Renal cell carcinoma

　　The etiology of renal cell carcinoma is still unclear. Ethnicity and geographical conditions are not important factors in causing kidney tumors. It has been reported that aromatic hydrocarbons, aromatic amines, aflatoxins, hormones, radiation, and viruses can cause renal cell carcinoma. Certain genetic diseases such as tuberous sclerosis and multiple neurofibromatosis can be associated with renal cell carcinoma; renal medullary carcinoma associated with renal pelvis carcinoma may be related to local long-term chronic stimulation.

　　Some researchers proposed in 1990 that smoking is related to renal cell carcinoma, with quitters having twice the risk of developing renal cell carcinoma compared to non-smokers, and heavy smokers having a higher incidence than light smokers. The duration of smoking is directly related to the incidence rate. It is believed that the content of various mutagenic substances in the urine of smokers increases; dimethyl nitrosamine in tobacco can cause renal cell carcinoma, although it has not been clinically confirmed, but animal experiments have induced renal cell carcinoma in rabbits, so they believe that smoking habits, combined with other risk factors such as alcoholism, occupational exposure, and others, can further increase the risk of developing renal cell carcinoma. Therefore, prevention is the key to staying away from the disease.

　　Renal cell carcinoma often leads to secondary polycythemia. Renal cell tumors often metastasize to the lungs, bones, liver, and other organs. There are also many extrarenal manifestations that are not related to the urinary system, such as high fever, abnormal liver function, anemia, hypertension, polycythemia, and hypercalcemia, among others. The most serious complication is death.

　　A small number of renal cell carcinomas are associated with increased gonadotropin levels, which can cause breast enlargement, hyperpigmentation of the areola, and decreased libido in males, and hirsutism and amenorrhea in females.

　　1. Patients with renal cell carcinoma may develop secondary amyloidosis, which itself can lead to renal failure. Patients with renal cell carcinoma who develop secondary amyloidosis have poor prognosis. Proteinuria and nephrotic syndrome can also occur in patients with renal cell carcinoma.

　　2. Renal cell carcinoma often leads to metastasis and multiple organ tumors.

　　Medical research indicates that the symptoms of renal cell carcinoma are diverse, ranging from typical triad symptoms such as hematuria, pain, and possibly palpable renal masses, to less obvious peritumoral syndromes, with the triad often appearing in the later stages. Typically, only 10% of patients exhibit typical symptoms, and most are discovered incidentally. The kidneys are located in a concealed position, and when lesions occur, they are often detected through changes in urine, serving as a signal for patients to seek medical attention. Therefore, hematuria is a common symptom of renal cell carcinoma, but before hematuria appears, the clinical manifestations of renal cell carcinoma can vary greatly. Sometimes, the tumor volume is very large, and even signs of metastasis to the lungs, bones, and other organs may appear. It can be asymptomatic, except for the three typical symptoms of hematuria, lumbar pain, and masses. Renal cell carcinoma also has many extrarenal manifestations that are not related to the urinary system, such as fever, abnormal liver function, anemia, hypertension, polycythemia, and hypercalcemia, among others.

　　1.Hematuria: Gross hematuria or microscopic hematuria is the most common symptom, and most cases show that the tumor invades the renal pelvis and renal calyces, causing intermittent attacks, often without pain. Clinically, it is often called intermittent, painless gross hematuria, which is a characteristic symptom of urinary system tumors. However, when the blood clot passes through the ureter, it can cause colic.

　　2.Back Pain: Most are dull pain and discomfort, localized in the lumbar or back area, because as the tumor grows, the tension of the renal capsule increases. If the tumor invades the surrounding tissues of the kidney, it can also cause pain, resulting in persistent pain, indicating that the tumor has invaded the nerves and lumbar vertebrae. Hematuria can solidify into string-like blood clots in the ureter, excreted through urine, which can cause renal colic.

　　3.Mass: 10% of renal cell carcinoma patients can feel a mass in the lumbar and upper abdominal area, which may be the only sign. The mass is hard, with uneven or nodular surface. In emaciated patients and when the tumor is located at the lower pole, the mass can be palpated during physical examination. If the mass is fixed, it indicates infiltration around the kidney, with poor prognosis. The triad of hematuria, back pain, and mass is not common. If they occur simultaneously, it is often a sign of advanced tumor. Lateral abdominal pain (abdominal pain), mass is common in children and more common than in adults; tumors located at the lower pole of the kidney are easy to touch, and the mass is solid, painless, and moves with respiration.

　　4.Varicocele; When the renal tumor invades the renal vein or compresses the internal spermatic vein, it often occurs on the left side. When the inferior vena cava is invaded, it can be accompanied by lower limb edema.

