Dr J.R Sathiyananthan, a Consultant Urologist at ParkCity Medical Centre, explains about kidney cancer and the measures that can be taken to minimise the risks of getting it.
Kidney cancer is a disease in which malignant tumour is found in one or both kidneys.
Kidney cancers account for a small proportion of all cancers, and the insidious nature of it makes early detection difficult.
In 2010, kidney cancer was reported to affect 1.9 in every 100,000 Malaysians, while 2020 data from World Health Organisation showing 2.1 per cent of all cancers in Malaysia to be kidney cancer.
Types of kidney cancer
“Kidney cancer is generally divided into two—primary and secondary kidney cancer.
“Primary kidney cancer comprises renal cell carcinoma, which accounts for 90 per cent of all kidney cancers, and other rare cancers such as lymphoma or medullary and collecting duct cancers.
“Secondary kidney cancer originates from cancers in other organs such as breast and colon. This in turn spreads to distant organs such as liver, lungs, and the kidney. This is not considered kidney cancer per se.,” says Dr Sathiya.
Although there are instances when kidney cancers are caught early, most are diagnosed at a more advanced stage. This is due to a variety of reasons, including the cancer being localised and growing without causing any pain or symptoms. Besides that, the nature of the kidneys lying deep within the body, small kidney tumours cannot be felt during a physical exam.
“At times when we examine patients for kidney cancer, it may have progressed to be locally advanced. Patients may have come in with flank pain, blood in urine, and sometimes the cancer is large enough to be palpable. The definite test which can confirm this is a contrasted multiphase CT scan, an imaging tool that provides accurate diagnosis. Besides that, percutaneous biopsies are also used in some circumstances to confirm the diagnosis and exclude metastasis from other cancers, bilateral cancers affecting both kidneys, or possibly benign tumours,” explains Dr Sathiya.
How the disease progresses
Currently there are no recommended screening protocols for kidney cancer in people who are not at increased risk. As of now, no screening test has shown to lower the overall risk of dying from kidney cancer.
Kidney cancer is known in some instances to grow aggressively and invade the surrounding bowel and solid organs, which is called local extension.
Other methods of progression could be blood borne, and spread to the lungs, liver, pancreas, lymph nodes, and bone. This is referred to as metastasis. When metastasis occurs, the outcome is expected to be poor as patient may not benefit from surgery.
The spread could occur anywhere between six months to years depending on the type of kidney cancer. Clinical data suggests that cancers larger than 3cm have higher tendency to spread compared to smaller ones. Nonetheless, the more common renal cell carcinoma has a slow progression rate compared to the rarer varieties, leading to the possibility of better outcome.
“Localised kidney cancer can be treated by surgery. This can be done by removing the entire kidney, also known as radical nephrectomy, or removing only the tumour, with multiple factors taken into consideration prior to this decision. For metastatic kidney cancer, there is evidence that removing the kidney may benefit the long-term systemic treatment, and it is still an evolving area. For those with advanced cancer where surgical options are not available, arterial embolisation to block blood supply to the tumour can treat some symptoms,” describes Dr Sathiya.
Although radical nephrectomy has been the mainstay of treatment for kidney cancer, the last 20 years has seen partial nephrectomy being the treatment of choice for most patients. This can be performed by open surgery, keyhole (laparoscopic) surgery, or robotically with the Da Vinci robot. The newer treatments include cryoablation and radio-frequency ablation, which can be used for tumours smaller than 4cm. Larger tumours may require multiple treatments.
“However, the evidence for the newer treatments is not strong and only supported by inferior clinical trials. Nevertheless, they are a viable option for weak patients who are unfit for surgeries or could be used in combination with surgery in familial kidney cancers where multiple tumours are found within the kidney,” Dr Sathiya elucidates.
Since it’s difficult to catch kidney cancer early, what can people do?
“The known risk factors associated with kidney cancer are smoking, obesity, and hypertension. If you can avoid those or keep them in check, you could reduce the chances of getting kidney cancer.
“Those who are at risk, for instance known family history of kidney cancer, should be aware of the symptoms and perform regular screening by ultrasound, blood, and urine test as prescribed by your Urologist,” highlights Dr Sathiya.