If a tumor is found in the kidney, does it have to be cancer? Kidney tumors are divided into two categories: benign and malignant tumors. Although most data show that malignant tumors in kidney account for 96-98% of all kidney tumors, and cancer is the main one, some patients still suffer from benign tumors such as renal adenoma, renal cyst, renal hemangioma, renal malignant tumor, renal lipoma, etc. Some benign tumors are difficult to be distinguished from malignant tumors and need to be treated by experienced oncologists. Why many kidney tumor patients have no symptoms? Because the kidney is located deep in the human body and surrounded by other organs than the abdomen, so early kidney tumors are not easy to show symptoms and be ignored. In recent years, with the development of medical technology and the improvement of people’s health awareness, more and more patients have discovered smaller and early kidney tumors by chance due to health check-ups or going for body check-ups because of other systemic diseases. Therefore, it is correct that all adults should have annual health checkups using inexpensive and non-invasive renal ultrasound that can detect tumors of 1 cm and above in diameter. Good health awareness can lead to disease detection, early diagnosis and early treatment. Why do tumors grow in the human kidney? So far, the cause of kidney cancer is still unclear and may be related to many factors, genetic factors may be one of them. Investigation found that kidney cancer has a tendency to run in families, for example, both brothers suffer from kidney cancer, or three or even five people in a family suffer from kidney cancer. Some hereditary diseases such as tuberous sclerosis and multiple neurofibromas can be combined with renal cell carcinoma; there is familial renal cancer with retinal hemangioma, which can be multifocal cancer or intracapsular cancer, and mutation of VHL gene is also one of the reasons for the development of renal cancer. Meanwhile, the prevalence rate of smokers is significantly higher than that of nonsmokers. There is no definite answer to the relationship between kidney cancer and industrial carcinogens, but male smokers who are frequently exposed to cadmium industrial environment have a higher incidence of kidney cancer than the norm. In addition, there are some reports that certain industrial substances, aflatoxin, hormones, radiation, and contrast agents may cause kidney cancer, and that coffee may increase the risk of kidney cancer in women, and the risk is not related to the amount of coffee. What is a malignant tumor? Renal malformation tumor is a benign tumor, also known as smooth muscle angiomyolipoma because it is composed of blood vessels, smooth muscle and fat. Larger tumors may distort and displace the renal calyces in one or more places, affecting urinary drainage, which may cause damage to kidney function. In addition, because the tumor tissue is rich in blood vessels, it is prone to bleeding. Intratumor bleeding may trigger severe pain and rupture toward the renal pelvis and calyces, which can cause massive hematuria and endanger life. In some cases, the morphological manifestations of malformation tumors are very similar to those of kidney cancer, so it is not easy to distinguish them. The above cases require surgical investigation. What are the main symptoms of kidney cancer? Patients with kidney cancer have variable complaints and clinical manifestations, which can be easily misdiagnosed as other diseases. For many years, hematuria, pain and lumps are called the “triad signs” of kidney cancer, but due to the hidden location of kidney, most of the early stage kidney cancer is asymptomatic. Hematuria: Hematuria is often painless and intermittent, and the whole process of hematuria is visible to the naked eye, and the intermittent period is shortened with the development of lesion. When kidney cancer bleeds a lot, it may be accompanied by renal colic, which is often caused by the passage of blood clots through ureter. The blood clots in hematuria of kidney cancer may be formed in strips by passing through the ureter. The degree of hematuria is not related to the size of the kidney cancer. Sometimes, kidney cancer may manifest as persistent microscopic hematuria. 2.Lower back pain: lower back pain is another common symptom of kidney cancer, mostly dull pain, which is confined to the lower back. The pain is often caused by the growth of the mass and swelling of the renal peritoneum. When the tumor invades the surrounding organs and lumbar muscle, the pain is more severe and persistent. 3.Lumps: Lumps are also a common symptom. About 1/3 to 1/4 of kidney cancer patients can find enlarged kidney when they visit the doctor. Since the kidney is hidden, it is difficult to detect the mass until the kidney cancer reaches a large size. Generally, it is already an advanced symptom when a lump is felt in the abdomen. Pain: Pain is seen in about 50% of cases and is also a late symptom, which is caused by the persistent pain in the affected lumbar area due to the tumor’s invasion and compression of connective tissue, muscle, lumbar vertebrae or lumbar nerve in the posterior abdominal wall. 5.Extra-renal manifestations of kidney cancer: unexplained fever, or metastasis when first detected, lung symptoms such as weakness, weight loss, loss of appetite, anemia, cough and coughing up blood. In addition, the effects of renal adenocarcinoma are caused by the endocrine activity of the tumor and include erythrocytosis, hypertension, hypotension, hypercalcemia, and febrile syndrome. These systemic, neutrophilic and endocrine effects are non-specific and 30% of patients can present with multiple mixed presentations, which are valuable tumor clues. Why the earlier kidney cancer is detected, the better? The earlier kidney cancer patients are treated, the greater their survival