　　5.Systemic Symptoms: Fever is one of the common extrarenal manifestations of renal cell carcinoma, with low fever or high fever. Below 38℃ accounts for about 45%, above 38℃ accounts for about 7%, and a few can reach above 39℃. The rise in body temperature is likely related to the pyrogen produced by the renal cell carcinoma tissue, and there is no direct relationship with the necrosis and hemorrhage of the tumor. After the resection of renal cell carcinoma, the body temperature returns to normal. 2% to 3% of renal cell carcinoma patients are clinically manifested only by fever. Therefore, for middle-aged and elderly patients with unexplained fever, the possibility of renal cell carcinoma should be considered so that relevant examinations can be carried out.

　　Regarding the prevention of renal cell carcinoma, it can be roughly divided into the following points:

　　1.Primary PreventionAbstain from smoking and drinking, establish a good living habit, and engage in regular and moderate physical exercise. For personnel exposed to cadmium industrial environments, strict protection should be carried out.

　　2. Second-level prevention:Mass screening is one of the methods for early detection of renal tumors, using simple B-ultrasound renal examination methods; further examination should be performed for those with rapid erythrocyte sedimentation rate, high blood calcium, and anemia. The complaints and clinical manifestations of renal cell carcinoma patients are variable, the renal position is hidden, and it is difficult for early self-diagnosis and self-examination. Hematuria is the most common symptom of renal tumors, often painless, intermittent, and gross hematuria. Pay attention that in the elderly, hematuria is often considered to be caused by benign prostatic hyperplasia and stones, and the possibility of renal cell carcinoma should be警惕. Only 10% of renal tumors have symptoms of back pain and masses, and it should be vigilant for extrarenal manifestations such as fever, hypertension, hypercalcemia, increased erythrocyte sedimentation rate, anemia, abnormal liver function, weight loss, polycythemia, and varicocele on the left testicle that does not disappear when lying flat. Renal cell carcinoma should be treated as soon as possible after discovery, and surgery should be performed to remove the tumor. Radical nephrectomy includes the removal of perirenal fascia fat, adrenal glands, lymphatic tissue, and middle and upper ureter. The renal vein and inferior vena cava thrombi should be removed. Chemotherapy and radiotherapy are not very effective for renal cell carcinoma, and immunotherapy has some efficacy.

　　3. Third-level prevention: Patients in the late stage may develop cachexia, local pain, and severe anemia due to bleeding within the tumor. Supportive therapy, such as blood transfusion, intravenous hyperalimentation, palliative nephrectomy, or selective regional arterial chemotherapy with embolization treatment, can be used for severe bleeding, pain, and extratumoral symptoms, such as compression of surrounding organs. Symptomatic treatment such as analgesics can reduce the pain and prolong the life of patients.

　　Medicine shows: The general examination of renal cell carcinoma usually includes the following points.

　　One: General examination

　　Hematuria is an important symptom, and polycythemia can occur in 3% to 4%; progressive anemia can also occur. In cases of bilateral renal tumors, the total renal function usually does not change, and the erythrocyte sedimentation rate increases. Some patients with renal cell carcinoma may not have bone metastasis, but may have symptoms of hypercalcemia and increased serum calcium levels. Symptoms can be quickly relieved and blood calcium levels can return to normal after the removal of the renal tumor. Sometimes it can develop into liver dysfunction, and if the tumor kidney is removed, it can be restored to normal.

　　Two: X-ray angiography is the main method for diagnosing renal cell carcinoma.

　　(1) X-ray film: X-ray film can show an enlargement of the renal outline, changes in the contour, and occasionally calcification of the tumor, which can be localized or extensive fluffy shadows within the tumor, or can become calcified lines, shell-like, especially common in young people with renal cell carcinoma.

　　(2) Intravenous urography is a routine examination method. Due to the inability to show tumors that have not caused deformation of the renal pelvis and calyces, and the difficulty in distinguishing whether the tumor is renal cell carcinoma, the importance of intravenous urography has decreased. Renal angiomyolipoma, renal cysts, so it is necessary to perform ultrasonography or CT scan for further differentiation. However, intravenous urography can understand the function of both kidneys and the condition of the renal pelvis, calyces, ureters, and bladder, which is of important reference value for diagnosis.

　　(3) Renal arteriography: Renal arteriography can detect tumors that have not changed in the urinary system造影, renal cancer shows new blood vessels, arteriovenous fistula, and contrast agent pooling (Pooling) increased encapsulating blood vessels. Vascular造影 varies greatly, and sometimes renal cancer may not be visible, such as tumor necrosis, cystic change, arterial embolism, etc. In larger renal cancers, selective renal arteriography can also be followed by renal arteriography, which can reduce bleeding during surgery. Renal cancer that cannot be surgically removed and has severe bleeding can be treated by renal arteriography as palliative therapy.

