The majority of kidney cancers are discovered incidentally during ultrasonography carried out for other reasons.
The classical triad of flank pain, a palpable mass and haematuria is rare these days.
Other possible symptoms are weight loss, fever and lethargy.
Kidney cancer is a common cause of hypersedimentation. Anaemia and microscopic haematuria are common.
Investigations
Ultrasonographic examination is the procedure of choice if kidney cancer is suspected.
Laboratory investigations: ESR, basic blood count with platelet count, creatinine, ALP, chemical urinalysis
The presence of a tumour is usually confirmed with contrast-enhanced computed tomography (CT) scanning of the chest and abdomen. CT scanning is used to assess the size, location and vascular anatomy of the tumour, the health of the contralateral kidney as well as possible tumour involvement in the renal vein, inferior vena cava, lymph nodes, adrenal glands or liver.
A CT scan is normally very sensitive in detecting malignant tumours. Renal oncocytoma and some angiomyolipomas are benign tumours and may cause diagnostic problems warranting a core needle biopsy of the tumour.
A histological confirmation must always be obtained before proceeding with ablative (radiofrequency or cryoablation) or oncological therapy.
Surgical resection is the only curative treatment of kidney cancer.
The surgical approach is chosen according to the size and location of the tumour and the health of the contralateral kidney. The aim is to spare as much functioning kidney tissue as possible as this will improve the patient's prognosis. Partial nephrectomy is recommended for tumours that are smaller than 4 cm. Units performing kidney cancer surgery should have readiness for the selection of the operation method on an individual basis: partial or complete nephrectomy through open surgery or laparoscopy. The majority of operations are nowadays laparoscopic. The ipsilateral adrenal gland can often be spared.
Less strenuous treatment methods can be used in patients with high surgical risk: radiofrequency ablation, microwave ablation, laser ablation or cryoablation.
The treatment of a cancer that has metastasized at the time of diagnosis is palliative: nephrectomy and/or pharmacotherapy. In a metastasized cancer of low or moderate risk, a combination of nephrectomy and pharmacotherapy is used, but in a high-risk metastasized cancer nephrectomy is not beneficial. Tyrosine kinase inhibitors that supress angiogenesis, such as sunitinib, sorafenib, pazopanib, axitinib and cabozantinib, form the largest group of drugs. Also the combination of anti-VEGF antibody bevacizumab and interferon, or mTOR inhibitors, such as everolimus or temsilorimus, can be considered. The newest drugs for kidney cancer are the so-called immune checkpoint inhibitors which enhance the immune system's function against cancer cells. The anti-PD1 antibody nivolumab is the most used drug of this group.
In the treatment of symtoms associated with the tumour, such as bleeding and pain, angiographic embolization may be usable. Radiotherapy is often of benefit in painful bone metastases. Also denosumab may be used as supportive therapy for the skeletal system, particularly if bone metastases are associated with hypercalcaemia.
Follow-up
Aims to detect solitary, treatable metastases.
After surgery of localized kidney cancer, metastases appear in 20-40% of the patients.
After radical surgery, the follow-up is carried out in the urological unit every 3-6 months for 1-2 years, and thereafter in a health centre. Patients with low recurrence risk are followed up for a period of 5 years, and in high risk diseases a follow-up period of 10 years is recommended.
The most essential imaging study is whole-body CT scan. In patients with low recurrence risk it can every now and then be replaced by abdominal ultrasonography and chest x-ray. The most important laboratory investigations are plasma creatinine, ALP and chemical urinalysis.