small, which we called radical surgery. Over time, with more research, urologists discovered that: in fact, for some small tumors, say 4cm or less (some scholars believe 7cm or less), treatment does not necessarily require removal of the entire kidney, but removal of the tumor and a small amount of kidney tissue surrounding the tumor is sufficient. It is found that for such small kidney tumors, kidney-conserving surgery can completely achieve the same tumor control effect as radical surgery. Data from the Center for Cancer Control of Sun Yat-sen University show that for stage I (confined to the kidney, tumor diameter below 7 cm) kidney cancer, there is no difference in kidney cancer-specific survival rate after kidney preservation surgery and radical surgery. However, the advantage of kidney-conserving surgery is that patients still have two kidneys after surgery, and the decline in kidney function after surgery is much less than after radical surgery. data from Cleveland Clinic show that overall kidney function declines by about 9.6% after kidney-conserving surgery, compared to 32.2% after radical surgery. The average age of onset of kidney cancer is about 65 years old, an age when serious kidney function-threatening diseases such as hypertension and diabetes also develop, so clearly better kidney function is more beneficial to the long-term survival of patients. Nowadays, a number of studies have found that for small kidney cancer, the overall survival rate of patients after kidney-preserving surgery is rather higher than those after radical surgery. Since kidney-conserving surgery has such advantages, should all patients with kidney cancer choose kidney-conserving surgery to treat kidney cancer? The answer is in the negative. Whether kidney-conserving surgery can be performed depends mainly on the location and size of the tumor as well as the distance from the renal hilar vessels. Of course, it is also related to the patient’s physical condition, willingness and understanding of the risks of surgery. Some tumors are large in size, but the tumor protrudes from the surface of the kidney and is far away from the renal vessels, so kidney preservation surgery can be performed; however, some tumors are small in size, but they are close to the important blood vessels of the kidney, so kidney preservation surgery may not be successful. It is important to note that even if the kidney-conserving surgery is performed successfully and no complications occur during the surgery, postoperative complications may still occur. The major postoperative ones include bleeding and urinary leakage, which have a 3% and 7% chance of occurrence, respectively.