Renal Cancers - Symptoms, Risk factors and Treatment

The kidneys, two in number, are functionally vital organs in the human body. They are responsible for filtering out waste products from the body. 

Renal cancer or kidney cancer refers to cancer originating from the kidneys.

There are different types of renal cancers, the most common being renal cell carcinoma (RCC), followed by nephroblastoma (Wilms tumor).

Renal cell carcinoma:

This type of renal cancer originates from the layer of cells (epithelium) of the renal tubules. The renal tubules are tiny filtering units that take part in urine formation. Renal cell carcinoma can be divided into three different types on the basis of its origin:

• Clear cell carcinoma
• Papillary renal cell carcinoma
• Chromophobe renal carcinoma

Risk factors for renal cell carcinoma:

Certain factors predispose a person to an increased risk of getting renal cell carcinoma:

Age: Renal cancers are more common during the 60s and 70s.

Gender: Men are more likely to get renal cancer as compared to women.

Smoking: Smokers are at high risk of getting renal cancer.

Hypertension: The risk of getting renal cancer is higher in hypertensive patients.

Bodyweight: Obesity increases the risk of getting renal cancer.

Exposure to cadmium: people who have had occupational exposure to cadmium are at a high risk of getting renal cancer. The risk increases if cadmium exposure is combined with smoking.

Dialysis: patients who undergo long-term dialysis can develop acquired polycystic kidney disease, a condition in which multiple cysts form in the kidney. Acquired polycystic kidney disease greatly increases the risk of developing renal cancer.

Genetics: A family history of renal cancer can increase the risk of getting it in an individual.

What causes renal cancer?

The exact cause of renal cancer is unknown. However, problems with the genes (genetic mutations) have been identified in causing different renal cancers. Some genes promote the division of cells (a proto-oncogene) while some genes, also known as tumor suppressor genes, control the division of cells and prevent cancer development. Increased expression of proto-oncogenes and deletion or decreased expression of tumor suppressor genes result in an uninhibited cellular division that gives rise to cancer.

Symptoms of renal cancer:

The signs and symptoms of renal cancer include:

• Hematuria (urine with blood)
• Pain in the lower abdomen
• Fever
• Loss of appetite
• Weight loss
• Malaise 

Diagnosis of renal cancer:

To diagnose renal cancer, the following tests may be suggested:

• Ultrasonography
• CT scan
• MRI
• Kidney biopsy 
• Blood tests

Complications of renal cancer:

The complications of renal cancer include:

Spread of cancer: As cancer grows in size, it can invade the renal vein and can get into the inferior vena cava, as far as the heart. It can also spread to other neighboring organs, affecting their function.

Other than the spread of cancer, the following complications can arise:

• Hypercalcemia (too much calcium in the blood)
• Hypertension (increased blood pressure )
• Polycythemia (too much red blood cells)

Treatment of renal cancer:

The treatment of renal cancer usually involves surgical resection of the areas affected by cancer. Along with that, radiation therapy may be started if cancer has spread to different areas such as bone and brain. Chemotherapy is not very effective for renal cancer and may not be given.

Wilms tumor:

Wilms tumor or nephroblastoma is a tumor of the kidney which mostly affects children. The cause of Wilms's tumor is unknown.

Conclusion:

Renal cancer is a malignancy of the kidneys. The survival rate depends upon the spread of cancer. If detected at an early stage, the prognosis can be good. To prevent renal cancer, smoking cessation, maintaining a healthy body weight, and controlling hypertension are recommended.