benefit. Statistically, the survival rate of renal cell carcinoma is 60% for overall 5-year survival, 90~100% for stage I, 65~75% for stage II, 40~70% for stage III, and 10~20% for stage IV. Survival rates for patients with renal cell carcinoma have improved over the last 30 years, thanks in large part to the availability of ultrasound and CT scans, leading to an increase in incidental renal cell carcinoma and more patients being detected and treated early. What are the main treatments after kidney cancer? Treatment of kidney cancer is based on the stage of the cancer and the overall physical condition of the patient. Once the stage of the tumor is confirmed, one or several treatments can be considered, either alone or in combination: Surgery: radical nephrectomy, partial nephrectomy, and so resting nephrectomy for kidney cancer, all of which can be laparoscopic surgery or open surgery after judging according to the stage. Metastatic foci resection. Immunotherapy. Molecular targeted therapy. Radiotherapy, cryoablation and radiofrequency ablation treatment, etc. What should I do if I have kidney cancer? First of all, you should see a specialist to clarify the nature of the tumor and the current level of invasion, that is, to see how far the tumor has progressed. If the tumor is confined to the kidney and is highly suspected to be malignant, surgery should be performed as soon as possible, and whether the surgery is thorough or not is the most important for the treatment effect and prognosis of such patients. If it is kidney cancer, it is usually treated by radical nephrectomy. Up to now, radical resection is the most effective treatment for early stage I and II kidney cancer confined within the kidney, as well as stage III locally progressive tumors. If the kidney cancer is less than 4 cm in diameter and located on the surface or one pole of the kidney, only part of the kidney including the side of the tumor can be removed while preserving the remaining normal kidney tissues to achieve the same radical treatment effect. How is the standard radical kidney cancer surgery performed? The standard radical kidney cancer surgery should remove all tissues including all kidneys, adrenal glands, perinephric fat capsule, upper ureter with or without lymph node dissection outside the perinephric fascia (Gerota’s fascia). If the tumor is small, can I remove only the tumor and keep some kidneys? If the tumor is small, usually less than 4 cm, and the tumor is protruding from the surface of the kidney, you can choose to remove only the tumor and the normal kidney tissue around the tumor, while preserving most of the normal kidney tissue. This surgery is called “kidney unit preserving nephrectomy”. It is also commonly used in cases of bilateral kidney cancer or isolated kidney cancer, as well as in cases of poor renal function such as renal vascular hypertension, kidney stones, renal tuberculosis, and ureteral stenosis of the renal pelvis. If a tumor-grown kidney is removed, will it be life-threatening due to kidney failure? No, it will not. Because a person normally has two kidneys, and each kidney has 2 million kidney units. And only 1 million normal kidney units are needed to maintain a normal life of an adult, which is 1/2 kidney tissue. Therefore, in most cases, only one normal kidney can still live a normal life without kidney failure, but we should pay more attention and protect kidney function in general. What are the advantages of laparoscopic surgery in kidney cancer treatment? For early stage kidney cancer, laparoscopic surgery has been considered as the preferred method of radical kidney cancer treatment, which has the same treatment effect compared with open radical kidney cancer treatment, but laparoscopic surgery has more obvious advantages of less trauma, less bleeding, less postoperative pain, faster recovery and shorter hospitalization time. Why do you say that both radiotherapy and chemotherapy have little effect on kidney cancer? Because, renal cell carcinoma is highly resistant to chemotherapy, therefore, chemotherapy is generally not recommended to treat patients with advanced kidney cancer. Gemcitabine in combination with 5-FU has some effect, but the remission rate is not better than treatment with interleukin-2 or interferon. Radiation therapy has no important role in the treatment of kidney cancer yet. Most scholars do not advocate radiation therapy for kidney cancer, and it can only be used as adjuvant treatment before and after surgery. For those with rapid tumor growth and obvious toxic symptoms in the short term, preoperative radiotherapy can reduce the tumor volume, decrease the spread of cancer cells during surgery and facilitate surgical operation. For stage II or III kidney cancer or cases where the lesion has spread to adjacent organs or tumor resection is incomplete, postoperative radiotherapy can reduce local recurrence. Meanwhile, for advanced kidney cancer that cannot be removed surgically, radiotherapy can reduce local pain, hematuria and relieve toxic symptoms of bone metastasis. What are the main drug treatments for advanced kidney cancer at present? What is the efficacy? At present, the main therapeutic drugs for advanced kidney cancer are cytokine therapy drugs, such as interferon alpha (IFNα) and interleukin 2 (IL-2); chemotherapy and new targeted drug therapy (such as sorafenib, sunitinib, etc.). Among them, the effectiveness and safety of IFNα treatment for kidney cancer have been studied in a large number of experiments, with an overall effective rate of 8%-15%. The new targeted drugs, sorafenib and sunitinib, have been shown to significantly prolong the median progression-free time in patients with advanced kidney cancer. In 70-80% of these patients, the tumor can be controlled or shrunk. They have replaced immunotherapy as the treatment of choice for advanced kidney cancer.