- They are the most common renal carcinoma in adults.
- They rarely present before the age of 40, and the average age of onset is 65-75
- Twice as common in men as women.
This is largely unknown, however some factors are suspected to precipitate this disease:
- Exposure to oestrogens
- Exposure to cadmium
- The disease is more commonly found in urban and industrial areas than in rural areas.
- Incidence is 10 per 100 000 in males, and 5 per 100 000 in females.
- Rarely, the disease may run in families, in which case, there is a defect on chromosome 3p.
- A similar defect is found in von Hippel-Lindau disease – an inherited condition where there are cysts and tumours of the kidney, pancreas, adrenal gland, epididymis, cerebellum and spinal cord. 2/3 of patients with this disease will develop renal carcinoma that is often bilateral and multifocal.
- We can therefore deduce that it is the same tumour suppressor gene that is mutated in von Hippel-Lindau disease that is also implicated in the formation of renal cell carcinoma. Deletion of the short arm of chromosome 3 is a common finding in sporadic RCC. – remember that this deletion won’t cause von Hippel-Lindau disease because the disease is caused by an inherited mutation in every cell of the body, whereas in RCC, there will only be deletion of this segment in one renal cell, that then becomes cancerous.
- Haematuria – 60%- this is caused by the spread of the tumour to the renal pelvis, which usually occurs very early on. From here it may spread to the renal vein and IVC.
- Flank/loin pain (40%)
- Palpable mass (25%)
- These first three signs are the ‘classic’ ones, but actually only occur in 15% of patients.
- Weight loss (30%)
- Raised ESR
- Polycythaemia (5%)
- Hypertension (30%) – due to secretion of renin by the tumour
- Anaemia (30%) – due to suppression of EPO by the tumour
- Pyrexia of unknown origin (PUO) (20%)
- Varicocoele (rare) – this occurs as a result of invasion of the left renal vein by the tumour, which may then affect drainage of blood from the testes.
- Locally this is very common
- Bone metastasis can occur anywhere in the body
- Lymphatic spread it via the para-aortic nodes.
- USS – this will show any lumps on the kidney, and also lets you examine the renal vein and inferior vena cava (there may be signs of invasion). It allows you to differentiate between tumour and renal cyst.
- Excretion urography – shows a space occupying lesion in the kidney, and in 10% of cases, it will be calcified.
- Tumours of <3cm may be missed by both of these methods.
- CT scan – will show similar things as USS, but can shows tumours as small as 1cm. About 50% of tumours less than 1cm in diameter will also be detected.
- CT is also able to detect involvement of the renal vein and inferior vena cava – which are poor prognostic signs.
- Raised ESR
- Abnormal liver biochemistry – this will return to normal after successful treatment.
- MRI – the most useful tool for tumour staging (better than CT).
- LFTs – are often abnormal, but will return to normal levels after surgery.
- USS – to asses original tumour size (<3cm is said to be ‘small’)
- MRI (perhaps with image guided biopsy) – will show lymphatic and venous involvement
- Bone scan
- It is almost impossible for the surgeon to know what type of treatment will be needed until ‘they get in there’
- For those with many metastasis, or invasion of the vena cava etc, then prognosis is generally very poor. Nephrectomy may still be performed to provide symptomatic relief, but most patients are unlikely to live longer than a year.
- Medroxyprogesterone acetate may be useful in cases of metastatic disease.
- Radiotherapy is only useful in treating bone mets.
- Immunotherapy has been shown to be effective – treatment with interferon and interleukin-2 in patients with extensive disease is beneficial in 10-40% of cases, not necessarily ‘curing’ the disease, but it may prolong the patient’s life. In such cases, a nephrectomy will usually have been performed previously. Metastasis in the lungs are the most likely to respond to this sort of treatment.
5 year survival:
- Tumours confined to kidney – 60-70%
- Lymph node spread – 15-35%
- Metastatic disease – 5%