How to detect kidney cancer in early stage 1. Hematuria: Painless intermittent hematuria is a major feature of kidney tumor. Painlessness means that the tumor does not have any pain except hematuria in the early stage; intermittent means that hematuria appears when the tumor bleeds or invades the renal pelvis, and then disappears when the bleeding stops. This early symptom of kidney tumor is very deceptive. Many patients or their family members are paralyzed and careless because they see that the patient is not in pain and sometimes good and sometimes bad, which results in regrets when it is delayed to the late stage and cannot be treated. Zhang Sheng, Department of Medical Oncology, Cancer Hospital of Fudan University 2. Swelling: hard and uneven swelling is felt in the waist or abdomen. It indicates that the kidney tumor is already large in size. Some children aged 1~3 years old may also have renal embryonic masses, which are often found by mothers. 3.Pain: Patients with kidney cancer often have dull pain or hidden pain in the abdomen; renal pelvic tumor only shows renal colic when it causes hydronephrosis or hematuria; renal embryonal tumor usually does not cause pain. 4. Systemic poisoning symptoms: Some patients first show systemic poisoning symptoms, such as wasting, anemia and weakness. There are 10-20% of patients have different degrees of fever. Hypothermia is commonly seen in renal embryonal tumors. Kidney tumors are not rare. According to statistics, kidney tumors account for about 0.47~0.66% of systemic tumors in China and about 3% in foreign countries. Most of the kidney tumors are malignant, mainly including renal cancer, renal pelvis tumor and renal embryonal tumor. Due to the hidden location of kidney, kidney tumors are mostly without obvious symptoms in the early stage, therefore, people must pay attention to the traces that appear in order to strive to get timely treatment.