Kidney cancer can affect both men and women, but are more common in men. In Singapore it is the 8th most frequently diagnosed cancer in men, affecting 10.1 per 100000 men. It is not among the top 10 cancers in women. The majority of people diagnosed to have kidney cancer are in their 60’s and 70’s.
Risk factors for kidney cancer include smoking, obesity and hypertension. Having a 1st degree relative with kidney cancer also increases the risk of kidney cancer.
In about 5% of cases, the increased risk for kidney cancer is passed down through the genes. Patients with hereditary kidney cancer are often diagnosed to have cancer in their 30’s.
There seems to be a trend towards kidney cancers being diagnosed at an early stage when they are still small. It the early stages, kidney cancer does not cause any symptoms.
In later stages when the cancer is larger, it may cause pain, blood in the urine, abdominal swelling, anaemia and weight loss.
Often, the first suspicion that a patient may have kidney cancer is during health screening, when ultrasound of the kidneys shows an unusual growth in the kidneys.
A CT scan of the kidneys is usually necessary to confirm the diagnosis of kidney cancer. A biopsy to sample kidney tissue is usually not necessary unless the CT scan does not provide sufficient information.
Ultimately, the final confirmation that the mass is a kidney cancer is by examination of the surgical specimen after surgical removal is performed.
CT scan showing a tumour in the right kidney
Kidney cancer has the tendency to spread to the lymph nodes and other organs such as the lungs. Once kidney cancer has been diagnosed, it is important to determine the extent or stage of the disease. This is important for prognosis and also to determine the type of treatment.
For purpose of determining the stage of the cancer, patients are usually recommended to go for a CT scan of the chest.
The treatment options for kidney cancer include surgery, thermal ablation therapies, active surveillance and anti-cancer medications.
Surgery – partial nephrectomy and radical nephrectomy
If the cancer is confined to the kidney, surgery is the recommended treatment.
If the tumour is small, the tumour can be removed while preserving the rest of the kidney which is unaffected. The medical term for this procedure is “partial nephrectomy”.
If the tumour is large, it is sometimes necessary to remove the entire kidney together with the tumour. The medical term for this procedure is “radical nephrectomy”.
Removing just the cancerous tissue is usually preferred over removing the entire kidney as it helps to preserve kidney function, and potentially reduces risk of cardiovascular problems in the long term. However, removing just the cancerous tissue is actually more difficult and has a higher risk of complications, compared to removing the entire kidney.
Partial nephrectomy (image from Cancer Research UK / Wikimedia Commons)
Radical nephrectomy (image from Cancer Research UK / Wikimedia Commons)
Techniques for surgery – laparoscopic (keyhole) and open approaches
It is often possible to perform the surgeries with laparoscopic surgery, which is performed using special instruments through small incisions. A surgical robot may be used to allow the surgeon to carry out more complicated cases. Laparoscopic surgery results in less pain and quicker recovery, compared with open surgery
If the tumour is too deep-seated or too large to be safely removed with laparoscopic surgery, the patient may be recommended to go for open surgery. The surgery is performed through an incision in the side or front of the abdomen.
Laparoscopic radical nephrectomy
Patient’s wounds after laparoscopic radical nephrectomy
Patient’s wound after open radical nephrectomy
Thermal ablation therapies
This involves placing one or several needle probes into the kidney tumour. Once the probes are activated, the tumour is either destroyed by freezing (cryoablation) or heat (radiofrequency ablation) . This method is less invasive compared to surgery, but there is a higher risk that the tumour will recur. This treatment is usually recommended for patients who are elderly or have medical problems that make them unfit for surgery.
This is an alternative approach for patients who are elderly and who have small incidentally detected kidney tumours. In some of these cases, the tumours are slow-growing and may not need treatment. The patients are followed up very closely and only treated if their tumours show signs of progression.
If the cancer is more advanced, or has spread to the lymph nodes or distant organs, medications such as immune checkpoint inhibitors, or tyrosine kinase inhibitors may be needed to control the disease.
Surgery for kidney cancer that has already spread
In addition to anti-cancer medications, surgery may sometimes be recommended for cancer that has already spread.