Рак почек: типы, факторы риска, симптомы и диагностика.

The main types of kidney cancer are renal cell cancer (RCC), transitional cell cancer (TCC), and Wilms' tumor. RCC makes up approximately 80% of kidney cancers, and TCC accounts for most of the rest. Risk factors for RCC and TCC include smoking, certain pain medications, previous bladder cancer, being overweight, high blood pressure, certain chemicals, and a family history. Onset is usually after the age of 45. For cancers that are confined to the kidney, the five year survival rate is 93%, if it has spread to the surrounding lymph nodes it is 70%, and if it has spread widely, it is 12%. and is responsible for 2% of the world's cancer cases and deaths. The incidence of kidney cancer has continued to increase since 1930. Renal cancer is more commonly found in populations of urban areas than rural areas.

Early on, kidney masses do not typically cause any symptoms and are undetectable on physical examination. As kidney cancer becomes more advanced it classically results in blood in the urine, flank or back pain, and a mass. The classic triad of visible blood in the urine (hematuria), flank pain and palpable abdominal mass occurs in less than 15% of the cases. RCC may present with signs and symptoms caused by the substances the cancer cell produce (i. e. paraneoplastic syndromes). Paraneoplastic syndromes caused by kidney cancer can be broadly classified as endocrine and non endocrine. Endocrine dysfunctions include increase in blood calcium levels (hypercalcemia), high blood pressure (hypertension), increased red bloods (polycythemia), liver dysfunction, milky nipple discharge unrelated normal breast feeding (galactorrhea), and Cushing's syndrome. Non endocrine dysfunctions include deposition of protein in tissue (amyloidosis), decrease in hemoglobin or red blood cells (anemia), disorders of nerves, muscles (neuromyopathies), blood vessels (vasculopathy) and blood clotting mechanisms (coagulopathy).

Factors that increase the risk of kidney cancer include smoking, high blood pressure, obesity, faulty genes, a family history of kidney cancer, having kidney disease that needs dialysis, being infected with hepatitis C, and previous treatment for testicular cancer or cervical cancer. There are also other possible risk factors such as kidney stones being investigated. About 25 30% of kidney cancer is attributed to smoking.

Due to the increase in ultrasound and CT imaging for nonspecific abdominal complaints, kidney masses are frequently incidentally diagnosed on medical imaging. More than 60% of renal cell carcinoma (the most common type of kidney cancer), are diagnosed incidentally by abdominal imaging for nonspecific abdominal complaints. Kidney masses can be classified by the nature of the cells in the growth, or by its appearance on radiography. However, kidney masses can be due to growth of normal tissue (benign), inflammatory (a reaction of the immune system), or vascular (cells of the blood vessels).

People with suspected kidney cancer should also have their kidney function evaluated to help determine treatment options. Blood tests to determine kidney function include a comprehensive metabolic panel (CMP), a complete blood count (CBC).

Staging is the process that helps determine the extent and spread of the disease. Renal cell carcinoma is the only type of kidney cancer that can be staged. The first step of staging follows the TNM staging system proposed by the Union International Contre le Cancer that is widely used among cancers in other organs. Stage TNM DescriptionTx, N0, M0Tumor cannot be assessedT0, N0, M0No evidence of primary tumorIT1, N0, M0Tumor ≤7 cm; limited to kidneyT1a, N0, M0Tumor ≤4 cm; limited to kidneyT1b, N0, M0Tumor 4 ≤7 cm; limited to kidneyIIT2, N0, M0Tumor >7 cm; limited to kidneyT2a, N0, M0Tumor 7 ≤10 cm; limited to kidneyT2b, N0, M0Tumor >10 cm; limited to kidneyIIIT3, N0, M0Tumor extends to major veins or perinephric tissue but not into ipsilateral adrenal gland nor beyond Gerota's fasciaT3a, N0, M0Tumor grossly extends into renal vein or its segmental branches, or tumor invades the pelvicalyceal system, or tumor invades perirenal and/or renal sinus fat but not beyond Gerota's fasciaT3b, N0, M0Tumor grossly extends into vena cava below the diaphragmT3c, N0, M0Tumor grossly extends into vena cava above the diaphragm or invades the wall of the vena cava T1 T3, N1, M0 The main tumor can be any size and may be outside the kidney, but it has not spread beyond Gerota’s fascia. The cancer has spread to regional lymph nodes (N1) but has not spread to distant lymph nodes or other organs (M0). IVT4, any N, M0 Tumor invades beyond Gerota's fascia Any T, any N, M1 Tumor has spread to distant lymph nodes and/or other organs. The lungs are the most common site for metastasis, If the cancer cannot be treated with surgery other techniques such as freezing the tumour or treating it with high temperatures may be used. However, these are not yet used as standard treatments for kidney cancer. Recently, evidence stemming from the KEYNOTE 564 study has shed light on the potential use of systemic therapy in the adjuvant setting, with promising results. Patients exhibiting specific clear cell RCC tumor characteristics and having undergone treatment with Pembrolizumab for 17 cycles (around 1 year) had significant improvement in disease free survival. However, the study has yet to yield conclusive findings in relation to overall survival. Other treatment options include biological therapies such as everolimus, torisel, nexavar, sutent, and axitinib, the use of immunotherapy including interferon and interleukin 2. Immunotherapy is successful in 10 to 15% of people. Sunitinib is the current standard of care in the adjuvant setting along with pazopanib; these treatments are often followed by everolimus, axitinib, and sorafenib. Immune checkpoint inhibitors are also in trials for kidney cancer, and some have gained approval for medical use. In the second line setting, nivolumab demonstrated an overall survival advantage in advanced clear renal cell carcinoma over everolimus in 2015 and was approved by the FDA. Cabozantinib also demonstrated an overall survival benefit over everolimus and was approved by the FDA as a second line treatment in 2016. Lenvatinib in combination with everolimus was approved in 2016 for patients who have had exactly one prior line of angiogenic therapy. In Wilms' tumor, chemotherapy, radiotherapy and surgery are the accepted treatments, depending on the stage of the disease when it is diagnosed.

The United States' NIH estimates for 2013 around 64,770 new cases of kidney cancer and 13,570 deaths from the disease. The incidence of kidney cancer is also increasing in the United States. This is thought to be a real increase, not only due to changes in the way the disease is diagnosed.

The most recent estimates of incidence of kidney cancer suggest that there are 63,300 new cases annually in the EU25. In Europe, kidney cancer accounts for nearly 3% of all cancer cases. Kidney cancer is the eighth most common cancer in the UK (around 10,100 people were diagnosed with the disease in 2011), and it is the fourteenth most common cause of cancer death (around 4,300 people died in 2012).