Kidney cancer, also known as renal cancer, is a type of cancer that starts in the cells of the kidney. The kidneys are bean-shaped organs located under the ribcage on both sides of the spine. Their main function is to filter out toxic waste products from the blood and excrete them as urine. When the cells of the kidney grow and divide uncontrollably, they can form a tumor, which may or may not be cancerous.
Types of Kidney Cancer:
There are several types of kidney cancer, but the most common type is renal cell carcinoma (RCC), which accounts for about 90% of all kidney cancers. RCC originates in the cells that line the small tubes (tubules) within the kidney that filter waste from the blood and produce urine. There are several subtypes of RCC, including clear cell RCC, papillary RCC, chromophobe RCC, and others.
Another type of kidney cancer is transitional cell carcinoma (TCC), also known as urothelial carcinoma, which originates in the cells of the renal pelvis, the area of the kidney where urine collects before it passes to the bladder. TCC is less common than RCC and is usually associated with a history of smoking.
Less common types of kidney cancer include Wilms tumor (usually affects children), renal sarcoma, and collecting duct carcinoma.
Causes and Risk Factors:
The exact cause of kidney cancer is unknown, but certain risk factors increase the likelihood of developing the disease. These risk factors include:
Smoking: Smokers are at a higher risk of developing kidney cancer than non-smokers.
Age: The risk of kidney cancer increases with age, with most cases diagnosed in people over 45 years of age.
Gender: Men are more likely to develop kidney cancer than women.
Obesity: People who are overweight or obese are at a higher risk of developing kidney cancer.
High blood pressure: Hypertension is a risk factor for kidney cancer.
Family history: People with a family history of kidney cancer are at a higher risk of developing the disease.
Exposure to certain chemicals: Exposure to certain chemicals, such as cadmium and organic solvents, has been linked to an increased risk of kidney cancer.
In its early stages, kidney cancer may not cause any noticeable symptoms. However, as the tumor grows, it may cause one or more of the following symptoms:
Blood in the urine (hematuria)
Pain in the side or back that doesn’t go away
Lump or mass in the side or abdomen
Unexplained weight loss
Loss of appetite