　　3. Ultrasound scan

　　Ultrasound examination is the simplest and non-invasive examination method, which can be part of routine physical examination. Renal tumors larger than 1cm can be detected by ultrasound, and it is important to distinguish whether the mass is renal cancer. Renal cancer is a solid mass, and due to possible internal bleeding, necrosis, and cystic change, the echo is uneven, usually low echo, and the境界 is not very clear, which is different from renal cysts. Renal space-occupying lesions may cause deformation or breakage of renal pelvis, calyces, and renal sinus fat. Renal papillary cystadenocarcinoma has a similar ultrasound appearance to cysts and may have calcification. When it is difficult to distinguish between renal cancer and cysts, puncture can be performed, and puncture under ultrasound guidance is relatively safe. The puncture fluid can be used for cytological examination and cyst造影. The cyst fluid is often clear, without tumor cells, and low in fat. During造影, a smooth cyst wall can be confirmed as benign lesions.

　　4. CT scan

　　CT plays an important role in the diagnosis of renal cancer, and can discover renal cancer that has not caused changes in renal pelvis and calyces and has no symptoms, and can accurately measure tumor density, and can be performed in outpatients, and CT can accurately stage the disease.

　　Patients with renal cell cancer should pay attention to the following points in diet:

　　1. Avoid: fishy and spicy foods, fried and fried foods, crabs, garlic, scallions, coriander, dog meat, alcohol, beef, mutton, coffee, five-spice powder, and all kinds of irritants.

　　2. Those with severe edema and hypertension should avoid salt, limit the intake of protein-rich foods, and drink less water. If there is no edema, there is no limit to the intake of water and protein-rich foods.

　　3. For those with microscopic hematuria and those prone to heat, they should drink more water, eat more apples, white sugar, black sesame, fungus, and other yin cooling foods.

　　4. For patients with nephrotic syndrome and other kidney diseases with large amounts of proteinuria, limited food intake and high-quality protein can be consumed. For example, milk, crucian carp, and adults should consume about 60g per day, and mainly high biological protein.

　　5. Diet for renal insufficiency.

　　Refined diet: In addition to the principle of low protein diet, more starch should be eaten to ensure sufficient calories, and the intake of water and salt should be determined according to the condition of edema.

　　Five low and one high diet: low salt, low fat, low protein, low phosphorus, low potassium, high vitamins.

　　The following foods should be avoided: egg whites, animal internal organs, millet, edible mushrooms, seaweed, soy products, tea, tangerines, walnuts, peanuts, bananas, etc. It is strictly forbidden to use vegetable oil.

　　General treatment methods of Western medicine include:

　　One, surgical treatment

　　Surgical treatment of renal cell carcinoma is divided into simple nephrectomy and radical nephrectomy. Currently, it is universally recognized that radical nephrectomy can improve survival rates. Radical nephrectomy includes the perirenal fascia and its contents: perirenal fat, kidney, and adrenal glands. There is still controversy about whether to perform local lymph node dissection in radical nephrectomy. Some believe that lymph node metastasis often has hematogenous metastasis, and cases with lymphatic metastasis eventually all have hematogenous metastasis. Lymph nodes are widely distributed and difficult to remove cleanly. However, some also believe that lymph node metastasis is mainly around the renal hilum; inferior vena cava and aortic region, which can be resected radically. But for those with metastatic foci found in radical lymph node dissection surgery, very few survive for more than 5 years. It is necessary to ligate the renal artery and renal vein first during renal cell carcinoma surgery.

　　Two, immunotherapy

　　For many years, it has been proven that lymphocytes in human solid tumors have an immune response to their own tumor cells, but the cytotoxic effect of tumor infiltrating lymphocytes (TIL) on autologous tumor cells is often low due to inhibitory mechanisms within the tumor. These TIL cells need to be stimulated and expanded in vitro to fully exert their cytotoxic effect on autologous tumors. The culture of normal human lymphocytes and interleukin-2 (IL-2) can produce effector cells known as lymphokine-activated killer cells, i.e., LAK cells. A group of 57 cases of renal cell carcinoma were treated with LAK cells and IL-2; 36 cases with LAK cells + IL-2, 21 cases with IL-2 alone, 4 cases in the LAK cells + IL-2 group achieved complete remission (CR), 8 cases achieved partial remission (PR), and the efficacy rate was 12/36 (33%). In the IL-2 group, only 1/21 cases achieved CR.

　　Three, chemotherapy

　　The chemotherapy effect of renal cell carcinoma is not good, and the effect of single drug treatment is even worse. Some experts have calculated that among 37 chemotherapy drugs, alkylating agents have a better effect on the treatment of renal cell carcinoma.

　　Four, combined immunotherapy and chemotherapy

　　A group of 957 patients with renal cell carcinoma metastasis ± recurrence treated with interferon alpha-2A, with an efficacy rate of 12% when used alone.