Medical expert of the article
New publications
What causes kidney cancer?
Last reviewed: 04.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Causes of kidney cancer
The cause of kidney cancer is unknown. Several groups of risk factors have been identified that contribute to the development of this neoplasm, including smoking, obesity, arterial hypertension, use of diuretic drugs, terminal stage of chronic renal failure, and diabetes mellitus.
[ Pathogenesis of kidney cancer
Kidney cancer tends to locally destructive growth with invasion of venous vessels and formation of tumor thrombosis of the renal, inferior vena cava and right heart chambers (10% of cases). Dissemination of the tumor process occurs through lymphogenous and hematogenous routes. Most often, the lungs are affected (32%), bones (25%), regional (retroperitoneal) lymph nodes (20%) and liver (7.5%). Metastasis to non-regional groups of lymph nodes, adrenal glands, contralateral kidney, brain, soft tissues is also possible.
Classification of kidney cancer
TNM classification Union International Cancer Control (UICC), 2002
Category T.
- Tx - the primary tumor cannot be assessed.
- T0 - undetected primary tumor.
- T1 - tumor less than 7 cm in diameter in greatest dimension, limited to the kidney.
- T1a - tumor with a diameter less than or equal to 4 cm in greatest dimension, limited to the kidney.
- T1b - tumor greater than 4 cm and less than 7 cm in greatest dimension, limited to the kidney.
- T2 - tumor with a diameter greater than or equal to 7 cm in greatest dimension, confined to the kidney.
- T3 - locally advanced process with invasion of large venous vessels, ipsilateral adrenal gland or pararenal tissue, without invasion of Gerota's fascia.
- T3a - the tumor grows into the tissue of the ipsilateral adrenal gland or pararenal tissue (including peripelvic tissue), without invasion of Gerota's fascia.
- T3b tumor thrombosis of the ipsilateral renal vein, its branches (including muscular branches), or the inferior vena cava, not reaching the level of the diaphragm.
- T3c - tumor thrombosis of the inferior vena cava with possible invasion into its wall above the level of the diaphragm.
- T4 - the tumor invades Gerota's fascia.
Category N - Regional lymph nodes.
- Nx - regional lymph nodes cannot be assessed.
- N0 - unaffected regional lymph nodes (the basis is the absence of signs of malignant growth in more than 8 removed lymph nodes; when removing a smaller number of collectors, the presence of tumor cells in the removed preparation plays a decisive role).
- N1 - solitary metastasis in a regional lymph node.
- N2 - metastatic involvement of more than one regional lymph node.
Category M.
- Mx - the presence of distant metastases cannot be assessed.
- M0 - absence of distant metastases.
- Ml - presence of distant metastases.
Morphological classification of kidney cancer
There are 5 types of kidney cancer:
- clear cell (60-85%);
- chromophilic, or papillary (7-14%);
- chromophobic (4-10%);
- oncocytic (2-5%);
- collecting duct cancer (1-2%).
Histological types of kidney cancer have different clinical courses and are characterized by different responses to systemic therapy.