kidney cancer

Kidney cancer: description

Kidney cancer develops when individual kidney cells malignantly change (degenerate) and begin to proliferate unchecked. The cancerous tumor can develop from different cell types. In about 95 percent of the cases it is a Renal cell carcinoma (Renal carcinoma, adenocarcinoma of the kidney) – a malignant kidney tumor, which usually comes from the cells of the urinary canals (Tubulussystem). There are several types of renal cell carcinoma: the most common is the so-called clear cell carcinoma; other forms include the papillary carcinoma and the ductus Bellini carcinoma. The latter is particularly aggressive and spreads quickly, but is rare.

In many cases, renal carcinoma is located at the lower pole of the kidney and points towards the pelvis. A bilateral involvement of the left and right kidneys at the same time is very rare.

In addition to renal cell carcinoma, other malignant kidney tumors fall into the term kidney cancer. This includes, for example Renal pelvis carcinomawhich is much rarer than renal cell carcinoma. Renal pelvic carcinoma develops from the tissue of the urinary tract, which arise from the kidneys. However, it can trigger symptoms similar to kidney cancer.

In some cases, a malignant kidney tumor turns out to be a secondary tumor (metastasis) of another type of cancer somewhere in the body, such as lung or breast cancer.

Why a kidney tumor is so dangerous

The kidneys are among the organs that are best supplied with blood. As a result, proliferating cancer cells spread very quickly through the blood and lymph vessels in the rest of the organism and form secondary tumors. Such renal cancer metastases occur mainly in the lungs, liver, brain and bones. As soon as the first metastases have formed, prognosis and chances of treatment worsen for patients with a malignant renal tumor.

facts and figures

Renal cancer represents a very rare form of cancer, accounting for about two percent of all malignancies. In 2010, about 14,500 people in Germany became ill with kidney cancer, with the German cancer registry classifying all malignant diseases of the kidney, renal pelvis and ureter as “kidney cancer”. For 2014, experts predict an increase in new cases to 15,500 patients: 9,500 of them male and 6,000 female.

The risk of developing malignant kidney tumors increases with age: young people rarely develop kidney cancer. The average age at diagnosis is 71 years for women and 68 years for men.

Kidney cancer: symptoms

Read all about the typical signs of kidney cancer in the article Kidney Cancer – Symptoms.

Kidney cancer: causes and risk factors

The causes of a tumor on the kidney are still largely unknown. However, there are several risk factors that favor the onset of kidney cancer. This includes acquired risk factors as:

• Smoke
• overweight
• High-fat, low-fiber diet
• Too low fluid intake
• Increased alcohol consumption
• high blood pressure
• Chronic kidney weakness
• Acquired cystic kidney disease
• Abuse of painkillers

Increasing age also increases the risk of kidney cancer. Life expectancy and prognosis then depend mostly on possible comorbidities.

Also hereditary factors can contribute to the development of kidney cancer. A genetic predisposition is suspected in about one in 100 people affected. Some rare hereditary diseases such as tuberous sclerosis and von Hippel-Lindau disease are also associated with an increased risk of kidney cancer.

So far it is not clear whether people who regularly determined chemicals Asbestos, cadmium or lead are exposed to an increased risk of disease.

Kidney cancer: examinations and diagnosis

In most cases, the kidney tumor is accidentally discovered during other examinations – for example during an ultrasound examination. In other cases, it is already tumor-related symptoms that cause a patient to go to the doctor. In order to get to the root of the symptoms, the doctor will usually ask for the medical history first (anamnese). He inquires, among other things, exactly the nature and extent of the complaints.

The next step is the physical examination, The first indications of kidney cancer may be a palpable resistance in the abdominal area, enlarged lymph nodes in the neck and neck area and conspicuous water retention (edema) in the legs. In men, in addition, a newly occurring varicose vein in the testes may be an indication of kidney cancer.

All of these signs can also be symptoms of other illnesses. In order to clarify whether renal cancer is actually present, further investigations are needed. Some of these provide other information that is important for therapy planning (such as size and location of the tumor, presence of metastases):

laboratory tests can confirm the suspicion of kidney cancer: urine and blood samples of the patient are examined for specific changes, such as altered renal function values ​​in the blood or blood in the urine (hematuria).

