Kidney cancer, also known as renal cancer, occurs when cells in the kidneys grow uncontrollably, forming a tumor. The kidneys are two bean-shaped organs located on either side of the spine, responsible for filtering waste from the blood and producing urine. Kidney cancer can affect various parts of the kidney, but the most common type is renal cell carcinoma (RCC), which begins in the lining of the small tubes in the kidney.

Types of Kidney Cancer

1. Renal Cell Carcinoma (RCC):

   • The most common type, accounting for about 85% of kidney cancer cases.

   • Subtypes include clear cell RCC, papillary RCC, and chromophobe RCC.

2. Urothelial Carcinoma:

   • Begins in the renal pelvis (the part of the kidney where urine collects before moving to the bladder).

   • Shares similarities with bladder cancer.

3. Wilms Tumor:

   • A rare type of kidney cancer that primarily affects children.

4. Sarcoma:

   • A rare type that starts in the kidney’s connective tissues.

5. Lymphoma:

   • Rarely, the kidneys can be involved in lymphoma, a type of cancer that begins in the immune system cells.

Symptoms of Kidney Cancer

In its early stages, kidney cancer often doesn’t cause noticeable symptoms. As the cancer progresses, symptoms may include:

• Blood in the urine (hematuria)

• Persistent pain in the side or lower back

• A lump or mass in the abdomen or side

• Unexplained weight loss

• Fatigue

• Fever not caused by an infection

• Loss of appetite

Risk Factors

• Smoking: Increases the risk of developing kidney cancer.

• Obesity: Excess weight can lead to hormonal changes that increase risk.

• High Blood Pressure: Hypertension is linked to a higher risk of kidney cancer.

• Family History: Having a family history of kidney cancer increases your risk.

• Chronic Kidney Disease: Long-term kidney disease or dialysis can raise the risk.

• Certain Genetic Conditions: Conditions like von Hippel-Lindau disease and hereditary papillary RCC are linked to a higher risk of kidney cancer.

Diagnosis

Diagnosis typically involves a combination of the following:

• Imaging Tests: Such as ultrasound, CT scans, or MRIs to visualize the kidneys.

• Urinalysis: To check for blood or other abnormalities in the urine.

• Blood Tests: To assess kidney function and overall health.

• Biopsy: In some cases, a small sample of tissue is taken to confirm the diagnosis.

Treatment Options

Treatment for kidney cancer depends on the stage and type of cancer, as well as the patient’s overall health:

1. Surgery:

   • Partial Nephrectomy: Removal of the tumor while preserving the rest of the kidney.

   • Radical Nephrectomy: Removal of the entire kidney, and sometimes surrounding tissues and lymph nodes.

2. Ablation and Other Local Therapies:

   • Cryoablation: Freezing the tumor to kill cancer cells.

   • Radiofrequency Ablation (RFA): Using heat to destroy the tumor.

3. Targeted Therapy:

   • Drugs that target specific genes or proteins that help cancer cells grow. Examples include sunitinib, pazopanib, and axitinib.

4. Immunotherapy:

   • Boosts the body’s immune system to attack cancer cells. Examples include immune checkpoint inhibitors like nivolumab and pembrolizumab.

5. Radiation Therapy:

   • Typically used when surgery is not an option, or to relieve symptoms caused by cancer that has spread.

6. Chemotherapy:

   • Less commonly used for kidney cancer, but may be an option for certain types like sarcoma.