Kidney cancer is not usually top of mind for people who feel well. Yet that is one reason it can go unnoticed.

Early kidney cancer often causes no obvious symptoms.

“Kidney cancer can be highly treatable, and often curable, when it is found at an early stage,” — Dr Christopher Lee Kheng Siang

The most common type of kidney cancer in adults is renal cell carcinoma (RCC). It may appear as a solid growth in the kidney or, less commonly, as a complex kidney cyst. While many kidney cysts and some growths are benign, suspicious or malignant lesions need careful assessment and timely treatment.

“Kidney cancer can be highly treatable, and often curable, when it is found at an early stage,” says Dr Christopher Lee Kheng Siang, Consultant Urologist & Robotic Surgeon at Sunway Medical Centre, Sunway City. “The challenge is that small kidney tumours are often silent.”

Why kidney cancer may be missed

Early kidney tumours rarely cause pain or other noticeable changes. Many are discovered incidentally when a person undergoes an ultrasound, CT scan or MRI scan for another health concern or as part of a medical assessment.

Symptoms are more likely to occur when a tumour becomes larger or the disease is more advanced. These can include:

• Blood in the urine, which may be visible or detected on a urine test
• Persistent pain in the side, abdomen or lower back
• A lump or swelling in the abdomen
• Ongoing tiredness
• Reduced appetite
• Unexplained weight loss

These symptoms do not necessarily mean kidney cancer. Blood in the urine, for example, may also be caused by infection, kidney stones or other urinary conditions. However, visible blood in the urine should always be assessed promptly by a doctor.

How suspicious kidney masses are assessed

If a kidney mass or complex cyst is detected, patients are usually referred to a urologist for further assessment.

“A contrast-enhanced CT scan is commonly used to assess the kidneys and urinary tract in detail,” Dr Christopher explains. “It helps us determine whether a lesion appears suspicious for cancer, assess its size and location, and check whether there are signs that it has spread.”

CT scans can identify and characterise many kidney tumours reliably. In selected cases, an MRI scan may be used instead, particularly when CT contrast is unsuitable or when further detail is needed.

A biopsy is not required before surgery in every case. When imaging strongly suggests a localised kidney cancer that can be removed safely, surgery may proceed without a biopsy.

However, a biopsy can be helpful when scan findings are unclear or when the result could affect the choice between surveillance, ablation, surgery or drug treatment.

Earlier diagnosis can preserve kidney function

For many people with localised RCC, surgery offers a high chance of cure.

Where possible, surgeons aim to remove the tumour while preserving the rest of the kidney. This procedure is called a partial nephrectomy.

“Partial nephrectomy is preferred when it can be done safely without compromising cancer control,” says Dr Christopher. “Preserving kidney tissue is particularly important for younger patients, people with only one functioning kidney, and those who may be at risk of chronic kidney disease.”

In some cases, the tumour’s size, position or complexity means that removing the whole kidney, known as a radical nephrectomy, is the safer option. Most people can live well with one healthy kidney, although kidney function should be monitored over time.

Not every kidney mass requires immediate surgery. Depending on the size and appearance of the lesion, its rate of growth, and a patient’s age and overall health, doctors may recommend active surveillance or other treatments.

Smaller incisions, faster recovery

Kidney surgery may be performed through open surgery, laparoscopy or robotic-assisted techniques.

Minimally invasive approaches, including laparoscopic and robotic-assisted surgery, use smaller incisions than traditional open surgery. For suitable patients, this can mean less post-operative pain, a shorter hospital stay and a quicker return to normal activities.

“When the whole kidney needs to be removed, laparoscopic or robotic surgery can often be considered,” Dr Christopher says. “Open surgery remains important in selected complex cases, including very large tumours or cases involving major blood vessels.”

The best approach depends on the tumour and the individual patient. It should be decided after discussion with a urologist who can explain the expected benefits, risks and alternatives.

The role of robotic-assisted surgery

Robotic-assisted surgery can help surgeons perform certain complex kidney-preserving operations through minimally invasive incisions.

“The system provides a magnified, three-dimensional view and instruments designed to move with a high degree of precision,” Dr Christopher explains. “This can assist the surgeon when removing a tumour and reconstructing the kidney, particularly in more technically challenging partial nephrectomies.”

He stresses that robotic technology does not perform surgery independently.

“The surgeon remains in control throughout the operation. The robotic system follows the surgeon’s movements and does not make automated decisions,” he says.

What people should know about screening

Because kidney cancer can be silent in its early stages, many tumours are found unexpectedly during imaging performed for other medical reasons.

However, routine annual screening specifically for kidney cancer is not currently recommended for every symptom-free, average-risk adult.

People with a strong family history of kidney cancer, a known inherited cancer syndrome, certain long-term kidney conditions or other individual risk factors should speak to their doctor about whether they may need personalised monitoring.

The most important message is not to ignore concerning symptoms, particularly blood in the urine, persistent flank pain, unexplained weight loss or a new abdominal lump.

“Kidney cancer can often be treated successfully when identified early,” says Dr Christopher. “If you have symptoms or are concerned about your risk, speak with your doctor so that appropriate tests and follow-up can be arranged.”

The medical information of this article is contributed by Dr Christopher Lee Kheng Siang, Consultant Urologist & Robotic Surgeon, Sunway Medical Centre, Sunway City.