A clear diagnosis is in the vast majority of cases using a ultrasound (Sonography) possible. Also one Computed tomography (CT) can confirm the suspicion of kidney cancer. An iodine-containing X-ray contrast medium must usually be taken. If the patient does not tolerate this, may alternatively Magnetic Resonance Imaging (MRI) be performed. It can also effectively detect kidney cancer. With such imaging methods, the size and location of the tumor can also be accurately determined. Metastases (in the bones, for example) can also be detected. In addition, bone metastases can also by means of Skeletal scintigraphy be detected.

In rare cases, it may be necessary to determine the vascular supply of the tumor before surgery. This will be a angiography performed an X-ray examination of the vessels using an X-ray contrast agent.

Sometimes, a fine needle also becomes one Tissue sample (biopsy) taken from the kidney tumor in order to examine it more closely in the laboratory. This allows the doctor to determine which type of tissue the tumor has developed from. This can be important for therapy planning.

In individual cases, further investigations may be useful.

Kidney cancer: treatment

The treatment of kidney cancer depends primarily on the tumor stage. There is only one treatment that can really bring healing – the surgical removal of the tumor, This is usually no problem with small tumors. Therefore, it is important that kidney cancer is diagnosed early.

In some cases, the entire kidney – sometimes even the adrenals – must be removed. Wherever possible, however, a “kidney-friendly operation” is performed. This means that the surgeon tries to get as much healthy tissue as possible during the operation.

Even with a larger tumor or if metastases have already spread in the body, surgery makes sense. Although it does not promise a complete cure, it relieves the pain (palliative therapy) and increases the chances of success of further therapeutic measures. Such an operation is often followed by other therapies:

As part of the targeted drug therapy The kidney cancer patients are administered drugs that specifically alter or block the metabolism of tumor cells. In this way, they prevent the renal carcinoma from continuing to grow – the life expectancy of the person affected increases. Well-known active substances are, for example, sunitinib, sorafenib, pazopanib, temsirolism and bevacizumab. Sometimes several such drugs are combined to increase the chances of success of the therapy.

Another treatment option for advanced kidney cancer is the immunotherapy, With active ingredients such as interferon alpha or interleukin-2, the immune system is stimulated to recognize, attack and eliminate well-stained cancer cells. Even so, it can be prevented that the kidney tumor continues to grow. Immunotherapy is only successful in some cases.

Another form of immunotherapy that researchers are still working on uses the patient’s own body cells to stimulate the immune system against kidney cancer – certain white blood cells called dendritic cells. They play an important role in the body’s defense, by presenting prominent parts of, for example, cancer cells on their surface, thus signaling to the defense cells against which “enemy” they must act. Researchers want to take advantage of this mechanism in the treatment of kidney cancer (and other cancers): they load patients’ dendritic cells with typical proteins from cancer cells and inject them under the skin of the patient. Once inside the body, the “vaccinated” cells stimulate the immune system to attack kidney cancer.

A radiotherapy can be used if kidney cancer has already led to secondary tumors (metastases). Above all, it should alleviate the patient’s complaints; a cure is not possible – the renal cell carcinoma (the most common type of kidney cancer) is not sensitive to radiation.

Unlike other cancers, the chemotherapy barely successful in kidney cancer.

In some cases of kidney cancer – for example, if surgery is not possible due to serious comorbidities – sometimes a so-called tumor embolization carried out. The doctor closes the renal artery of the diseased kidney using a catheter. This stops the blood supply to the tumor – it can no longer grow, in some cases it even forms back. However, the effect is not permanent and only serves to relieve the symptoms.

Kidney cancer: disease progression and prognosis

In a kidney tumor, the chances of a cure depend primarily on how large the tumor is on the kidney and how far it has spread at the time of diagnosis. With the help of modern ultrasound technology even small tumors in the early stages can be easily recognized. Affected then usually have a good prognosis. Because the sooner kidney cancer is detected and treated, the better it can be treated. To detect kidney cancer at an early stage, patients should seek medical attention immediately if they see signs of urinary blood or frequent kidney pain. These symptoms are common in renal carcinoma but are not necessarily indicative of kidney cancer.

In a malignant kidney tumor, chances of recovery and life expectancy are also critically dependent on whether metastases are already present. Especially in the case of secondary tumors in the brain there is little possibility of therapy – the prognosis worsens significantly. In addition, the age of the patient and possible concomitant diseases have a further influence on the chances of a cure for kidney cancer.

In general, five years after the diagnosis “kidney cancer” still live 75 percent of men and 77 percent of women (relative 5-year survival). Those patients who have a chance of complete healing have a chance kidney cancer can be removed surgically.