Kidney Cancer

The Function of the Kidneys and Complications Associated with Kidney Cancer

The kidneys are two bean-shaped organs located just below the rib cage on either side of the spine. Their main job is to filter waste, toxins, and extra water from the blood, forming urine. In addition, the kidneys regulate blood pressure, produce red blood cells through a hormone called erythropoietin, and maintain the balance of electrolytes in the body. When these organs are damaged or affected by disease, their ability to perform these vital roles can decline, leading to serious health problems.

Kidney cancer can interfere with all these important functions. It can disrupt the body’s filtration system, hormone production, and fluid balance. If not detected early, the disease may progress to kidney failure, cause uncontrolled high blood pressure, bone marrow suppression, or spread to vital organs such as the lungs, brain, and bones. In most cases, kidney cancer develops silently and is often discovered by chance during imaging tests for other medical issues. Understanding the risks and symptoms early can help improve outcomes through timely diagnosis and treatment.

Categories of Kidney Tumours

Kidney tumours are classified as either primary (starting within the kidney) or secondary (spreading from another organ).

• Primary Kidney Cancer: This type starts inside the kidney itself. The most common form is Renal Cell Carcinoma (RCC), which makes up about 90% of adult kidney cancers. RCC begins in the lining of the small tubes (renal tubules) in the kidney. Subtypes include:
  • Clear Cell RCC – most common form
  • Papillary RCC
  • Chromophobe RCC
  • Collecting Duct Carcinoma
  • Renal Sarcoma
  • Wilms’ Tumour – usually seen in children
• Secondary (Metastatic) Kidney Cancer: This type develops when cancer cells from another part of the body—such as the lungs, breast, or colon—spread to the kidney. Though less common, it usually indicates advanced disease.

Common Causes and Risk Factors

• Smoking and tobacco use
• Obesity and poor diet
• High blood pressure (hypertension)
• Chronic kidney disease or long-term dialysis
• Inherited conditions like Von Hippel-Lindau disease
• Occupational exposure to chemicals such as asbestos or cadmium

Symptoms of Kidney Cancer

Kidney cancer may not cause any noticeable signs in the early stages. As the disease progresses, symptoms may include:

• Blood in the urine (hematuria)
• Pain in the lower back or side (flank pain)
• Swelling or lump in the abdomen
• Unexplained weight loss or fatigue
• Recurring fever not caused by infection
• High blood pressure
• Swelling in the ankles or legs
• Bone pain (in advanced cases)

Diagnosis of Kidney Cancer

Diagnosis involves several steps to confirm and determine the stage of the disease:

• Medical History & Physical Exam: The doctor reviews symptoms, risk factors, and checks for any mass or tenderness in the abdomen.
• Lab Tests: Includes urinalysis (to detect blood or protein) and blood tests for kidney function and calcium levels.
• Imaging Tests:
  • Ultrasound: Initial test to identify kidney masses.
  • CT Scan: Gold standard for evaluating tumour size, shape, and spread.
  • MRI: Useful for patients allergic to contrast or for assessing nearby blood vessels.
  • PET-CT / Chest X-ray: Detects cancer spread to other organs.
• Biopsy: Sometimes done to confirm the type of cancer before non-surgical treatment.
• Staging: The TNM system (Tumour, Node, Metastasis) helps doctors plan the most effective treatment.

Treatment Options for Kidney Cancer

Treatment depends on the tumour’s type, size, and spread, as well as the patient’s general health. The main treatment options include:

A. Conventional Treatments

• Partial Nephrectomy (Kidney-Sparing Surgery): Removes only the tumour and a small part of healthy tissue, preserving kidney function.
• Radical Nephrectomy: Removes the entire kidney along with surrounding tissues and lymph nodes for large or invasive cancers.
• Radiation Therapy: Used mainly for symptom relief or to control metastases when surgery isn’t possible.
• Chemotherapy: Typically not effective for most RCC cases but may help in rare cancer subtypes like collecting duct carcinoma or Wilms’ tumour.

B. Advanced and Modern Therapies

• Minimally Invasive Techniques:
  • Cryoablation: Destroys cancer cells by freezing them under image guidance. Ideal for small tumours or patients unfit for surgery.
  • Robotic/Laparoscopic Surgery: Offers smaller cuts, faster recovery, and less pain compared to open surgery.
• Targeted Therapy: Uses drugs that block cancer cell growth and blood supply.
  • Tyrosine Kinase Inhibitors (TKIs) – Sunitinib, Sorafenib, Pazopanib, Axitinib
  • mTOR Inhibitors – Temsirolimus, Everolimus
• Immunotherapy: Boosts the immune system to fight cancer. Common agents include:
  • Anti–PD-1 / PD-L1 drugs – Nivolumab, Pembrolizumab
  • CTLA-4 inhibitor – Ipilimumab
  Combination regimens like Nivolumab + Ipilimumab or Avelumab + Axitinib have shown strong results for advanced RCC.

Prevention and Lifestyle Management

Though kidney cancer cannot always be prevented, healthy lifestyle choices can reduce risk:

• Quit smoking completely
• Maintain a healthy body weight
• Keep blood pressure and diabetes under control
• Stay hydrated and follow a kidney-friendly diet
• Avoid exposure to harmful chemicals (like cadmium or asbestos)
• Schedule regular health check-ups and imaging if you are at higher risk

Prognosis and Survival

Outcomes depend on the stage and type of kidney cancer. Localised cases have a high survival rate—about 93% over five years. The rate decreases for regional or metastatic disease, but new targeted and immune-based therapies are improving results every year. Regular follow-ups after treatment are essential to monitor for recurrence or secondary complications.

Conclusion

Kidney cancer is a complex but increasingly manageable disease with modern treatment options. Because the kidneys play such an important role in filtration, hormone regulation, and fluid balance, early diagnosis and proper treatment are key. Surgical removal remains the mainstay for early-stage disease, while newer therapies like immunotherapy and targeted treatment have brought hope to patients with advanced stages. Maintaining a healthy lifestyle and regular screening remain the most effective ways to prevent and control kidney cancer.