KIDNEY CANCER TREATMENT IN GERMANY

Renal cell carcinoma (renal adenocarcinoma)

Renal cell carcinoma (RCC) is the most common type of kidney cancer. Its symptoms include:

• haematuria;
• flank pain;
• a palpable mass;
• fever of unknown origin.

The disease is often asymptomatic, so it is usually suspected on the basis of incidental findings. The diagnosis is confirmed by CT or MRI, sometimes by biopsy. Management involves surgery in the early stages of the tumour process and targeted, experimental or palliative therapy in the advanced stages.

Adenocarcinoma accounts for 90–95% of primary malignant tumours of the kidney. Rarer primary kidney tumours include:

• transitional cell carcinoma;
• Wilms tumour;
• sarcoma.

Renal cell carcinoma is slightly more common in women than in men (male-to-female ratio of about 3:2). It usually affects people aged 50–70. The following risk factors are recognised:

• smoking, which doubles the risk (present in 20–30% of patients);
• obesity;
• excessive use of phenacetin;
• acquired cystic kidney disease in patients on haemodialysis;
• exposure to certain radiocontrast agents, asbestos, cadmium, leather tanning chemicals and petroleum products;
• certain genetic syndromes, notably von Hippel-Lindau disease.

Kidney cancer can lead to the formation of a thrombus in the renal vein, which sometimes extends into the inferior vena cava. Tumour invasion of the vein wall is rare. RCC most often metastasises to the lymph nodes, lungs, adrenal glands, liver, brain and bones.

Clinical presentation

Symptoms are usually absent until the advanced stages, by which time the tumour may already be large and metastatic. Gross or microscopic haematuria is the most common manifestation of the disease, followed by flank pain, fever of unknown origin and a palpable mass. Hypertension sometimes develops as a result of segmental ischaemia or compression of the renal pedicle. Paraneoplastic manifestations are seen in 20% of patients. Increased erythropoietin activity may lead to polycythaemia. Anaemia, however, may also occur. Hypercalcaemia is common and requires treatment. Thrombocytosis, cachexia or secondary amyloidosis may also develop.

Diagnosis

• Contrast-enhanced CT or MRI

Kidney cancer is most often detected incidentally during imaging of the abdomen (for example CT or ultrasound) performed for other conditions. In other cases the diagnosis is suspected clinically and confirmed by computed tomography of the abdomen or by MRI. A renal mass that enhances with contrast is suggestive of RCC.  Computed tomography and  magnetic resonance imaging also provide information on local spread and on lymph node and venous involvement. Magnetic resonance imaging provides the most complete information on extension of the tumour into the renal vein and the inferior vena cava. Ultrasound and IVU can visualise the tumour, but give less information on its characteristics and on the extent of the disease than CT and MRI. Imaging can often distinguish benign masses from malignant ones, but surgery is sometimes required to verify the diagnosis. Needle biopsy is not sufficiently sensitive in cases where the findings of other investigations are equivocal; it is recommended only when the tumour infiltrates tissue and has no clear margins, when the renal tumour may be a metastasis of a verified cancer at another site, or sometimes to confirm the diagnosis before starting chemotherapy for metastatic disease.

Before surgery, three-dimensional CT, CT angiography or MR angiography is used, particularly when nephron-sparing surgery is planned, in order to determine the nature of the RCC, assess the number of renal arteries more precisely and describe the vascular anatomy of the kidney. These imaging techniques have replaced aortography and selective renal arteriography.

A chest X-ray and measurement of renal enzyme levels are important. If abnormal findings are seen on the chest X-ray, a chest CT is performed. If alkaline phosphatase is elevated, a bone scan is required. Levels of electrolytes, calcium, urea and creatinine are measured. The latter two are usually unchanged, except when both kidneys are involved.

Staging

The information obtained from clinical examination allows preliminary staging. The TNM system (tumour, nodes, metastases) has recently been refined to achieve greater accuracy. At the time of diagnosis kidney cancer is localised in 45% of cases, locally advanced in 33% and metastatic in 25%.

Treatment

In the early stages of kidney cancer – surgical treatment.
In the advanced stages – palliative or experimental treatment

Radical treatments for kidney cancer

Radical nephrectomy (removal of the kidney, the adrenal gland, the perinephric fat and Gerota's fascia) is the standard surgical treatment for localised kidney cancer and offers the greatest likelihood of cure. When the results of open and laparoscopic procedures are compared − recovery is easier after laparoscopic surgery. Nephron-sparing surgery (partial resection of the kidney) may well be suitable for many patients, even those whose contralateral kidney is free of cancer cells, provided that the maximum diameter of the tumour is < 4−7 cm. Non-surgical methods of destroying kidney cancer by freezing (cryosurgery) or thermal energy (radiofrequency ablation) are not currently recommended as the primary treatment. These techniques are used in carefully selected patients, but long-term data on their effectiveness are not yet available.

When the cancer extends into the renal vein and the inferior vena cava, surgery may still be radical provided there are no lymph node or distant metastases.

If both kidneys are affected, bilateral resection is preferable to bilateral radical nephrectomy where technically feasible.

Radiotherapy is no longer combined with nephrectomy.