Kidneys, positioned on each side of the spine just below the rib cage, perform the crucial roles of filtering blood, removing waste, and balancing bodily fluids. These two bean-shaped organs are essential for maintaining overall health, regulating blood pressure, and ensuring that waste products are efficiently expelled from the body through urine.

Renal cell carcinoma (RCC), commonly known as kidney cancer, arises when malignant (cancer) cells form within the lining of the tubules in one or both of these kidneys. It means the healthy kidney cells in one or both kidneys grow out of control. This type of cancer disrupts the kidneys' ability to function properly and manage the body's fluids, salts, and elimination of wastes.

In Singapore, RCC represents about 1-2% of all cancers, with an annual diagnosis rate of approximately 2.4 men and significantly fewer women (1.3) of every 100,000 individuals, predominantly affecting those over 65. Despite being relatively uncommon in individuals younger than 50, the incidence of kidney cancer has been increasing annually by about 2-3%, according to HealthXchange. From 2017 to 2021, the Singapore Cancer Registry Annual Report recorded 1,734 cases among men, highlighting the disease's significant impact on this demographic.

Here are five key points everyone should know about kidney cancers:

1. Renal Cell Carcinoma and Other Kidney Cancers

Renal cell carcinoma is the predominant form of kidney cancer, comprising about 90% of cases, according to the Cancer Council. It typically originates as a single tumour within one kidney but can occasionally affect both. The most frequent subtype, clear cell renal cell carcinoma (ccRCC), begins in the kidney tubules that filter blood and produce urine.

Besides RCC, there are other less prevalent types of kidney cancer. Some of these include urothelial carcinoma, sometimes referred to as transitional cell carcinoma, which is treated similarly to bladder cancer. A less common type of kidney cancer is renal sarcoma, which arises from the connective tissues within the kidney and can spread to adjacent organs and bones if left unchecked.

In children, Wilms tumour is the most common kidney cancer, though it remains relatively rare.

2. The Symptoms of Kidney Cancer

Kidney cancer often remains undetected in its initial stages because it typically does not produce noticeable symptoms early on. However, as the tumour grows, symptoms may start to manifest, which can include blood in the urine (haematuria), persistent side or back pain not associated with injury, and an observable lump in the kidney area. Other signs might be fatigue, unexplained weight loss, fever not caused by an infection, and swelling of the ankles and legs.

These symptoms are common and can be associated with other health conditions like the presence of kidney stones, making it crucial to consult a doctor for a proper diagnosis. This is especially important as early detection is key, and kidney cancer found at an early stage often has a high rate of successful treatment, significantly improving the prognosis.

3. Risk Factors for Kidney Cancer

There are a few factors that can increase the risk of developing kidney cancer, and being aware of these can help in early detection and preventive strategies. Key risk factors include lifestyle choices such as smoking tobacco, which significantly doubles the risk compared to non-smokers.

Occupational exposure to harmful chemicals like arsenic and cadmium, commonly found in industries such as welding, painting, and farming, also raises the likelihood of developing kidney cancer.

Obesity, high blood pressure, and long-term dialysis are medical conditions that further enhance risk. Men are also more prone to kidney cancer than women, reflecting a gender disparity in incidence rates. Moreover, a family history of kidney cancer or genetic conditions like Von Hippel-Lindau syndrome can predispose individuals to this disease.

4. Tailored Approaches to Kidney Cancer Treatment

Treatment for kidney cancer varies widely depending on the stage and spread of the disease.

The treatment options for early kidney cancer may include: surgery and radiofrequency ablation, which uses thermal energy to destroy tumour cells.

For early-stage kidney cancer, surgical options are primary, including radical nephrectomy, where the entire kidney is removed, and partial nephrectomy, which targets only the cancerous part of the kidney. For smaller tumours or in cases where surgery poses too high a risk, non-invasive treatments like radiofrequency ablation are used to destroy cancer cells with high-energy waves.

For advanced kidney cancer, where the disease has spread beyond the kidney, the treatment strategy includes a combination of surgery and systemic therapies. Systemic therapies might involve immunotherapy, which boosts the body’s natural defences to fight cancer, or targeted therapies that attack specific aspects of cancer cells, like tyrosine kinase inhibitors, which are less likely to cause side effects compared to traditional chemotherapy.

Each treatment plan is tailored by oncologists based on the individual’s specific condition, taking into account factors such as the size of the tumour and its specific location. Regular monitoring through CT scans or ultrasounds is also a crucial part of managing the disease, particularly in observing the effectiveness of the treatment over time and adjusting as necessary.

5. Vigilance in Monitoring Kidney Health Post-Cancer

After treatment for kidney cancer, it's vital to monitor the unaffected kidney to catch any signs of recurrence early. Oncologists generally recommend a rigorous follow-up schedule, starting with imaging tests every three to six months for the first two years, followed by every six to twelve months thereafter.

The initial evaluation should include a complete staging evaluation (bloodwork, chest/abdomen/pelvis imaging) to exclude the possibility that the disease has already spread and give a thorough surveillance of the remaining healthy kidney.

The type of imaging—whether CT, MRI, or ultrasound—will vary, often alternating to minimise radiation exposure while providing a complete view of the kidney's condition. This personalised surveillance plan is essential to manage your health post-treatment effectively, adapting as needed based on your recovery and any new findings.

Addressing Kidney Cancer with OncoCare

At Oncocare, your cancer specialist is dedicated to guiding you through the complexities of kidney cancer treatment. Your cancer doctor in Singapore will also advise you on the risks of impaired kidney function depending on the presence of factors such as diabetes, high blood pressure and advanced age.

"Expert knowledge means better care for cancer"

Written by:
Dr Akhil Chopra
MBBS (Delhi)
American Board Certified (Intl Med)
American Board Certified (Hematology)
American Board Certified (Med Oncology)